GettingToGripsWithALAR
getting to
grips with
Approach-and-Landing
Accidents Reduction
A Flight Operations View
Issue 1
October 2000
AIRBUS INDUSTRIE
Flight Operations Support – Customer Services Directorate
Getting to Grips with
Approach-and-Landing Accidents Reduction
Terms of Reproduction
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2002 – All Rights Reserved
The statements made herein do not constitute an offer. They are expressed on the
assumptions shown and are expressed in good faith. Where the supporting grounds for these
statements are not shown the Company will be pleased to explain the basis thereof.
In the interest of aviation safety, Airbus encourages the wide use of the ALAR Briefing Notes
( in printed format or in electronic format ) as suggested in the chapter Introducing the
Briefing Notes ( Page 2 – How to Use and Implement the Briefing Notes ? ).
Use and duplication (in whole or part, in all media) of the ALAR Briefing Notes is authorized for
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The users shall reproduce the copyright “
of the copyright owner on any duplication.

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Duplications shall credit Airbus and the Flight Safety Foundation, for any reference to or use of
the contents of the ALAR Briefing Notes, that have been developed by Airbus in the frame of an
international industry task force led by the Flight Safety Foundation.
In case of translation, the translation shall not modify the intent and spirit of the original text.
In case of partial reprint, the abstract shall not alter the contents from its original context.
The ALAR Briefing Notes are provided under the expressed condition that Airbus shall have no
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duplication, adaptation or translation and for the updating and revision of any duplicated
version.
For any further information or assistance, do not hesitate to contact us.
Training and Flight Operations Support & Line Assistance
Customer Services Directorate
Attention Michel TREMAUD
Operational Standards and Flight Safety Projects
1, Rond Point Maurice Bellonte, BP 33
31707 BLAGNAC Cedex – FRANCE
Telex : AIRBU 530526F
SITA : TLSBI7X
Telefax : +(33).5.61.93.29.68 or +(33).5.61.93.44.65
E-mail : michel.tremaud @ airbus.fr
AIRBUS INDUSTRIE
Flight Operations Support
Getting to Grips with
Approach-and-Landing Accidents Reduction
Foreword
•
Provides or suggests company’ accidentprevention-strategies and/or personal lines-ofdefense (for incident/accident prevention
purposes and/or for correction purposes);
•
The brochure consists of a set of Approach-andLanding Briefing Notes.
Establishes a summary of operational and
training key points;
•
Provides cross-reference to the associated or
related Briefing Notes; and,
Each Briefing Note:
•
References the relevant ICAO, U.S. FAR and
European JAR documents.
The brochure Getting to Grips with Approach
and Landing Accidents Reduction provides an
overview of the flying techniques and operational
aspects
involved
in
approach-and-landing
accidents.
•
Presents the subject using statistical data;
•
Emphasizes the applicable standards and best
practices (standard operating procedures,
supplementary
techniques,
operational
recommendations and training guidelines);
•
Discusses the factors that may lead flight crews
to deviate from relevant standards (for eyeopening purposes);
Should any deviation appears between the
information provided in this brochure and that
published in the applicable Airplane Flight Manual
(AFM), Flight Crew Operating Manual (FCOM),
Quick Reference Handbook (QRH) and Flight Crew
Training Manual (FCTM), the latter shall prevail at
all times.
All readers are encouraged to submit their questions
and suggestions, regarding this document, to the
following address :
Airbus Industrie
Training and Flight Operations Support
Customer Services Directorate
Attention Michel TREMAUD
Operational Standards Development
1, Rond Point Maurice Bellonte, BP 33
31707 BLAGNAC Cedex – FRANCE
Telex : AIRBU 530526F
SITA : TLSBI7X
Telefax : +(33).5.61.93.29.68 or +(33).5.61.93.44.65
E-mail : michel.tremaud @ airbus.fr
AI/ST-F 94A.0093/00
AIRBUS INDUSTRIE
Flight Operations Support
Getting to Grips with
Approach-and-Landing Accidents Reduction
Table of Contents
Foreword
2 - Crew Coordination
Briefing Notes Summary
2.1 - Human Factors in Approach-and-Landing
Accidents
2.2 - CRM Issues in Approach-and-landing
Accidents
ALAR Task Force – Conclusions and
Recommendations
2.3 - Effective Pilot/Controller Communications
2.4 - Intra-Cockpit Communications – Managing
Interruptions and Distractions
Introducing the Briefing Notes
Glossary of Terms and Abbreviations
3 - Altimeter and Altitude Issues
3.1 - Altimeter Setting – Use of Radio Altimeter
Briefing Notes :
3.2 - Altitude deviations
1 - Standard Operating Procedures (SOPs)
4 - Descent and Approach Management
1.1 - Operating Philosophy
4.1 - Descent and Approach Profile Management
1.2 - Optimum Use of Automation
4.2 - Energy Management during Approach
1.3 - Operations Golden Rules
5 - Approach Hazards Awareness
1.4 - Standard Calls
5.1 - Approach Hazards Awareness - General
1.5 - Normal Checklists
5.2 - Terrain Awareness
5.3 - Visual Illusions Awareness
1.6 - Approach and Go-around Briefings
5.4 - Windshear Awareness
Table of Contents
Page 1
AIRBUS INDUSTRIE
Flight Operations Support
Getting to Grips with
Approach-and-Landing Accidents Reduction
6 - Readiness and Commitment to
Go-around
8 - Landing Techniques
8.1 - Preventing Runway Excursions and Overruns
6.1 - Being Prepared to Go-around
8.2 - The Final Approach Speed
6.2 - Flying a Manual Go-around
8.3 - Factors Affecting Landing Distance
6.3 - Terrain Avoidance ( Pull-up ) Maneuver
8.4 - Optimum Use of Braking Devices
8.5 - Landing on Wet or Contaminated Runway
6.4 - Bounce Recovery – Rejected Landing
8.6 - About Wind Information What’s your Current Wind ?
7 - Approach Techniques
7.1 - Flying Stabilized Approaches
8.7 - Crosswind Landing
7.2 - Flying Constant-Angle non-Precision
Approaches
7.3 - Acquisition of Visual References
7.4 - Flying Visual Approaches
Table of Contents
Page 2
AIRBUS INDUSTRIE
Flight Operations Support
Getting to Grips with
Approach-and-Landing Accidents Reduction
Briefing Notes Summary
Introduction
The scope of this brochure extends beyond
approach-and-landing accidents, by addressing:
The brochure Getting to Grips with Approachand-Landing Accidents Reduction provides
operational recommendations and guidelines to
implement the conclusions and recommendations of
the following international working groups:
•
Wind shear awareness in all flight phases,
including takeoff and landing;
•
Terrain awareness in all flight phases;
•
Descent-and-approach preparation;
•
Flight Safety Foundation (FSF) – CFIT and
Approach-and-Landing Accidents Reduction
(ALAR) Task Force; and,
•
Initial descent management; and,
•
Go-around and missed-approach.
U.S. Commercial Aviation Safety Team (CAST)
– Joint Safety Implementation Team (JSIT) for
ALAR.
This extended scope addresses the type of events
and causal factors involved in approximately 70 %
of total hull losses.
•
Statistical Data
Conclusions and Recommendations
Operations and Training Issues
Approach-and-landing accidents (i.e., accidents that
occur during initial approach, intermediate
approach, final approach or landing) represent every
year 55 % of total hull losses and 50 % of fatalities.
The conclusions and recommendations of the Flight
Safety Foundation ALAR Task Force are appended
to this Briefing Notes Summary.
These conclusions identify the following operations
and training issues as frequent causal factors in
approach-and-landing accidents, including those
involving CFIT:
These statistical data have not shown any down
trend over the past 40 years !
The flight segment from the outer marker to the
completion of the landing roll represents only 4 % of
the flight time but 45 % of hull losses.
The following types of events account for 75 % of
approach-and-landing incidents and accidents:
•
Standard operating procedures;
•
Decision-making in time-critical situations;
•
Decision to initiate a go-around when warranted;
•
Rushed and unstabilized approaches;
•
Pilot/controller understanding of each other’
operational environment;
•
CFIT (including landing short of runway);
•
Loss of control;
•
Runway overrun;
•
Pilot/controller communications;
•
Runway excursion; and,
•
•
Non-stabilized approaches.
Awareness of approach hazards (visual
illusions, adverse wind conditions or operations
on contaminated runway); and,
•
Terrain awareness.
Briefing Notes Summary
Page 1
AIRBUS INDUSTRIE
Flight Operations Support
Operational
Guidelines
Recommendations
Getting to Grips with
Approach-and-Landing Accidents Reduction
and
Based on the conclusions and recommendations of
the FSF and CAST working groups, Airbus Industrie
has developed a set of Approach-and-Landing
Briefing Notes to provide background information,
operational
recommendations
and
training
guidelines for the prevention of approach-andlanding incidents and accidents.
The Approach-and-Landing Briefing Notes address
thirty-three operational and training subjects
grouped into eight thematic chapters.
The following overview of the Approach-andLanding Briefing Notes highlights the main
operational
recommendations
and
training
guidelines applicable for each theme and subject.
These recommendations and guidelines should be
considered for incorporation in the operator’s
operations manual, aircraft operating manual and
training manual, and emphasized during transition
training, line training, recurrent training, line checks
and line audits.
•
Approach and go-around briefings;
•
Altimeter setting and cross-check procedures;
•
Descent profile management;
•
Energy management during approach;
•
Terrain awareness;
•
Approach hazards
illusions);
•
Use of radio altimeter;
•
Elements of a stabilized approach and approach
gates;
•
Approach procedures and
various types of approaches;
•
Landing and braking techniques for various
types of runway contaminants and wind
conditions; and,
•
Readiness and commitment to go-around
(i.e., GPWS/TAWS warning, unstabilized
approach, bounce recovery).
awareness
(e.g., visual
techniques
for
1.2 - Optimum Use of Automation
1 - Standard Operating Procedures (SOPs)
For an optimum use of automation, the following
should be promoted during transition training and
recurrent training:
1.1 - Operating Philosophy
•
Understanding the integration of AP/FD and
A/THR modes (i.e., pairing of modes);
Company policies, technical and CRM training, line
checks and line audits should:
•
Understanding all mode transition and reversion
sequences;
•
Promote strict adherence to SOPs; and,
•
Understanding pilot-system interfaces for:
•
Identify and address the reasons for intentional
or inadvertent deviations from SOPs.
− Pilot-to-system communication (i.e., for
modes engagement and target selections);
and,
Without strict adherence to SOPs, the effective
implementation of CRM practices is not possible.
− System-to-pilot feedback (i.e., for modes and
targets cross-check);
SOPs should emphasize the following aspects
frequently
involved
in
approach-and-landing
accidents:
•
Task sharing;
•
Rules for use of automation;
•
Standard calls;
•
Use of normal checklists;
•
Awareness of available guidance (i.e., AP/FD
and A/THR engagement, modes armed or
engaged and selected targets; as annunciated
on PFD - FMA and scales - and on ND);
•
Alertness to adapt the level of automation to the
task and/or circumstances or to revert to hand
flying / manual thrust control, if required; and,
•
Adherence to design philosophy, operating
philosophy and SOPs.
Briefing Notes Summary
Page 2
AIRBUS INDUSTRIE
Flight Operations Support
Getting to Grips with
Approach-and-Landing Accidents Reduction
1.3 - Operations Golden Rules
If only one lesson were to be learned from the
proposed set of Golden Rules, the following is
proposed:
The operations Golden Rules defined by Airbus
Industrie assist trainees in maintaining their basic
airmanship even as they progress to integrated and
automated aircraft models.
Whatever the prevailing conditions, always ensure
that one pilot is controlling and monitoring the flight
path of the aircraft.
General Golden Rules:
•
Automated aircraft can be flown like any
other aircraft;
1.4 - Standard Calls
•
Fly, Navigate, Communicate and Manage – in
that order;
Standard Calls ensure effective interaction and
communication between crewmembers and, thus,
enhance flight crew situational awareness.
•
One head up at all times;
•
Cross check the accuracy of the FMS with
raw data;
•
Know your FMA [guidance] at all times;
•
When things don’t go as expected, Take Over;
•
Use the correct level of automation for the
task; and,
•
Practice task sharing and back-up each other.
Golden Rules
Conditions:
for
Abnormal
and
Calls
/
Commands
and
Responses
/
Acknowledgements are of equal importance to
guarantee a timely action or correction.
The use of standard calls and acknowledgements
reduces the risk of tactical (short-term) decisionmaking errors (e.g., in arming or engaging AP/FD
modes, setting guidance targets or selecting aircraft
configurations).
Use of standard calls is of paramount importance
for optimum use of automation (i.e., awareness of
arming or engagement of modes, setting of targets,
lateral revision or vertical revision of FMS flight plan,
mode transitions, etc).
Emergency
•
Understand the prevailing condition before
acting;
•
Assess risks and time pressures;
•
Review and evaluate the available options;
•
Match the response to the situation;
•
Manage workload;
•
Create a shared problem model with other
crewmembers by communicating; and,
•
Apply recommended procedures and other
agreed actions.
When defining standard calls, standardization
(across fleets) and operational efficiency should be
carefully balanced.
1.5 - Normal Checklists
Initiating and completing normal checklists in a
timely manner is the most effective means of
preventing the omission of actions or preventing
inappropriate actions.
Explicit calls should be defined in the SOPs for the
interruption (hold) and resumption (continuation) of
a normal checklist (i.e., in case of interruption or
distraction).
Briefing Notes Summary
Page 3
AIRBUS INDUSTRIE
Flight Operations Support
Getting to Grips with
Approach-and-Landing Accidents Reduction
Disciplined use of normal checklists should be:
•
Robust standard operating procedures;
•
Highlighted at all stages of transition training,
line training and recurrent training; and,
•
Effective CRM practices; and,
•
•
Personal lines-of-defense.
Emphasized at the opportunity of all checks and
audits performed during line operation.
2.2 - CRM Issues in Approach-and-landing
Accidents
1.6 - Approach and Go-around Briefings
CRM issues are involved to some degree in every
incident or accident (e.g., non-adherence to
procedures, interaction with automated systems).
To ensure mutual understanding and effective
cooperation among crewmembers and with ATC, indepth approach and go-around briefings should be
conducted on each flight.
The minimum content of CRM training is defined by
regulations but airlines should consider additional
CRM training to account for specific requirements,
such as multi-cultural flight crews and/or different
areas of operation.
The approach and go-around briefings should be
adapted to the conditions of the flight and
concentrate on the items that are relevant for the
particular approach and landing (e.g., specific
approach hazards).
CRM practices optimize the performance of the
entire crew (i.e., including flight crew and cabin
crew, and maintenance personnel).
The approach and go-around briefings should
include the following ALAR-critical items:
•
Minimum safe altitude;
CRM skills contribute to:
•
Terrain and man-made obstacles features;
•
•
Relieve the effects of pressures, interruptions
and distractions;
Weather conditions;
•
Runway condition;
•
Provide benchmarks for timely decision-making;
and,
•
Other approach hazards (e.g., terrain, visual
illusions);
•
•
Applicable minimums (visibility or RVR, ceiling
as applicable);
Provide
safeguards
for
effective
error
management, thus minimizing the effects of
working errors.
•
Applicable stabilization height (approach gate);
•
Final approach flight path angle (and vertical
speed); and,
•
Go-around altitude and missed-approach initial
steps.
2.3 - Effective Pilot/Controller Communications
Achieving effective pilot/controller communications
requires a global approach; the importance of the
following key points should be emphasized:
•
Recognition and understanding of pilots’ and
controllers’ respective working environments
and constraints;
•
Disciplined use of standard phraseology;
•
Addressing Human Factors issues in approach-andlanding incidents and accidents is an effort that
must include:
Strict adherence to pilot / controller
communication loop: pilot’s feedback (readback)
/ controller’s confirmation (hearback );
•
Alertness to request clarification or confirmation,
when in doubt;
•
Defined company safety culture and policies;
•
•
Related accident-prevention strategies;
Readiness to question an incorrect clearance or
an inadequate instruction;
2 - Crew Coordination
2.1 - Human Factors in Approach-and-Landing
Accidents
Briefing Notes Summary
Page 4
AIRBUS INDUSTRIE
Flight Operations Support
Getting to Grips with
Approach-and-Landing Accidents Reduction
•
Preventing simultaneous transmissions;
3 - Altimeter and Altitude Issues
•
Adapting listening of party-line communications
as a function of the flight phase; and,
•
Adopting
clear,
concise
and
adapted
communications in an emergency situation.
3.1 - Altimeter Setting
Use of Radio Altimeter
Altimeter-setting errors result in a lack of vertical
situational awareness; the following should be
emphasized to minimize altimeter-setting errors and
to optimize the use of barometric-altimeter bug and
radio-altimeter DH:
2.4 - Intra-Cockpit Communications –
Managing Interruptions and Distractions
•
Awareness of altimeter setting changes with
prevailing weather conditions (extreme cold or
warm fronts, steep frontal surfaces, semipermanent or seasonal low pressure areas);
Interruptions and distractions usually result from the
following factors:
•
Awareness of the altimeter-setting unit in use at
the destination airport;
•
Pilot/controller or intra-cockpit communications
(including
flight
crew
/
cabin
crew
communications);
•
Awareness of the anticipated altimeter setting,
using two independent sources for cross-check
(e.g., METAR and ATIS messages);
•
Head-down work; or,
•
Effective PF/PNF cross-check and backup;
•
•
Adherence to SOPs for:
Responding to an abnormal condition or to an
unanticipated situation.
− reset of barometric-altimeters in climb and
descent;
Prevention strategies and lines-of-defense should
be developed to minimize interruptions and
distractions and to lessen their consequences.
− use of standby-altimeter to cross-check main
altimeters;
Strict adherence to the following standards is the
most effective prevention strategy:
− radio-altimeter callouts; and,
Omission of an action or an inappropriate action is
the most frequent causal factor in approach-andlanding accidents.
− altitude callouts;
− setting of barometric-altimeter bug and radioaltimeter DH.
•
SOPs;
•
Operations Golden Rules;
3.2 - Altitude deviations
•
Sterile-cockpit rule; and,
•
Recovery techniques, such as:
Altitude deviations may result in substantial loss of
vertical separation and/or horizontal separation,
which could cause a midair collision or CFIT.
− Identify – ask – decide – act; and,
An altitude awareness program should encourage
the blame-free reporting of altitude deviation events
to contribute to a better understanding of causal
factors and circumstantial factors involved in altitude
deviations.
− Prioritize – plan – verify.
Briefing Notes Summary
Page 5
AIRBUS INDUSTRIE
Flight Operations Support
Getting to Grips with
Approach-and-Landing Accidents Reduction
The following safeguards should be emphasized:
The following best practices should be promoted:
•
Adherence
to
the
pilot
/
controller
communication loop, i.e. readback / hearback
process;
•
Timeliness
preparation;
•
•
Strict adherence to SOPs for FMS setup;
Crew cross-check and backup to ensure that
the altitude selected (i.e., on the FCU) is the
assigned altitude (i.e., received from ATC);
•
Crosscheck of
crewmembers;
•
Cross-checking that the assigned altitude is
above the sector minimum safe altitude (unless
crew is aware of the applicable minimum
vectoring altitude for the sector);
•
Use of PFD, ND and FMS CDU to support and
illustrate the descent, approach and go-around
briefings;
•
Confirmation of FMS navigation accuracy,
before defining the use of automation for the
descent and approach (i.e., FMS modes or
selected modes);
•
Review of terrain awareness data and other
approach hazards; and,
•
Use of typical guidelines for descent-profile
planning, monitoring and adjustment.
•
Monitoring instruments and automation when
reaching the assigned altitude or FL; and,
•
In VMC, applying the technique one head inside
/ one head out when approaching the cleared
altitude or FL.
Altitude deviations should be prevented by strict
adherence to adequate SOPs for:
•
Selecting the assigned / cleared altitude or FL
on FCU; and,
•
Altitude callouts.
descent
all
data
and
entries
approach
by
both
4.2 - Energy Management during Approach
Setting the altimeter-reference on barometric
altimeters;
•
of
Inability to assess or manage the aircraft energy
level during the approach often is cited as a cause
of unstabilized approaches.
Either a deficit of energy (being low and/or slow) or
an excess of energy (being high and/or fast) may
result in approach-and-landing accidents, such as:
4 - Descent and Approach Management
•
Loss of control;
•
Landing short;
4.1 - Descent and Approach Profile
Management
•
Hard landing;
•
Tail strike;
Inadequate management of descent-and-approach
profile and/or incorrect management of aircraft
energy level during approach may result in:
•
Runway excursion; and/or,
•
Runway overrun.
•
Loss of vertical situational awareness; and/or,
•
Rushed and unstabilized approaches.
A deceleration below the final approach speed
should be accepted only in the following cases:
Either situation increases the risk of approach-andlanding accidents, including those involving a CFIT.
•
GPWS/TAWS terrain avoidance maneuver;
•
Collision avoidance maneuver; and,
•
Wind shear recovery and escape procedure.
Briefing Notes Summary
Page 6
AIRBUS INDUSTRIE
Flight Operations Support
Getting to Grips with
Approach-and-Landing Accidents Reduction
Nevertheless, in all three cases, the thrust levers
must be advanced to the maximum thrust (i.e., goaround thrust) while initiating the maneuver.
When and how to build and maintain terrain
awareness ?
5 - Approach Hazards Awareness
The following recommendations and guidelines
should be used to develop company strategies and
actions enhancing terrain awareness:
5.1 - Approach Hazards Awareness - General
Approach charts
A company awareness program on approach-andlanding hazards should review and discuss the
following factors that may contribute to approachand-landing accidents:
Providing flight crews with departure and approach
charts featuring terrain with color-shaded contours.
Altimeter-setting procedures
•
Flight crew fatigue;
•
Type of approach;
•
Approach charts;
•
Airport information services;
Flight progress monitoring
•
Airport air traffic control services;
•
Airport equipment;
The following
emphasized:
•
Terrain and man-made obstacles;
•
•
Monitoring and cross-checking FMS guidance
and navigation accuracy;
Visual illusions;
•
•
Monitoring instruments and navaids raw data;
Visibility;
•
•
Wind conditions;
Using all available information available (cockpit
displays, navaids raw data and charts); and,
•
Runway condition;
•
•
Runway and taxiways markings;
Requesting confirmation or clarification from
ATC if any doubt exists about terrain clearance,
particularly when under radar vectors.
•
Low temperature operation; and,
•
Bird-strike hazards.
See 3.1 – Altimeter setting – Use of radio
Altimeter.
best
practices
need
to
be
Approach and go-around briefings
Approach and go-around briefings should include
terrain-awareness-critical items.
Flight crews should be aware of the compounding
nature of these hazards during approach and
landing.
See 1.6 – Approach and Go-around Briefings.
5.2 - Terrain Awareness
Preparedness and commitment for go-around
Terrain awareness is defined as the combined
awareness and knowledge of:
•
Aircraft position;
•
Aircraft altitude;
•
Applicable minimum safe altitude (MSA);
•
Terrain location and features; and,
•
Other hazards.
Go-around is not a frequent occurrence; SOPs
should stress the importance of being:
•
Committed for an immediate response to
(E)GPWS / TAWS warnings.
•
Prepared and minded for a go-around, when
warranted.
See 6.1 – Being Prepared for Go-around.
Briefing Notes Summary
Page 7
AIRBUS INDUSTRIE
Flight Operations Support
Getting to Grips with
Approach-and-Landing Accidents Reduction
− monitoring by PNF of headdown cues for
effective cross-check and backup (e.g., for
calling any excessive-parameter-deviation).
Crew coordination, cross-check and backup
The following elements of an effective cross-check
and back up should be promoted to enhance terrain
awareness:
•
Altitude calls;
•
Excessive-parameter-deviation callouts;
•
Task sharing and standard calls for acquisition
of visual references; and,
•
Concept of pilot monitoring to define the role of
the pilot-not-flying (PNF) in hazards conditions.
5.4 - Windshear Awareness
Flight crew awareness and alertness are key factors
in the successful application of wind shear
avoidance and recovery techniques.
The following recommendations can be used for the
development of company initiatives enhancing wind
shear awareness.
Avoidance, Recognition and Recovery / Escape are
the main domains involved in effective wind shear
awareness:
Awareness of other approach hazards
•
See 5.1 – Approach Hazards Awareness – General
and 5.3 – Visual Illusions Awareness.
Avoidance:
−
Assessing conditions for a safe takeoff or
approach-and-landing,
based
on
all
available meteorological data, visual
observations and on-board equipment;
−
Delaying takeoff or approach, or diverting to
a more suitable airport; and,
−
Being prepared and committed for an
immediate response to a predictive or
reactive wind shear warning.
5.3 - Visual Illusions Awareness
Visual illusions take place when conditions modify
the pilot’s perception of the environment relative to
his/her expectations.
Visual illusions may result in landing short, hard
landing or runway overrun, but may also result in
spatial disorientation and loss of control.
•
The following key points need to be emphasized:
•
Awareness of weather factors;
•
Awareness of surrounding terrain and obstacles;
•
Awareness and assessment of approach
hazards (i.e., conditions that may cause visual
illusions, such as “black hole”);
•
•
Adherence to defined PF/PNF task sharing for
acquisition of visual references and for flying the
visual segment, this includes:
− monitoring by PF of outside visual cues while
transiently referring to instruments to support
and monitor the flight path during the visual
segment; and,
Recognition:
−
Being alert to recognize potential or existing
wind shear conditions, based on all
available weather data, on-board equipment
and monitoring of aircraft flight parameters
and flight path; and,
−
Enhancing instrument scan, whenever
potential wind shear is suspected.
Recovery / Escape:
−
Avoiding large thrust variations or trim
changes in response to sudden airspeed
variations;
−
Following FD wind shear recovery and
escape
guidance
or
applying
the
recommended FCOM (AOM) recovery and
escape procedure; and,
−
Making maximum use of aircraft equipment
(e.g., flight path vector, as available).
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Strict adherence to defined PF / PNF task sharing
and optimum use of crew resources management
are of paramount importance during a go-around.
(e.g., for monitoring and callout of any flight
parameter excessive-deviation)
6 - Readiness and Commitment to
Go-around
6.1 - Being Prepared to Go-around
The manual go-around technique must:
Failure to recognize the need for and/or to execute
a
go-around
and
missed-approach,
when
appropriate, is a major cause of approach-andlanding accidents.
•
Minimize the initial altitude loss;
•
Prevent an excessive pitch attitude by :
More than 70 % of approach-and-landing accidents
contained elements which should have been
recognized by the crew as improper and which
should have prompted a go-around.
− following FD pitch commands ( SRS orders ),
not exceeding 18-degrees pitch attitude;
− considering a 25-degree pitch attitude as an
ultimate barrier from which the pilot should
return immediately.
Because a go-around is not a frequent occurrence,
the importance of being go-around-prepared and
go-around-minded should be emphasized.
If any warning is activated or if any other abnormal
condition occurs:
If the criteria for a safe continuation of the approach
are not met, the crew should initiate a go-around
and fly the published missed-approach.
6.2 - Flying a Manual Go-around
•
PF must concentrate his/her attention on flying
the aircraft (i.e., controlling and monitoring the
vertical flight path and lateral flight path); and,
•
PNF must analyze the abnormal condition and
perform the required actions, as per applicable
task sharing and ECAM and/or QRH
procedures.
A safe go-around should prioritize the elements of
the following 3-Ps rule :
•
Pitch :
6.3 - Terrain Avoidance ( Pull-up ) Maneuver
− Establishing and maintaining the target pitch
attitude;
•
CFIT events account for approximately 45 % of all
approach-and-landing accidents and are the leading
cause of fatalities.
Power :
− Setting go-around thrust and checking that
the required thrust is achieved; and,
•
Performance :
A typical awareness and training program for the
reduction of controlled-flight-into-terrain (CFIT)
should:
−
Confirming aircraft performance:
•
Educate pilots on factors that may cause CFIT;
! positive rate of climb;
•
Ensure that horizontal and vertical situational
awareness are maintained at all times;
•
Ensure that pilots achieve proficiency in the
execution of procedures and techniques
recommended for each type of approach;
•
Provide pilots with an adequate knowledge of the
capability and limitations of GPWS or EGPWS /
TAWS equipment installed on their aircraft; and,
! gear up;
! speed at or above V APP (V LS);
! speed brakes retracted;
! flaps as required;
! radio-altimeter
and
baro-altimeter
indications increasing; and,
! wings-level.
Briefing Notes Summary
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7 - Approach Techniques
Ensure that pilots are proficient in performing the
terrain avoidance maneuver required in response
to a GPWS or EGPWS / TAWS warning (as
published in the applicable FCOM and QRH).
7.1 - Flying Stabilized Approaches
Rushed and unstabilized approaches are the largest
contributory factor in CFIT and other approach-andlanding accidents.
The following key points should be highlighted when
discussing CFIT awareness and response to
(E)GPWS / TAWS warnings:
•
•
Response by PF must be immediate;
•
PNF must monitor and call the radio altitude and
altitude trend throughout the terrain avoidance
maneuver; and,
•
Rushed approaches result in insufficient time for the
flight crew to correctly:
Preventive actions should be (ideally) taken
before (E)GPWS / TAWS warning;
•
Plan;
•
Prepare; and,
•
Execute a safe approach.
The following defines the elements of a stabilized
approach:
Pullup maneuver must be continued at maximum
climb performance until warning has ceased and
terrain is cleared (i.e., as indicated by a steadily
increasing radio-altimeter reading).
6.4 - Bounce Recovery – Rejected Landing
•
The aircraft is on the correct lateral flight path
and vertical flight path (based on navaids
guidance or visual references);
•
Only small changes in heading and pitch are
required to maintain this flight path;
•
A rejected landing is defined as a go-around
maneuver initiated after touchdown of the main
landing gear or after bouncing.
The aircraft
configuration;
•
A rejected landing is a challenging maneuver,
decided and conducted in an unanticipated and
unprepared manner.
The power is stabilized and the aircraft is
trimmed to maintain the target final approach
speed on the desired glide path;
•
The landing checklist has been accomplished
as well as any required specific briefing; and,
•
No flight parameter exceeds the
applicable for the type of approach;
The SOPs should define the respective decision
criteria for:
•
Full-stop landing; or,
•
Rejected landing and go-around.
is
in
the
desired
landing
limits
These limits also define the criteria for flightparameters excessive-deviation callouts.
Three essential parameters need to be stabilized for
a safe final approach (including the visual segment):
Procedures and techniques should be published for
bounce recovery, including:
•
Aircraft track;
•
•
Flight path angle; and,
Continued landing; or,
•
Airspeed.
•
Rejected landing (i.e., go-around).
Depending on the type of approach and aircraft
equipment, the most appropriate level of automation
and available visual cues should be used to achieve
and monitor the stabilization of the aircraft.
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When transitioning to visual references, the pilot’s
perception of the runway and outside environment
should be kept constant by maintaining the:
•
•
•
Drift correction, to continue tracking the runway
centerline (i.e., resisting the tendency to
prematurely align the aircraft with the runway
centerline);
•
Acquisition of visual references and decision;
•
Not descending below the MDA(H) before
reaching the visual descent/decision point
(VDP); and,
•
Preparedness for go-around.
7.3 - Acquisition of Visual References
Aiming point, to remain on the correct flight path
until the flare height (i.e., resisting the tendency
to move the aiming point closer and, thus,
descend below the desired glide path / “duckunder”); and,
The transition from instrument references to visual
references is an important element of any type of
instrument approach.
Variations exist in airline operating philosophies
about PF-PNF task sharing for:
Final approach speed and ground speed, to
maintain the aircraft energy level.
7.2 - Flying Constant-Angle non-Precision
Approaches
Almost 60 % of CFIT incidents and accidents occur
during step-down non-precision approaches.
•
Acquisition of visual references;
•
Conduct of landing; and,
•
Conduct of go-around.
Task sharing for the acquisition of visual references
depends on:
The
constant-angle
non-precision
approach
technique (or CANPA) should be implemented and
trained worldwide for preventing CFIT and other
approach-and-landing accidents.
•
The type of approach (i.e., on the time available
for the acquisition of visual references); and,
•
The use of automation (i.e., on the level of
automation and redundancy).
The following aspects need to be stressed:
•
Criteria for determining the type of guidance to
be used;
•
FMS preparation, as applicable;
•
Completeness of approach briefing;
•
Planning of aircraft configuration setup;
•
Descent monitoring;
•
Energy management during initial approach,
intermediate approach and final approach;
•
Not descending below an
reaching the associated fix;
•
Determining the correct flight path angle and
vertical speed for the final descent segment;
•
Commencing the descent at the exact point;
•
Accepting an ATC request for a visual approach or
requesting a visual approach should be carefully
balanced against the following decision criteria:
Maintaining the correct flight path angle (or
vertical speed) during the final descent
(including the visual segment);
•
Ceiling and visibility conditions;
•
Darkness;
altitude
The Airbus Industrie operating philosophy and
training philosophy promote a PF-PNF task sharing,
with acquisition of visual references by:
•
PNF, for non-precision approaches and CAT I
ILS approaches; and,
•
PF, for CAT II / CAT III ILS approaches.
For CAT II / CAT III operations, the CAPT usually is
the PF and only an automatic approach and landing
is considered.
before
7.4 - Flying Visual Approaches
Briefing Notes Summary
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Weather:
−
wind, turbulence;
− rain showers; and/or,
•
Performing altitude and excessive-parametersdeviation callouts; and,
•
Complying with go-around
instrument approaches.
policy,
as
for
− fog or smoke patches;
•
Crew experience
environment:
with
airport
and
8 - Landing Techniques
airport
8.1 - Preventing Runway Excursions and
Overruns
− surrounding terrain; and/or,
− specific airport
(obstructions, …);
•
and
runway
hazards
Runway excursions and runway overruns account
respectively for 8 % and 12 % of all approach-andlanding accidents.
Runway visual aids:
− Type of approach lighting system; and,
Runway excursions and runway overruns can be
categorized into six families of events, depending on
their primary causal factor, as follows:
− Availability of a VASI or PAPI.
The following key points should be discussed during
flight crew training for safe visual approaches:
•
Events resulting from an unstabilized approach;
•
Event resulting
technique;
•
Events resulting from unanticipated or moresevere-than-expected
adverse
weather
conditions (e.g., tail wind, crosswind or wind
shear);
from
an
incorrect
flare
•
Assessing the company
operating environment);
•
Developing company prevention strategies and
personal lines-of-defense.
•
Weighing the time saved against the possible
risk;
•
•
Awareness of and accounting for weather
factors;
Events resulting from reduced or loss of braking
efficiency;
•
•
Awareness of surrounding terrain and obstacles;
Events
resulting
from
configuration, including:
•
Awareness of airport environment, airport and
runway hazards;
•
Use of a published visual approach chart or use
of a visual circuit pattern;
•
Tuning and monitoring all available navaids;
•
Use of automation with timely reversion to hand
flying;
•
Adherence to defined PF/PNF task sharing:
exposure
(i.e.,
•
abnormal
−
aircraft dispatch under minimum equipment
list [MEL] / dispatch deviation guide [DDG];
or,
−
in-flight malfunction; and,
Events resulting from incorrect crew action or
inadequate crew coordination, under adverse
technical or weather conditions.
Company prevention strategies and individual linesof-defense should be developed based on:
− PF should fly the aircraft and look outside
(i.e., being head up); while,
− PNF should monitor instruments (i.e., being
head down);
•
an
Maintaining visual contact with runway and other
traffic at all times;
•
Strict adherence to SOPs;
•
Enhanced awareness of environmental factors;
•
Enhanced
understanding
of
aircraft
performance and handling techniques; and,
Briefing Notes Summary
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8.4 - Optimum Use of Braking Devices
Enhanced alertness for:
−
flight-parameters monitoring:
−
excessive-deviation callouts; and,
To ensure an optimum use of braking devices, the
following aspects must be understood:
−
mutual cross-check and back-up.
•
Design and operation of each braking device;
•
Distribution of stopping forces during landing
roll;
•
Type of braking required to achieve the desired
stopping distance;
•
Factors affecting the optimum use of braking
devices; and,
•
Applicable operational guidelines.
8.2 - The Final Approach Speed
Assuring a safe landing requires achieving a
balanced distribution of safety margins between:
•
The computed final approach speed ; and,
•
The resulting landing distance.
The applicable FCOM and QRH provide:
Adhering to the following operational guidelines
ensures an optimum braking during the landing roll:
•
Reference approach speeds; and,
•
Speed corrections applicable for various
operational factors and aircraft configurations.
•
Arming ground spoilers;
•
Arming autobrake with the most appropriate
mode for prevailing conditions (e.g., short
runway, low visibility, contaminated runway);
•
Selecting thrust reversers as soon as possible
with maximum reverse thrust (this increases
safety on dry and wet runway, and is mandatory
on runway contaminated with standing water,
slush, snow or ice);
•
Monitoring
extension;
•
Monitoring and calling autobrake operation;
•
Being ready to take over from autobrake,
if required;
8.3 - Factors Affecting Landing Distance
Understanding factors affecting landing distance
contributes to preventing runway overrun events.
When assessing the landing distance for a given
landing, the following factors should be accounted
for, and combined as specified in the applicable
FCOM / QRH:
•
Dispatch conditions, as applicable (dispatch
under minimum equipment list [MEL] / dispatch
deviation guide [DDG] );
and
calling
ground
spoilers
•
In-flight failures, as applicable;
•
Weather conditions (e.g., icing conditions/ice
accretion);
•
•
Monitoring engine operation in reverse thrust
(e.g., increasing EGT, evidence of surge);
Wind conditions (i.e., wind component and gust,
suspected wind shear);
•
Monitoring airspeed indication and returning
reverse levers to the reverse idle position at the
published indicated airspeed or when airspeed
fluctuations occur, whichever come first;
•
If required, using maximum pedal braking; and,
•
Maintaining braking action until assured that the
aircraft will stop within the remaining runway
length.
•
Airfield elevation;
•
Runway slope (if down hill);
•
Runway condition
contaminant); and,
•
Use of braking devices (thrust reversers,
autobrake).
(nature
and
depth
of
Briefing Notes Summary
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8.5 - Landing on Wet or Contaminated Runway
Factors associated with landing on a wet runway or
on a runway contaminated with standing water,
slush, snow or ice should be assessed carefully
before beginning the approach.
•
Monitoring operation of autobrake (on
contaminated runway, the selected deceleration
rate may not be achieved, therefore the light
indicating that the selected deceleration rate is
achieved may not illuminate);
•
Lowering the nose landing gear without undue
delay to:
The following operational recommendations need to
be emphasized:
•
•
Diversion to an airport with better runway
conditions and/or less crosswind component,
when actual conditions significantly differ from
forecast conditions or in case of system
malfunction;
Anticipating asymmetry effects that would
prevent efficient braking or directional control
(e.g.,
crosswind,
single-thrust-reverser
operation);
•
Avoiding landing on a contaminated runway
without antiskid or with a single thrust reverser;
•
For inoperative items affecting the braking or lift
dumping capability, referring to the applicable:
•
−
FCOM and QRH, for in-flight malfunctions,
or,
−
Minimum Equipment List (MEL) or Dispatch
Deviation Guide (DDG), for known dispatch
conditions;
•
Aiming for the touchdown zone;
•
Performing a firm touchdown (to prevent
hydroplaning and ensure rotation of main
landing gear wheels);
•
Using maximum reverse thrust as soon as
possible after touchdown (as thrust reverser
efficiency is higher at high speed);
•
−
activate systems associated with nose
landing gear switches (e.g., anti-skid
reference speed);
•
As required, or when taking over from
autobrake, applying brakes normally with a
steady pressure;
•
For directional control, using rudder pedals and
differential braking, as required (i.e., not using
nose-wheel-steering tiller);
•
If differential braking is necessary, applying
pedal braking on the required side and releasing
completely the pedal action on the opposite
side; and,
•
After reaching taxi speed, using nose-wheelsteering with care.
Several sources of wind information are available to
the flight crew:
On contaminated runway, use of a medium
setting usually is recommended to assure
immediate braking action after touchdown (i.e.,
without time delay);
Approaching on glide path and at the target final
approach speed;
increase the weight-on-wheels and, thus,
increase the braking efficiency; and,
8.6 – Use of Wind Information
Selecting autobrake with a medium or low
setting, if the contaminant is evenly distributed;
•
−
•
ATC (i.e., METAR, ATIS and tower winds); and,
•
Aircraft systems (i.e., IRS and FMS winds).
Each wind information must be understood for
appropriate use during various flight phases.
The following facts and figures should be recalled:
•
The METAR wind is a 10-minute average wind;
•
The ATIS or tower average wind is a 2-minute
average wind;
•
The ATIS or tower gust is the wind peak value
during the last 10-minute period;
Confirming the extension of ground spoilers;
Briefing Notes Summary
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The ATIS message is updated only if the wind
direction changes by more than 30 degrees or if
the wind velocity changes by more than 5 kt
over a 5-minute time period;
Adherence to the following key points increases
safety during crosswind-landing operations:
•
Understanding applicable operating factors,
maximum recommended values and limitations;
If an instantaneous wind reading is desired and
requested from the ATC, the phraseology
“instant-wind“ should be used in the request
(some controllers may provide such instant-wind
without request under shifting and/or gusting
wind conditions);
•
Using recommended and published flying
techniques associated with crosswind landing;
•
The IRS wind is a near-real-time wind;
•
The FMS wind is a 30-second-average wind;
and,
•
Note :
A wings-level touchdown (i.e., without any
decrab) may be safer than a steady-sideslip
touchdown with an excessive bank angle;
•
The
maximum
demonstrated
crosswind
generally applies to a steady wind and is not a
limitation (unless otherwise stated).
Requesting the assignment of a more favorable
runway, if prevailing runway conditions and
crosswind
component
are
considered
inadequate for a safe landing;
•
Flight crews should use the most appropriate source
of wind information, depending on the flight phase
and intended use.
Adapting the autopilot disconnect altitude to
prevailing conditions in order to have time to
establish manual control and trim the aircraft
before the align/decrab phase and flare;
•
Being alert to detect changes in ATIS and tower
messages (wind direction shift, velocity and/or
gust increase); and,
•
Being aware of small-scale
associated with strong winds:
8.7 - Crosswind Landing
Operations in crosswind conditions require strict
adherence to applicable limitations or maximum
recommended crosswind values, operational
recommendations
and
handling
techniques,
particularly when operating on wet or contaminated
runways.
Align the aircraft with the runway centerline,
while preventing drifting sideways, by applying
into-wind aileron and opposite rudder (i.e., using
cross-controls);
•
Perform a partial decrab, using the crosscontrols technique to continue tracking the
runway centerline; or,
•
Maintain the crab angle, for drift correction, and
wings-level until the main landing gear
touchdown.
effects
−
Updrafts and downdrafts;
−
Vortices created by buildings, forests or
terrain.
Approach-and-Landing Briefing Notes
Approaching the flare point with wings-level and a
crab angle, as required for drift correction, three
flare techniques are possible (depending on runway
condition, crosswind component and company
SOPs):
•
local
The scope, structure and suggested use of the
Approach-and-Landing Briefing Notes are described
in the chapter Introducing the Briefing Notes.
Briefing Notes Summary
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Approach-and-Landing Reduction Task Force
Conclusions and Recommendations
The flight segment from the outer marker to the
completion of the landing roll represents only 4 % of
the flight time but 45 % of hull losses.
Introduction
This summary presents the conclusions and
recommendations of the international Approachand-Landing Accident Reduction (ALAR) Task
Force led by the Flight Safety Foundation (FSF).
These statistical data have not shown any down
trend over the past 40 years.
Five types of events account for 75 % of approachand-landing incidents and accidents:
Background
The FSF ALAR Task Force was created in 1996 as
another phase of the Controlled Flight Into Terrain
(CFIT) accident reduction program launched in the
early 1990s.
The FSF ALAR Task Force collected and analyzed
data related to a significant set of approach-andlanding accidents, including those resulting in
controlled-flight-into-terrain CFIT).
Air Traffic Control - Training and Procedures;
•
Airport Facilities;
•
Aircraft equipment; and,
•
Aircraft Operations and Training.
CFIT (including landing short of runway);
•
Loss of control;
•
Runway overrun;
•
Runway excursion; and,
•
Unstabilized approaches.
Implementation
The Task Force developed conclusions and
recommendations for practices that would improve
safety in approach-and-landing, in the following
domains:
•
•
The conclusions and recommendations of the ALAR
Task Force need to be translated into industry
actions to ensure their effective implementation.
The Flight Safety Foundation is committed to a
significant awareness campaign that will ensure
availability of this information to everyone who
participates in approach-and-landing operations, so
that all can play a part in improving safety within
their sphere of influence.
The cooperation and contribution of all players in the
global aviation system are required to:
All conclusions and recommendations were datadriven and supported by factual evidence of their
relevance to the reduction of approach-and-landing
incidents and accidents.
•
Enhance
partnership,
communication between:
cooperation
−
operators;
Statistical Data
−
air traffic control services;
Approach-and-landing accidents (defined as
accidents occurring during the initial approach, final
approach and landing) represent approximately
55 % of total hull losses and 50 % of fatalities.
−
state operational authorities;
−
state navigation agencies;
−
services providers;
Flight Safety Foundation ALAR Task Force – Conclusions and Recommendations
Page 1
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AIRBUS INDUSTRIE
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•
•
−
training organizations; and,
−
manufacturers.
Getting to Grips with
Approach-and-Landing Accidents Reduction
•
Errors in using and managing the automatic
flight system and/or the lack of awareness of the
operating modes are causal factors in more
than 20 % of approach-and-landing accidents;
and,
Achieve a wide dissemination of the ALAR
Education and Training Aid (ALAR Tool Kit),
including:
−
ALAR awareness video;
−
Briefing Notes;
−
Safety Alert Bulletins;
−
Risk Awareness Tool (checklist);
−
Risk Reduction Planning Guide; and,
−
CFIT awareness presentation.
Operators should develop SOPs regarding the
use of automation during the approach and
landing phases and provide training accordingly;
•
Operators should define a clear policy regarding
the role of the pilot-in-command (commander) in
complex and demanding situations;
Training should address the practice of
transferring flying duties during operationally
complex situations.
Flightcrew Decision-Making:
Facilitate an easy and fast implementation of all
conclusions and recommendations.
Conclusions:
Establishing and adhering to adequate decisionmaking processes improve approach and landing
safety.
Operations and Training Overview
Standard Operating Procedures (SOPs):
Crew resource management issues, including
decision-making under stress, are observed as
circumstantial factors in more than 70 % of
approach-and-landing accidents.
Conclusions:
Establishing and adhering to adequate standard
operating procedures (SOPs) improves approach
and landing safety.
Recommendations;
The omission of an action or an inappropriate action
rank:
•
As a causal factor, along with other factors, in
45 % of fatal approach-and-landing events; and,
•
A factor, to some degree, in 70 % of all
approach-and-landing accidents.
Recommendations:
•
•
Operators should provide education and training
that enhance flightcrew decision-making and
risk (error) management; and,
•
Operators should develop an effective tactical
decision-making model for use in time-critical
situations.
Preparedness to Go-around and Commitment
for Missed-Approach:
State should mandate and operators should
develop and implement SOPs for approach-and
-landing operations;
Conclusions:
Operators should develop SOPs that allow their
practical application in normal operating
environment;
Failure to recognize the need for and to execute a
missed approach when appropriate is a major
cause of approach and landing accidents.
The involvement of flight crews is essential in
the development and evaluation of SOPs;
•
•
More than 70 % of approach-and-landing accidents
contained elements which should have been
recognized by the crew as improper and which
should have prompted a go-around.
Operators should implement routine and critical
evaluation of SOPs to determine the need for
change;
Flight Safety Foundation ALAR Task Force – Conclusions and Recommendations
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It is also observed than when an unstable approach
warrants a go-around decision, less than 20 % of
flightcrews actually initiate a go-around.
Recommendations:
•
Recommendations:
•
Operators should specify well-defined go-around
gates for approach and landing operations.
−
Intended flight path;
Parameters should include:
−
Speed;
− Visibility minima required for the approach
and landing operation;
−
Power setting;
−
Attitude;
− Assessment at the final approach fix (FAF) or
outer marker (OM) of crew and aircraft
readiness for approach; and,
−
Sink rate;
−
Configuration; and,
−
Crew readiness.
− Minimum altitude at which the aircraft must
be stabilized;
•
•
All flights should be stabilized by 1000-ft (300m)
height above airfield elevation in instrument
meteorological conditions (IMC) and by 500-ft
(150m) above airfield elevation in visual
meteorological conditions (VMC).
•
The approach should be considered stabilized
only if:
Operators should develop and support
No-blame Go-around and Missed Approach
Policies;
A true no-blame go-around policy should
alleviate the reporting and justification
requirements following a go-around or diversion;
and,
•
Operators should define the parameters of a
stabilized approach in their flight operations
manuals (policy manual) and/or in their aircraft
operating manual (AOM), including at least the
following elements:
− The aircraft is on the correct flight path;
− Only small changes in heading and pitch are
required to maintain that path;
Training
and
company
performance
management systems should reinforce these
policies.
−
Flying Stabilized Approaches:
Conclusions:
The airspeed is:
!
not more than V APP + 10 kt IAS; and,
!
not less than V APP – 5 kt;
Note :
Unstabilized and rushed approaches contribute to
approach and landing accidents.
The above recommendation has been
adapted to reflect the Airbus V APP concept.
Continuing an unstabilized approach is a causal
factor in 40 % of all approach-and-landing
accidents.
− The aircraft is
configuration;
in
the
proper
landing
− The sink rate is not greater than 1 000 ft/mn;
Approximately 70 % of rushed and unstable
approaches involve an incorrect management of the
descent-and-approach profile and/or energy level
(i.e., being slow and/or low, being fast and/or high).
If an approach requires a sink rate greater
than 1 000 ft/mn, a special briefing is
required;
Flight Safety Foundation ALAR Task Force – Conclusions and Recommendations
Page 3
AIRBUS INDUSTRIE
Flight Operations Support
−
−
•
Getting to Grips with
Approach-and-Landing Accidents Reduction
Pilot / Controller Communications:
The power setting is appropriate for the
configuration and not below the minimum
power for approach, as defined in the aircraft
operating manual, as applicable; and,
Conclusions:
Improving
communication
and
mutual
understanding between air traffic control services
and flight crews of each other’s operational
environment will improve approach and landing
safety.
All briefings and checklists have been
performed; and,
In addition, LOC-only and ILS approaches are
considered stabilized if they also fulfill the
following:
−
−
−
Incorrect or inadequate:
LOC-only approaches must be flown within
one dot of the localizer;
CAT I ILS approaches must be flown within
one dot of the glide slope (GS) and localizer
(LOC); and,
•
During circling approaches, wings must be level
on final when the aircraft reaches 300 ft airfield
elevation;
•
Unique approaches may require a special
briefing;
•
Company policy (policy manual or SOPs) should
state that a go-around is required if the aircraft
becomes unstabilized during the approach;
•
The implementation of certified constant-angle
procedures for non-precision approaches should
be expedited globally;
•
•
•
•
Weather or traffic information; and/or,
•
Advice/service in case of emergency,
Approximately 70 % of altitude deviations are the
result of a breakdown in the controller / pilot
communication loop.
Note :
The above recommendation has been adapted
to reflect the Airbus LOC and GS excessive
deviation warnings.
During visual approaches, wings must be level
on final when the aircraft reaches 500 ft above
airfield elevation;
ATC instructions;
are causal factors in more than 30 % of approachand-landing accidents.
CAT II or CAT III ILS approaches must be
flown within the glide slope and localizer
excessive deviation warnings;
•
•
Recommendations:
ATC services and operators should:
•
Introduce joint training that involves both ATC
personnel and flight crews to:
− Promote mutual understanding of issues such
as procedures, instructions, operational
requirements and limitations between flight
deck and the ATC environment;
− Improve controllers’ knowledge of the
capabilities advanced technology flight decks;
and,
− Foster improved communications and task
management by pilots and controllers during
emergency situations; and,
•
Flight crews should be trained on the proper use
of
constant-angle,
stabilized
approach
procedures;
Ensure that controllers are aware of the
importance
of
unambiguous
information
exchange,
particularly
during
in-flight
emergencies;
•
Flight crews should be educated on the
approach design-criteria and minimum obstacleclearance requirements (i.e., for each segment
of the approach); and,
Implement procedures that require immediate
clarification or verification of transmissions from
flight crews that indicate a possible emergency
situation;
•
Implement procedures for ATC handling of
aircraft in emergency situations to minimize
flight crew distraction;
Flightcrews should “take time to make time”
whenever cockpit situation becomes confusing
or ambiguous.
Flight Safety Foundation ALAR Task Force – Conclusions and Recommendations
Page 4
AIRBUS INDUSTRIE
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Getting to Grips with
Approach-and-Landing Accidents Reduction
•
In cooperation with airport authorities and
rescue services, implement unambiguous
emergency
procedures
and
common
phraseology to eliminate confusion; and,
•
Develop, jointly with airport authorities and local
rescue services, emergency-training programs
that are conducted on a regular basis.
•
Operators should develop and implement a
policy for the appropriate use of automation,
navigation and approach aids for the approach
being flown.
Use of Radio Altimeter for Terrain Awareness:
Conclusions:
Flight crews should:
•
Verify
understanding
of
each
ATC
communication and request clarification when
necessary; and,
•
Accurately report the status of abnormal and
emergency situations and the need for
emergency
assistance
using
standard
phraseology.
Using the radio altimeter (RA) as an effective tool
helps prevent approach and landing accidents.
Recommendations:
Approach Hazards - Low Visibility, Visual
Illusions and Contaminated Runway Operations:
•
Education is needed to improve crew
awareness of radio altimeter operation and
benefits;
•
Operators should state that the radio altimeter is
to be used during approach operations and
specify procedures for its use; and,
•
Operators should fit radio altimeters and
activate “Smart Callouts” at 2,500 feet, 1,000
feet, 500 feet, at 200 feet or the altitude set in
the “DH” (decision height) window (as well as at
50 ft, 40 ft, 30ft, 20 ft and 10 ft, as required) for
enhanced terrain awareness.
Conclusions:
The risk of approach and landing accident is higher
in operations conducted in low light and/or visibility,
on wet or otherwise contaminated runways, and with
the presence of optical or physiological illusions.
More than 70 % of CFIT
excursion/overrun events occur:
and
runway
Flight Operations Quality Assurance (FOQA):
Conclusions:
•
In low visibility;
•
In hilly or mountainous terrain;
•
On contaminated runway; and/or,
•
Under adverse wind conditions.
Collection and analysis of in-flight parameters,
(FOQA) programs identify performance trends that
can be used to improve approach and landing
safety.
Recommendations:
The lack of acquisition or the loss of visual
references is the most common primary causal
factor in approach-and-landing accidents.
•
FOQA should be implemented worldwide in
tandem with information sharing partnerships
such as the Global Analysis and Information
Network (GAIN), the British Airways Information
System (BASIS) and the Aviation Safety Action
Partnership (ASAP);
•
Examples
of
FOQA
benefits
(safety
improvements and cost reduction) should be
publicized widely; and,
•
A process should be developed to bring FOQA
and information sharing partnerships to regional
and business aviation.
Recommendations:
•
•
Flight crews should be trained in operations
involving adverse conditions (i.e., crosswind,
runway contamination) before they are assigned
line duties;
Flight crews should make operational use of a
risk-assessment checklist to identify approach
and landing hazards;
Appropriate procedures should be implemented
to lessen these risks; and,
Flight Safety Foundation ALAR Task Force – Conclusions and Recommendations
Page 5
AIRBUS INDUSTRIE
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•
Aviation Information Sharing:
Conclusions:
Communication / Navigation / Surveillance
(CNS) equipment such as Controller/Pilot Data
Link Communication (CPDLC).
Global sharing of aviation information decreases the
risk of approach-and-landing accidents.
Reference Document
Recommendations:
•
De-identification of aviation information data
sources should be a cardinal rule in FOQA and
information sharing processes; and,
•
Public awareness of the importance of
information sharing must be heightened through
a coordinated effort.
The following Special FSF Report provides a
consolidated source of statistical data, definitions
and facts about approach-and-landing accidents,
including those involving CFIT:
Flight Safety Foundation
Flight Safety Digest
Killers in Aviation:
FSF Task Force Presents Facts
About Approach-and-landing and
Controlled-flight-into-terrain Accidents
Optimum Use of Current Technology/Equipment
Although the Task Force issued conclusions and
recommendations
for
future
technological
developments, operators should consider the
immediate benefit of existing technology and
equipment such as:
•
Terrain Awareness and Warning System
(TAWS) for better terrain awareness and early
warning;
•
Quick Access Recorder (QAR) and use Flight
Operations Quality Assurance (FOQA) to detect
and correct unsafe trends;
•
Radio altimeter with smart
enhanced terrain awareness;
•
Precision
approach
guidance
whenever
available and use of VASI/PAPI in support of
visual segment;
•
GPS-based lateral navigation and barometric
vertical navigation (pending the availability of
GPS Landing System [GLS] approaches
through the use of GNSS or GPS Local Area
Augmentation System (LAAS);
•
Mechanical or electronic checklists to improve
checklist compliance (particularly in case of
distraction or interruption);
•
Approach and airport familiarization programs
based on:
callouts
−
High-resolution paper material;
−
Video display; and/or
−
Simulator visual; and,
Volume 17/No 11-12 – Volume 18/No 1-2
Nov.-Dec.98/Jan.-Feb.99
for
Flight Safety Foundation ALAR Task Force – Conclusions and Recommendations
Page 6
AIRBUS INDUSTRIE
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Approach-and-Landing Accidents Reduction
Introducing the Briefing Notes
General
To support this strategy, each Briefing Note:
The set of Approach-and-Landing Briefing Notes
has been developed by Airbus Industrie in the frame
of the Approach-and-Landing Accidents Reduction
(ALAR) Task Force led by the Flight Safety
Foundation (FSF).
The Approach-and-Landing Briefing Notes provide
background
information,
operational
recommendations and training guidelines for the
implementation
of
the
conclusions
and
recommendations of the following international ALAR
working groups:
•
FSF ALAR Task Force; and,
•
U.S. Commercial Aviation Safety Team (CAST),
ALAR Joint Safety Implementation Team (JSIT).
Lessons-learned from operational analysis of inservice occurrences and from training feedback have
been also considered.
A generic version of the Approach-and-Landing
Briefing Notes is published by the FSF, for the
benefit of all global, regional and corporate operators,
in the Volume 19, No 8-11, Aug.-Nov./00 of the FSF
Flight Safety Digest.
•
Presents the subject in the CFIT and/or ALAR
context, using statistical data;
•
Emphasizes the applicable standards and best
practices (e.g., standard operating procedures
[SOPs], supplementary techniques, operational
recommendations and training guidelines);
•
Lists and discusses factors that may cause flight
crews to deviate from applicable standards, for
eye-opening purposes;
•
Provides or suggests company accidentprevention-strategies and/or personal lines-ofdefense, for prevention purposes and/or for
correction purposes;
•
Establishes a summary of operational key points
and training key points;
•
Refers to the assoc iated or related Briefing
Notes; and,
•
References related ICAO, U.S. FAR
European JAR regulatory documents.
and
The proposed education and training strategy is valid
at both company and personal level for:
Accident-Prevention Strategy
The Approach-and-Landing Briefing Notes have been
designed to allow an eye-opening and self-correcting
accident-prevention strategy.
•
Risk awareness (eye-opening);
•
Exposure assessment;
•
Identification of related prevention strategies
(at company level) and lines-of-defense
(at company and/or personal levels);
•
Analysis of flight data, line checks and line
audits; and,
•
Implementation of prevention strategies and/or
corrective actions.
Introducing the Briefing Notes
Page 1
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Defining a Reference Aircraft
How to Use and Implement the Briefing
Notes ?
The technical contents of the Approach-and-Landing
Briefing Notes refer to an aircraft defined to reflect the
design features common to most Airbus aircraft
families.
The Approach-and-Landing Briefing Notes should be
used by airlines to enhance the awareness of
approach-and-landing accidents, including those
resulting in CFIT, among flight crews and cabin
crews.
This reference aircraft features the following
equipment to allow discussing the role of each
system during the approach and landing:
•
Glass-cockpit, including an electronic flight
instrument system (EFIS) consisting of a primary
flight display (PFD) and navigation display (ND);
•
Integrated autopilot (AP) / flight director (FD) /
autothrottle/autothrust (A/THR) systems;
•
Flight management system (FMS);
•
Automatic ground-spoilers;
•
Autobrake system;
•
Thrust reversers;
•
Two flight -deck crewmembers ;
•
Operation using Airbus Industrie-published or
company-prepared
standard
operating
procedures (SOPs), defining the following
elements:
Management pilots should review, customize
(as
required)
and
implement
the
ALAR
recommendations,
guidelines
and
awareness
information, in the following domains:
•
Operational documentation:
− Standard operating procedures (e.g.,
incorporate ALAR-critical items); and,
to
− Procedures and techniques / Supplementary
techniques.
•
Training:
− Simulator Training, to develop new scenarios
for line oriented flight training (LOFT) or
special purpose operational training (SPOT);
and/or,
− Crew resource management (CRM) training,
to develop new topical subjects to support
CRM discussions.
−
Operating philosophy;
−
Use of automation;
−
Task sharing (for pilot flying [PF] and pilot non-flying [PNF] );
− Airline’s safety magazine articles;
−
PF and PNF tasks for all phases of ground
and flight operations;
− Classroom lectures (using Briefing Notes and
associated Presentations); and/or,
−
Briefings;
− Stand-alone reading.
−
Standard calls; and,
−
Normal checklists.
•
Information:
− Airline bulletins;
Line pilots should review and compare the
recommendations,
guidelines
and
awareness
information with their current practices and enhance
their techniques and awareness level, as required.
Introducing the Briefing Notes
Page 2
AIRBUS INDUSTRIE
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Other actors in the global aviation system, such as:
•
Airbus Cockpit Philosophy; and,
•
Air traffic control services;
•
Proceedings of:
•
Navigation state agencies;
−
Performance and Operations Conferences;
•
Operational authorities;
−
Human Factors Symposiums; and,
•
Service providers; and,
−
Operational Liaison Meetings.
•
Flight academies;
Aviation Regulations / Requirements:
should use the provision of the Briefing Notes to
evaluate their possible contribution to the reduction of
CFIT and Approach-and-Landing accidents.
•
ICAO – Annex 6 – Operation of Aircraft, Part I –
International Commercial Air Transport –
Aeroplanes;
•
ICAO – Procedures for Air Navigation Services
(PANS -OPS, Doc 8168);
Statistical data quoted in the Briefing Notes originate
from various industry sources.
•
European
Joint
JAR-OPS 1 –
(Aeroplanes);
The following Special FSF Report provides a
consolidated source of statistical data, definitions
and facts about approach-and-landing accidents,
including those involving CFIT:
•
U.S. FAR – Part 91 – Air Traffic and General
Operating Rules;
•
U.S. FAR – Part 121 – Operating Requirements:
Domestic, Flag, and Supplemental Operations;
and,
•
U.S. FAA – Aeronautical Information Manual
(AIM) – Basic Flight Information and ATC
Procedures.
Statistical Data
Flight Safety Foundation
Flight Safety Digest
Killers in Aviation:
Aviation
Requirement –
Commercial Air Transport
FSF Task Force Presents Facts
About Approach-and-landing and
Airlines’ Aircraft Operating Manuals:
Controlled-flight-into-terrain Accidents
•
Volume 17/No 11-12 – Volume 18/No 1-2
Nov.-Dec.98/Jan.-Feb.99
Several airlines’ aircraft operating manuals (AOM)
have been used to confirm operators’ best
practices
for
non-type-related
operational
matters.
Reference Documents
The following reference documents have been used to
support and illustrate the applicable standards,
operational recommendations and training guidelines:
The following references and data sources have been
used to document and analyze the operational
factors and human factors involved in approach-andlanding incidents and accidents:
Airbus
Industrie
documentation:
Government agencies web sites:
operational
and
training
•
NASA ASRS (http://ars.arc.nasa.gov/
http://human.factors.arc.nasa.gov/);
Quick Reference Handbooks (QRH);
•
U.S. FAA (http://www.faa.gov/);
•
Flight Crew Training Manuals (FCTM);
•
U.S. NTSB (http://www.ntsb.gov/aviation/);
•
Instructor Support Guides;
•
French BEA (http://www.bea-fr.org/);
•
Flight Crew Operating Manuals (FCOM);
•
Introducing the Briefing Notes
Page 3
and
AIRBUS INDUSTRIE
Flight Operations Support
Getting to Grips with
Approach-and-Landing Accidents Reduction
•
U.K. AAIB (http://open.gov.uk/aaib/); and,
•
Australian BASI (http://www.basi.gov.au/).
Acknowledgement
The following Airbus Industrie colleagues and
industry partners have contributed to this brochure in
reviewing the Briefing Notes in their respective fields
of expertise:
Airlines’ Flight Safety Magazines:
•
Air Canada;
•
Air France;
•
Air Inter;
•
American Airlines;
•
British Airways;
•
Cathay Pacific Airways; and,
•
US Airways.
Capt. Nagi ABSI, Fernando ALONSO, Capt. Michel
BRANDT,
Philippe
BURCIER,
Capt.
Dave
CARBAUGH, Capt. Alastair CRAIG, Capt. David
CURRY, Capt. Bertrand De COURVILLE, Guy
DI SANTO, Capt. Klaus FLADE, Capt. Dan
GURNEY, Jacky JOYE, Capt. Hans KREMMOLER,
Mark LACAGNINA, Robert LIGNEE, Capt. John
LONG, Capt. Dick Mc KINNEY, Christian MONTEIL,
Capt. Hugo PEREZ, Susan REED, Capt. Larry
ROCKLIFF, F/O Dan ROMERO, F/O Didier
RONCERAY, Roger ROZELLE, Capt. Gene
ROZENTHAL, Capt. Dick SLATTER, Jean Jacques
SPEYER, Capt. Rainer STARK, Capt. Christian
STIE, Capt. Robert SUMWALT, Capt. Etienne
TARNOWSKI.
Incidents and accidents analysis publications:
•
Avram Goldstein – Flying out of danger, A Pilot’s
Guide to Safety (Airguide Publications, Inc,
USA); and,
•
Macarthur Job – Air Disaster, Volumes 1,
Volume 2 and Volume 3 (Aerospace Publications
Pty Ltd, Australia).
Feature articles from the following publications:
•
Air Transport World;
•
AOPA Pilot;
•
Aviation Week and Space Technology;
•
Flight International;
•
FSF Flight Safety Digest;
•
FSF Accident Prevention Bulletins; and,
•
Professional Pilot.
Introducing the Briefing Notes
Page 4
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Approach-and-landing Briefing Notes
Glossary of Terms and Abbreviations
Term
or
Definition
Abbreviation
A/THR
AAL
AC
ACAS
Autothrottle or Autothrust system
Above Airport Level
U.S. FAA Advisory Circular
Airborne Collision Avoidance System ( see also TCAS )
ACP
Audio Control Panel ( see also DCDU )
ADC
Air Data Computer
AFE
Above Field Elevation
AFL
Above Field Level ( e.g., 1000 ft - height AFL )
AFM
Airplane Flight Manual ( approved by certification authorities )
AFS
Automatic Flight System, this includes the flight director (FD), the autopilot (AP),
the autothrottle/autothrust system (A/THR) and the flight management system (FMS)
AGL
Above Ground Level ( e.g., 1000 ft - height AGL, indicated by the radio altimeter or
computed by subtracting the terrain elevation from the altitude above MSL )
AIM
U.S. FAA Aeronautical Information Manual
( previously called Airman Information Manual )
Glossary of terms and Abbreviations
Page 1
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Term
or
Abbreviation
AIP
Definition
Aeronautical Information Publications
( published by ICAO member states )
ALA
ALAR
Approach-and-Landing Accident
Approach-and-Landing Accident Reduction
ALS
Airport Lighting System
ALTN
Alternate
AMC
Acceptable Means of Compliance ( for compliance with JAR-OPS 1 )
AOM
Aircraft Operating Manual ( established by operator )
AP
APP
Approach Gate
Auto Pilot
Approach control frequency
A point in space with a defined configuration and energy state
( see also Stabilization Height and Next Target )
ARTCC
ASAP
Air Route Traffic Control Center ( usually referred to as "Center" )
Aviation Safety Action Partnership
ATC
Air Traffic Control
ATIS
Automatic Terminal Information Service
ATM
Air Traffic Management
( one of the two components of FANS, see also FANS and CNS )
BASIS
BRG
British Airways Information System
Bearing ( e.g., bearing to a waypoint or navaid )
Glossary of terms and Abbreviations
Page 2
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Term
or
Abbreviation
Definition
CAP
U.K. Civil Aviation Publication
CAPT
Captain ( see also PIC )
CAST
Commercial Aviation Safety Team
( international industry task force led by U.S. FAA )
Causal Factor
CAWS
A causal factor is an event or item judged to be directly instrumental in the causal
chain of events leading to an accident ( source: Flight safety Foundation )
Collision Avoidance Warning System ( see TCAS )
CDU
Control and Display Unit ( see also MCDU )
CFIT
Controlled Flight Into Terrain
Checklist
See also QRH
Circumstantial Factor A circumstantial factor is an event or an item that was judged not to be directly in
the causal chain of events [ leading to an accident ] but could have contributed to
the accident ( source: Flight Safety Foundation )
CNS
Communication, Navigation and Surveillance
( one of the two components of FANS, see also FANS and ATM )
CONF
Configuration ( e.g., slats, flaps, roll spoilers, ground spoilers, ... )
CORR
Correction ( e.g., wind or configuration correction on final approach speed )
CPDLC
Controller Pilot Data Link Communications
CRM
Crew Resource Management
DA(H)
Decision Altitude ( Height )
DCDU
Data Communications Display Unit
Glossary of terms and Abbreviations
Page 3
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Term
or
Abbreviation
DDG
DIR TO
Definition
Dispatch Deviation Guide ( see also MMEL and MEL )
Direct route to [ a waypoint ]
DIST
Distance
DME
Distance Measuring Equipment
DNA
French Direction de la Navigation Aerienne
ECAM
Electronic Centralized Aircraft Monitor
EFIS
Electronic Flight Instruments System
EGPWS
Enhanced Ground Proximity Warning System ( see also TAWS )
EGT
Exhaust Gas Temperature
ETOPS
Extended Twins Operations
F/O
First Officer
FAA
U.S. Federal Aviation Administration
FAF
Final Approach Fix
FANS
Future Air Navigation System ( see also CNS and ATM )
FAR
U.S. Federal Aviation Regulations
FBS
Fixed Base Simulator
FCOM
Flight Crew Operating Manual ( established by Airbus Industrie )
FCU
Flight Control Unit ( i.e., AP/FD interface )
FD
Flight Director
Glossary of terms and Abbreviations
Page 4
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Term
or
Abbreviation
FDF
FFCC
Definition
Final Descent Fix
Forward-Facing-Crew Cockpit
FFS
Full Flight Simulator
FIR
Flight Information Region
FL
Flight Level
FMGS
FMA
FMGES
FMS
FOQA
FSF
ft
GA
Flight Management and Guidance System
Flight Modes Annunciator
Flight Management, Guidance and [flight] Envelop [protection] System
Flight Management System
Flight Operations Quality Assurance
Flight Safety Foundation
Feet
Go Around
GAIN
Global Analysis and Information Network
GCAS
Ground Collision Avoidance System
GND
GNSS
GPS
GPWS
Ground control frequency
Global Navigation Satellite System
Global Positioning System
Ground Proximity Warning System
Glossary of terms and Abbreviations
Page 5
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Term
or
Abbreviation
Definition
GS
Glide Slope
GW
Gross Weight
HAT
Height Above Touchdown
HF
High Frequency
HIRL
High Intensity Runway Lighting
HSI
Horizontal Situation Indicator
hPa
Hectopascals
IAF
Initial Approach Fix
IAP
Instrument Approach Procedure
IAS
Indicated Air Speed
ICAO
International Civil Aviation Organization
IEM
Interpretative and Explanatory Material ( for compliance with JAR-OPS 1 )
IF
Intermediate Fix
IFR
Instrument Flying Rules
ILS
Instrument Landing System ( see also GS and LOC )
ILS-DME
Instrument Landing System with collocated Distance Measuring Equipment
IMC
Instrument Meteorological Conditions
in.Hg
Inches of Mercury ( unit for pressure measurement )
INFO
Information service frequency
Glossary of terms and Abbreviations
Page 6
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Term
or
Abbreviation
Definition
IOE
Initial Operating Experience ( Line Training )
IRS
Inertial Reference System
JAA
European Joint Aviation Authority
JAR
European Joint Aviation Regulations
JAR-AWO
JAR - All Weather Operations requirements
JAR-OPS
JAR Operations requirements
JSAT
U.S. CAST Joint Safety Analysis Team
JSIT
U.S. CAST Joint Safety Implementation Team
JSSI
European Joint Safety Strategies and Initiatives
kt
LAAS
LAHSHO
Lateral Navigation
LDA
LLWAS
LOC
LOC BCK CRS
LOFT
m
Knots
GPS Local Area [accuracy] Augmentation System
Land and Hold Short operation
FMS managed lateral navigation ( i.e., NAV mode )
LOC-type Directional Aid
Low Level Windshear Alert System
Localizer
Localizer back course
Line Oriented Flight [simulator ] Training
Meters
Glossary of terms and Abbreviations
Page 7
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Term
or
Abbreviation
MAP
MCDU
MDA(H)
Definition
Missed Approach Point
Multi-purpose Control and Display Unit ( see also CDU )
Minimum Descent Altitude ( Height )
MEA
Minimum Enroute Altitude
MEL
Minimum Equipment List ( operator' customized version of MMEL )
METAR
Meteorological Airport [observation] Report
MMEL
Master Minimum Equipment List ( approved by operational authority )
Mode
Type of guidance used to guide the aircraft towards a target or set of targets,
or along a vertical flight path and/or lateral flight path
"Selected modes" refers to the modes armed or engaged by the pilot on the FCU
"Managed modes" refers to FMS vertical navigation and lateral navigation
MSA
Minimum Safe Altitude or Minimum Sector Altitude
MSAW
Minimum Safe Altitude Warning ( provided by ATC )
MSL
Mean Sea Level ( e.g., 1000 ft - altitude above MSL, indicated by the barometric
altimeter when set to QNH )
NATS
U.K. National Air Traffic Services
Navaid
Navigation Aid ( e.g., NDB, VOR, VOR-DME, LOC, ILS, ... )
ND
NDB
Navigation Display
Non Directional Beacon
Glossary of terms and Abbreviations
Page 8
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Term
or
Abbreviation
Next Target
Definition
Any required element or combination of one or more of the following elements:
- A position,
- An altitude,
- An aircraft configuration,
- A speed,
- A vertical speed, and/or
- A power setting.
NEXT WPT
nm
NOTAM
OAT
OCA(H)
The waypoint located after the TO WPT
Nautical miles
NOtice To AirMen
Outside Air Temperature
Obstacle Clearance Altitude ( Height )
OM
Outer Marker
PA
Passenger Address system
PAPI
PF
Precision Approach Path Indicator
Pilot Flying
PFD
Primary Flight Display
PIC
Pilot In Command
PIREPS
Pilot REPorts
Glossary of terms and Abbreviations
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Term
or
Abbreviation
PNF
Definition
Pilot Not Flying
The PNF is sometimes referred to as the Pilot Monitoring to enhance his/her role
in terms or monitoring, cross-check and backup
QAR
Quick Access Recorder
QFE
Actual atmospheric pressure at airport elevation
Altimeter setting required to read a height above airport elevation
QNH
Actual atmospheric pressure at sea level, based on actual atmospheric pressure at
station
Altimeter setting required to read an altitude above mean sea level ( MSL )
QRH
Quick Reference Handbook
R/I
Radio / Inertial navigation
RA
Depending on context :
- Radio Altimeter, or
- Resolution Advisory ( see also TCAS )
RA DH
Raw Data
REIL
Reversion
Radio Altimeter Decision Height
Raw navigation data : bearing and/or distance from aircraft to the tuned navaid
Runway End Identification Lights
A mode reversion is a manual or automatic changeover from one AP mode to another
mode ( usually, a lower level of automation ) resulting from:
- a pilot action ( e.g., the selection of a lower level of automation or the
disengagement of a mode for manual reversion to the AP basic mode );
- a system built-in condition ( e.g., a guidance limit or an active flight envelope
protection ); or,
- a failure or temporary loss of the engaged mode.
Glossary of terms and Abbreviations
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Term
or
Abbreviation
RMI
RNAV
Definition
Radio Magnetic Indicator
aRea NAVigation ( i.e., lateral navigation based on defined waypoints )
RNP
Required Navigation [accuracy] Performance
RVR
Runway Visual Range
RVSM
Reduced Vertical Separation Minima
SAT
Static Air Temperature
SDF
Simplified Directional Facility
SID
Standard Instruments Departure
SOPs
Standard Operating Procedures
Stabilization Height
The height above airfield elevation or the height above touchdown ( HAT ) at which
the aircraft should be stabilized for the approach to be continued
The stabilization height should be:
- 1000 ft in IMC; and,
- 500 ft in VMC
STAR
STD
TA
Target
TAS
Standard Terminal ARrival
Standard altimeter setting ( i.e., 1013.2 hPa or 29.92 in.hg )
Traffic Advisory ( see also TCAS )
A guidance target ( e.g., a speed, heading, altitude, vertical speed, flight path angle,
track, course, etc ) selected by the pilot on the appropriate panel (FCU, FMS CDU or
keyboard)
True Air Speed
Glossary of terms and Abbreviations
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Term
or
Abbreviation
TAWS
Definition
Terrain Awareness and Warning System
TAWS is the term used by the European JAA and the U.S. FAA to describe
equipment meeting ICAO standards and recommendations for ground-proximity
warning system (GPWS) equipment that provides predictive terrain-hazard warnings
Enhanced-GPWS ( EGPWS ) and ground collision avoidance system ( ACAS ) are
other terms used to describe TAWS equipment
TCAS
Traffic Collision Avoidance System ( see also ACAS )
TDWR
Terminal Doppler Weather Radar
Weather radar capable of detecting areas of wind shear activity
TDZ
Touch Down Zone
TDZE
Touch Down Zone Elevation
TERPS
U.S. Standard for Terminal Instrument Approach Procedures ( FAR - Part 97 )
TO WPT
Waypoint of the F-PLN flight plan considered by the FMS for immediate lateral
navigation guidance ( in case of incorrect flight plan sequencing, the TO WPT may
happen to be behind the aircraft )
TOD
Transition
Top Of Descent
A mode transition is a manual or automatic changeover from one AP mode to another
mode, resulting from:
- a pilot action ( e.g., the selection of a new mode on the FCU, as appropriate for
the task or following an ATC instruction ); or,
- an automatic mode sequencing resulting from a prior mode selection involving
several mode changes in sequence ( e.g., altitude capture changeover to altitude
hold or selected heading changeover to localizer capture then to localizer tracking )
V APP
Final Approach Speed
V MCL
Minimum control speed in landing configuration with the critical engine inoperative
Glossary of terms and Abbreviations
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Term
or
Abbreviation
Definition
V REF
Reference approach speed ( also referred to as threshold reference speed or target
threshold speed )
V stall
Stalling speed ( in a specified configuration )
V/S
Vertical speed or AP Vertical Speed mode
VASI
Visual Approach Indicator
VDP
Visual Descent / Decision Point
Vertical Navigation
FMS-managed vertical navigation
VFR
Visual Flying Rules
VHF
Very High Frequency
VMC
Visual Meteorological Conditions
VOR
VHF Omni Range
VOR-DME
Collocated VOR and DME navaids
WAAS
GPS Wide Area [accuracy] Augmentation System
WMO
World Meteorological Organization
Glossary of terms and Abbreviations
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Chapter 1
Operating Philosophy - SOPs
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Approach-and-Landing Briefing Note
1.1 – Operating Philosophy - SOPs
Introduction
Statistical Data
Strict adherence to suitable standard operating
procedures (SOPs) and normal checklists is an
effective method to prevent approach-and-landing
accidents, including those involving CFIT.
Omission
of
action
inappropriate action
Without
strict
adherence
to
SOPs,
the
implementation of good crew resources management
(CRM) practices is not possible.
This Briefing Note provides an overview of the
following aspects:
•
Establishment and use of (SOPs);
•
Training aspects; and,
•
Factors and conditions that may affect the
compliance with published rules and procedures.
% of
Events
Factor
or
72 %
Non-adherence to criteria for
stabilized approach
66 %
Inadequate crew coordination,
cross-check and back-up
63 %
Insufficient horizontal or vertical
situational awareness
52 %
Inadequate
or
understanding
of
conditions
48 %
insufficient
prevailing
Slow or delayed action
Deliberate non-adherence
procedures
45 %
to
40 %
Incorrect or incomplete pilot /
controller communications
33 %
Interaction with automation
20 %
Absence
required
17 %
of
go-around when
Table 1
Causal Factors related to SOPs
in Approach-and-Landing Accidents
Standard Operating Procedures
Page 1
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Airbus Industrie’ SOPs
Line pilots and cabin crewmembers should be
involved, along with the flight standards team, in the
development and revision process of company SOPs
to:
Standard Operating Procedures (SOPs) published by
Airbus Industrie are designed to achieve the following
objectives:
•
Reflect the Airbus Industrie’ cockpit design
philosophy and operating philosophy;
•
Promote optimum use of aircraft-type design
features; and,
•
Apply to a broad range of airline operations and
environments.
•
Promote critical and constructive feedback; and,
•
Ensure that rules and procedures, as well as
reasons for their adoption are fully understood by
end users.
Scope of SOPs
The initial SOPs for a new aircraft model are based
on the above objectives and on the experience
gained during the development and certification flighttest campaign and during the route-proving program.
SOPs should identify and describe the standard
tasks and duties of flight -crew for each flight phase.
SOPs should be accomplished by recall but critical
tasks (e.g., selections of systems and changes of
aircraft configuration) should be cross-checked by
use of normal checklists, according to the phase of
flight.
After they are introduced into service, the initial
SOPs are periodically reviewed and enhanced based
on the feedback received from various users (i.e., in
training and in line operations).
SOPs should be supplemented by information on
specific operating techniques (e.g., adverse weather
operation) or by operational recommendations for
specific types of operations (e.g., operation on wet or
contaminated runway, operation in ETOPS area
and/or in RVSM airspace).
Operator’ Customized SOPs
Airbus Industrie’ SOPs can be adopted without
change by an operator or used as the basis for the
development of customized company’ SOPs.
SOPs should assume that all aircraft systems
operate normally and that all automatic functions are
used normally.
Customized company SOPs usually are established
to assure standardization across the different aircraft
fleets being operated by the airline.
Note :
A system may be partially or totally inoperative
without affecting the SOPs.
Deviations from the Airbus Industrie’ SOPs may be
coordinated with Airbus Industrie, such deviations
usually require approval by the airline’s operational
authority.
SOPs should emphasize the following aspects
frequently
involved
in
approach-and-landing
accidents:
SOPs should be simple, clear, concise and directive;
the level of expanded information should be tailored
to reflect the airline’s operating philosophy and
training philosophy.
Operator’s SOPs should be reviewed and
reassessed periodically based on revisions of the
Airbus Industrie’s SOPs and on internal company
feedback, to identify any need for change.
•
Task sharing;
•
Optimum use of automation;
•
Operations Golden Rules;
•
Standards calls;
Standard Operating Procedures
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•
Use of normal checklists;
•
Approach and go-around briefings;
The European JAA defines the scope and contents
of SOPs in JAR-OPS 1.1045 and associated
Appendix 1.
•
Altimeter setting and cross-check procedures;
•
Descent profile management;
•
Energy management;
•
Terrain awareness;
•
Approach hazards awareness;
•
Use of radio altimeter;
•
Elements of a stabilized approach and approach
gates;
•
Approach procedures and techniques for various
types of approaches;
•
Landing and braking techniques for various types
of runway and wind conditions; and,
•
The scope of SOPs defined in the FAA AC 120-71 is
allocated by the JAA to the Part A and Part B of the
Operations Manual, as follows:
•
Part A : General operational policies (i.e., nontype-related matters); and,
•
Part B : Aeroplane operating matters (i.e., typerelated matters).
General Principles
SOPs should contain safeguards in order to
minimize the potential for inadvertent deviation from
procedures, particularly when operating under
abnormal or emergency conditions or following
interruptions or distractions.
Safeguards include:
•
− events or actions initiating groups of actions
(called action-blocks);
Readiness and commitment to go-around
(e.g., GPWS warning, unstabilized approach,
bounce recovery).
•
•
The U.S. FAA defines the scope and contents of
SOPs in Advisory Circular (AC) 120-71.
•
•
Airplane operating matters (i.e., type-related)
(i.e.,
Standard calls:
− standard phraseology and terms used for
effective intra-crew communication.
The SOPs defined in AC 120-71 includes items
related to:
policies
Action patterns:
− flightdeck panel scanning sequences or
patterns supporting the flow and sequence of
action blocks; and,
Regulatory Definition
General operations
related); and,
Action blocks:
− groups of actions being accomplished in
sequence as a group;
In addition, SOPs should address the following
aspects:
•
Triggers:
non-type
Standardization
SOPs (including standard calls) constitute the
reference for crew standardization and provide the
working environment required for enhanced and
efficient crew communication and coordination.
Standard Operating Procedures
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Task Sharing
Silent Cockpit
The following rules apply to any flight phase but are
particularly important in the high-workload phases
associated with approach and landing.
The Sterile Cockpit rule and the Silent Cockpit
concept often are misunderstood as referring to the
same operating policy.
The pilot flying (PF) is responsible for controlling the
vertical flight path and horizontal flight path and for
energy management, by either:
When adhering to a Silent Cockpit policy, standard
calls are minimized; FCU selections, FMA changes
and target confirmations on PFD and ND are not
announced loudly but included in the instruments
scan.
•
Supervising the autopilot vertical guidance and
lateral guidance and the autothrust operation
(i.e., awareness of modes being armed or
engaged, and of mode changes through mode
transitions and reversions);
Airbus Industrie acknowledges that variations may
exist in airline operating policies but encourages
operators to adopt and adhere to a Standard Calls
policy, as defined in Briefing Note 1.4 – Standard
Calls.
or,
•
Hand flying the aircraft, with or without flight
director (FD) guidance, and with an adapted
navigation display (e.g., ROSE or ARC mode).
Use of Automation
With higher levels of automation, flight crews are
offered an increasing number of options and
strategies to choose for the task to be
accomplished.
The pilot not flying (PNF) is responsible for
monitoring tasks and for performing the actions
requested by the PF; this includes:
•
Performing the standard PNF tasks:
The company SOPs should accurately define the
options and strategies selected by the airline for the
various flight phases and for the various types of
approaches.
− SOP actions; and,
− Flight director and FMS mode selections and
target entries, when in manual flight;
•
Monitoring the current status of the aircraft; and,
•
Monitoring the PF to provide effective backup as
required (this includes both flight and ground
operation).
Briefing Note 1.2 - Optimum Use of Automation
provides expanded information on the use of AP/FD,
A/THR and FMS.
Scope and Use of Normal Checklists
Briefing Note 1.5 - Normal Checklists provides a
detailed overview on the scope and use of normal
checklists.
Sterile Cockpit Rule
Adhering to the Sterile Cockpit rule (defined in
Briefing Note 2.4 – Intra-Cockpit Communications,
Managing Interruptions and Distractions ) may be
mandated by operational authorities (e.g., U.S. FAR
– Part 121.542 ) or adopted per company policy.
Training Aspects
Disciplined use of SOPs and normal checklists
should begin during the transition training course,
because habits and routines acquired during
transition training have a lasting effect.
Airbus Industrie encourages adherence to the Sterile
Cockpit rule, regardless of applicable national
requirements.
Standard Operating Procedures
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Transition training and recurrent training provide a
unique opportunity to discuss the reasons for the
rules and procedures and to discuss the
consequences of failing to comply with them.
•
Incorrect CRM techniques (e.g., absence of
cross-checking, crew coordination or effective
backup);
•
Conversely, allowing a relaxed adherence to SOPs
and/or a relaxed use of normal checklists during
initial or recurrent simulator training may encourage
corresponding deviations during line operations.
Company policies (e.g., regarding schedules,
costs, go-around and diversion);
•
Other policies (e.g., crew duty time);
•
Personal desires or constraints (e.g., schedule,
mission completion);
Factors Involved in Deviations from SOPs
•
Complacency; and,
•
Overconfidence (e.g., high time on aircraft type).
To ensure effective compliance with published SOPs,
it is important to understand why pilots intentionally
or inadvertently deviate from rules or standards.
These factors may be used to assess company
and/or personal exposure, and to develop
corresponding prevention strategies and lines -ofdefense.
In most cases of deviation from SOPs, the procedure
that was followed in place of the published procedure
seemed to be appropriate for the prevailing situation,
considering the information available at the time.
Summary of Key Points
The following factors and conditions are cited often in
discussing deviations from SOPs:
•
SOPs should include and emphasize aspects that
are involved frequently in approach-and-landing
accidents.
Inadequate knowledge of or failure to understand
the
rule,
procedure
or
action
(e.g., due to quality of wording or phrasing, rule
or procedure or action being perceived as
inappropriate);
Company policies, technical training and CRM
training programs, line checks and line audits
should:
•
Insufficient emphasis on strict adherence to
SOPs during transition and recurrent training;
•
Insufficient vigilance (fatigue);
•
Distractions (e.g., due to intra-cockpit activity);
•
Interruptions (e.g., due to ATC communication);
Associated Briefing Notes
•
Task saturation (i.e., absence of multi-tasking
ability or task overload);
•
Incorrect management of priorities (e.g., lack of
decision-making
model
for
time-critical
situations);
The following Briefing Notes should be reviewed
along with the above general information in order to
revisit all the aspects associated with standard
operating procedures:
•
Reduced attention ( tunnel vision ) in abnormal or
high-workload conditions;
•
Promote strict adherence to SOPs; and,
•
Identify and address the reasons for intentional
or inadvertent deviations from SOPs.
•
1.2 - Optimum Use of Automation,
•
1.3 - Operations Golden Rules,
•
1.4 - Standard Calls,
•
1.5 - Use of Normal Checklists,
Standard Operating Procedures
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•
1.6 - Approach and Go-around Briefings,
•
2.1 - HF Issues in Approach and Landing
Accidents,
•
FAA AC 120-71 - Standard Operating
Procedures for Flightdeck Crew Members (Draft).
•
FAA AC 120-48 – Communications and
Coordination between Flight Crewmembers and
Flight Attendants.
•
FAA AC 120-51 – Crew Resource Management
Training.
•
FAA AC 120-54 – Advance Qualification Training.
•
FAA AC 120-71 – Standard Operating
Procedures for Flight Deck Crewmembers.
•
FAA AC 121-32 –
Management Training.
•
JAR-OPS 1.1040 and associated Interpretative
and Explanatory Material (IEM) – General Rules
for Operations Manuals.
•
JAR-OPS 1.1045 and associated Appendix 1,
Acceptable Means of Compliance (AMC) and
Interpretative and Explanatory Material (IEM) –
Operations Manual – structure and contents.
2.2 - CRM Issues in Approach and Landing
Accidents.
Regulatory References
•
•
ICAO – Annex 6 – Operation of Aircraft, Part I –
International Commercial Air transport –
Aeroplanes, Appendix 2, 5.9.
•
ICAO – Procedures for Air Navigation Services –
Aircraft Operations (PANS-OPS, Doc 8168),
Volume I – Flight procedures (Post Amendment
No 11, applicable Nov.1/2001).
•
ICAO – Manual of All-Weather Operations
(Doc 9365).
•
ICAO – Preparation of an Operations Manual
(Doc 9376).
•
FAR 91.3 – Responsibility and authority of the
pilot-in-command (emergency authority).
•
FAR 121.133 – Preparation of Manuals,
•
FAR 121.135 – Contents of Manuals,
Standard Operating Procedures
Page 6
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Approach-and-Landing Briefing Note
1.2 - Optimum Use of Automation
Higher levels of automation provide flight crews with
an increasing number of options and strategies to
choose for the task to be accomplished.
Introduction
Optimum use of automation refers to the integrated
and coordinated use of the following systems:
•
Autopilot / flight director (AP / FD);
•
Autothrottle/autothrust (A/THR); and,
•
Flight management system (FMS).
The applicable FCOM provides specific information
for each aircraft type.
Statistical Data
Errors in using and managing the automatic flight
system and the lack of awareness of the operating
modes are causal factors in more than 20 % of
approach-and-landing accidents.
Three generations of flight guidance systems are
currently in airline service, providing different levels
of integration and automation:
•
•
•
A300B2/B4 and A300 FFCC families:
−
Partial integration (pairing) of the AP/FD and
A/THR modes;
−
Selected vertical and lateral modes; and,
−
Lateral navigation only (i.e., inertial
navigation system [INS] or FMS/GPS).
AP - A/THR Integration
Integrated
AP-A/THR
systems
feature
an
association (pairing) of AP pitch modes (elevator
control) and A/THR modes (throttle/thrust levers
control).
A310 and A300-600 families:
An integrated AP-A/THR operates in the same way
as a human pilot:
−
Full integration of AP/FD and A/THR
modes;
•
−
Selected vertical and lateral modes; and,
Elevator is used to control pitch attitude,
airspeed,
vertical
speed,
altitude,
flight-path-angle, vertical navigation profile or to
track a glideslope beam;
−
Vertical and lateral navigation (FMS),
•
Throttle/thrust levers are used to maintain a
given thrust or a given airspeed.
A320 / A330 / A340 families:
−
Full integration of AP/FD - A/THR – FMS
modes (FMGS);
−
Selected vertical and lateral modes; and,
−
Managed vertical and lateral navigation in all
flight phases.
Throughout the flight, the pilot’s objective is to fly:
•
Performance segments at constant thrust or at
idle (e.g., takeoff, climb or descent); or,
•
Trajectory segments at
(e.g., cruise or approach).
Optimum Use of Automation
Page 1
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Depending on the task to be accomplished,
maintaining the airspeed is assigned either to the
AP (elevators) or to the A/THR (throttles/thrust
levers), as shown in Table 1.
A/THR
Throttles /
The FCU constitutes the main interface between the
pilot and the autoflight system for short-term
guidance (i.e., for immediate guidance).
The FMS multi-purpose control and display unit
(MCDU) constitutes the main interface between the
pilot and the autoflight system for long-term
guidance (i.e., for the current and subsequent flight
phases).
AP
On aircraft equipped with an FMS featuring both
lateral and vertical navigation, two types of guidance
(modes and associated targets) are available:
Elevators
Thrust levers
Performance
•
Thrust or idle
Speed
− the aircraft is guided to acquire and maintain
the targets set by the crew on the FCU, using
the modes engaged on the FCU.
Segment
V/S
Trajectory
Speed
Segment
Selected guidance:
•
Vertical profile
FMS (managed) guidance:
− the aircraft is guided along the FMS lateral
and vertical flight plan, speed profile and
altitude targets, as managed by the FMS
(accounting
for
altitude
and
speed
constraints, as applicable).
Altitude
Glide slope
Table 1
Understanding Automated Systems
AP – A/THR Modes Integration
Understanding any automated system, but
particularly the AFS and FMS, ideally would require
answering the following fundamental questions:
Design Objective
The design objective of the automatic flight system
(AFS) is to provide assistance to the crew
throughout the flight (within the normal flight
envelope), by:
•
How is the system designed ?
•
Why is the system designed this way ?
•
•
How does the system interface and communicate
with the pilot ?
•
How to operate the system in normal and
abnormal situations ?
•
Relieving the PF from routine handling tasks
and thus allowing time and resources to
enhance his/her situational awareness or for
problem solving tasks; and,
Providing the PF with adequate attitude and
flight path guidance through the FD, for hand
flying.
The following aspects should be fully understood for
an optimum use of automation:
The AFS provides guidance to capture and maintain
the selected targets and the defined flight path, in
accordance with the modes engaged and the
targets set by the flight crew on the FCU or on the
FMS CDU.
•
Integration of AP/FD
(i.e., pairing of modes);
•
Mode transition and reversion sequences;
Optimum Use of Automation
Page 2
and
A/THR
modes
•
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Pilot-system interfaces for:
Effective monitoring of these controls and displays
promotes and increases flight crew awareness of:
− Pilot-to-system communication (i.e., for
modes engagement and target selections);
and,
− System-to-pilot feedback (i.e., for modes and
targets cross-check).
•
The status of the system (i.e., modes being
engaged or armed); and,
•
The available guidance (i.e., for flight path and
speed control).
Effective monitoring of controls and displays also
enables the pilot to predict and anticipate the entire
sequence of flight modes annunciations (FMA)
throughout flight phases (i.e., throughout mode
transitions or mode reversions).
In the context of this Briefing Note, the interface and
communication between the flight crew and the
system need to be emphasised.
Flight Crew / System Interface
Operating Philosophy and Rules
When performing an action on the FCU or FMS
CDU to give a command to the AFS, the pilot has
an expectation of the aircraft reaction and,
therefore, must have in mind the following
questions:
•
What do I want the aircraft to fly now ?
•
What do I want to fly next ?
Optimum use of automation requires strict
adherence to the design philosophy and operating
philosophy, and to the following rules of operation.
Use the correct level of automation for
the task
On highly automated and integrated aircraft, several
levels of automation are available to perform a given
task:
This implies answering also the following questions :
•
Which mode did I engage and which target did
I set for the aircraft to fly now ?
•
Is the aircraft following the intended vertical and
lateral flight path and targets ?
•
FMS modes and guidance; or,
•
Selected modes and guidance.
The correct level of automation depends on:
•
Which mode did I arm and which target did I pre
set for the aircraft to fly next ?
•
− short-term (tactical) task; or,
The key role of the following controls and displays
therefore must be understood:
•
•
− long-term (strategic) task;
•
FCU mode selection-keys, target-setting knobs
and display windows;
Flight modes annunciator (FMA) annunciations
on PFD; and,
•
PFD and ND data.
The flight phase:
− enroute;
− terminal area; or,
FMS MCDU keyboard, line-select keys, display
pages and messages;
•
The task to be performed:
− approach; and,
•
The time available:
− normal selection or entry; or,
− last-minute change.
Optimum Use of Automation
Page 3
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The correct level of automation often is the one the
pilot feels comfortable with for the task or for the
prevailing conditions, depending on his/her
knowledge and experience of the aircraft and
systems.
Any action on the FCU or on the FMS keyboard and
line-select keys should be confirmed by crosschecking the corresponding annunciation or data on
the PFD and/or ND (and on the FMS CDU).
At all times, the PF and PNF should be aware of the
status of the guidance modes being armed or
engaged and of any mode change-over throughout
mode transitions and reversions.
Reversion to hand flying and manual thrust control
actually may be the correct level of automation,
depending on the prevailing conditions.
FMS or selected guidance can be used in
succession or in combination (e.g., FMS lateral
guidance together with selected vertical guidance)
as best suited for the flight phase and prevailing
constraints.
Enhanced reference to the above controls and
displays promotes and increases the flight crew
awareness of :
•
The status of the system (i.e., modes being
armed or engaged),
The PF always retain the authority and capability to
select the most appropriate level of automation and
guidance for the task, this includes:
•
The available guidance (i.e., for flight path and
speed control).
•
Adopting a more direct level of automation by
reverting from FMS-managed guidance to
selected guidance (i.e., to selected modes and
targets);
This enables the flight crew to predict and anticipate
the entire sequence of flight mode annunciations
throughout successive flight phases (i.e., throughout
mode transitions or reversions).
•
Selecting a more appropriate lateral or vertical
mode; or,
•
Reverting to hand flying (with or without FD
guidance, with or without A/THR) for direct
control of aircraft vertical trajectory, lateral
trajectory and thrust.
Monitor automation at all times
The use and operation of the AFS must be
monitored at all times by:
Know your Available Guidance at all times
The FCU and the FMS CDU are the prime
interfaces for the flight crew to communicate with
the aircraft systems (i.e., to arm or engage modes
and to set targets).
The PFD and ND are the prime interfaces for the
aircraft to communicate with the flight crew, to
confirm that the aircraft systems have correctly
accepted the mode selections and target entries:
•
•
•
Observing and announcing the result of any
target setting or change (on the FCU) on the
related PFD and/or ND scales; and,
•
Supervising the resulting AP/FD guidance and
A/THR operation on the PFD and ND (pitch
attitude and bank angle, speed and speed trend,
altitude, vertical speed, heading or track, …).
If doubt exists regarding the aircraft flight path or
speed control, no attempt at reprogramming the
automated systems should be made.
guidance modes, speed and altitude targets;
and,
ND :
−
Checking and announcing the status of AP/FD
modes and A/THR mode on the FMA
(i.e., arming or engagement);
Be ready to take over, if required
PFD (FMA, speed scale and altitude scale):
−
•
Selected guidance or hand flying together with the
use of navaids raw data should be used until time
and conditions permit reprogramming the AP/FD or
FMS.
lateral guidance ( heading or track or
FMS flight plan).
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If the aircraft does not follow the intended flight path,
check the AP and A/THR engagement status.
•
Insufficient understanding of mode transitions
and mode reversions (i.e., mode confusion);
If engaged, disconnect the AP and/or A/THR using
the associated instinctive disconnect push button(s),
to revert to hand flying (with FD guidance or with
reference to raw data) and/or to manual thrust
control.
•
Inadequate task sharing and/or CRM practices
preventing the PF from monitoring the flight path
and airspeed;
(e.g., both pilots being engaged in the
management of automation or in solving an
unanticipated situation or abnormal condition);
In hand flying, the FD commands should be
followed; otherwise the FD bars should be cleared
from display.
AP and A/THR must not be overridden manually.
If AP or A/THR operation needs to be overridden
(i.e., following a runaway or hardover), immediately
disconnect the affected system by pressing the
associated instinctive disconnect push button.
•
Failure to verify the mode armed or engaged, by
reference to the FMA ;
•
Selection of an incorrect target (altitude, speed,
heading) on the FCU and failure to confirm the
selected target on the PFD and/or ND (as
applicable);
•
Insertion of an erroneous waypoint;
•
Arming of the lateral navigation mode with an
incorrect active waypoint (i.e., an incorrect TO
waypoint);
•
Failure to arm the approach mode; and/or,
•
Failure to set the correct final approach course.
•
An unanticipated change; or,
•
An abnormal or emergency condition.
During line operations, AP and A/THR should be
engaged throughout the flight especially in marginal
weather conditions or when operating into an
unfamiliar airport.
Using AP and A/THR also enables flight crew to pay
more attention to ATC communications and to other
aircraft, particularly in congested terminal areas and
at high-density airports.
Selection of the FCU altitude to any altitude below
the final approach intercept altitude during
approach;
•
•
Correct use of automated systems reduces workload
and significantly improves the flight crew time and
resources for responding to:
The following factors and errors can cause flying an
incorrect flight path, which - if not recognized - can
lead to an approach-and-landing accident, including
one involving CFIT:
Inadvertent arming or engagement of an incorrect
mode;
Engaging the AP with the aircraft in an out-of-trim
condition (conventional aircraft only);
Recommendations for Optimum Use of
Automation
Factors and Errors in Using Automation
•
•
AP and A/THR should be used during a go-around
and missed-approach to reduce workload.
FMS lateral navigation should be used to reduce
workload and risk of CFIT during go-around if :
Preoccupation with FMS programming during a
critical flight phase, with consequent loss of
situational awareness;
•
Applicable missed-approach procedure
included in the FMS flight plan; and,
•
FMS navigation accuracy has been confirmed.
Optimum Use of Automation
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The safe and efficient use and management of AP,
A/THR and FMS are based on the following threestep technique:
•
Announce all changes in accordance with
Standard Calls defined in SOPs;
•
•
When changing the selected altitude on FCU,
cross-check the selected altitude indication on
PFD;
Anticipate:
− Understand system operation and results of
any action, be aware of modes being armed
or engaged (seek concurrence of other
crewmember, if deemed necessary);
•
During descent, ensure that selected altitude is
not to below the MEA or MSA (or be aware of the
applicable minimum-vectoring-altitude);
During final approach, set go-around altitude on
FCU (i.e., the MDA/H or DA/H should not be set);
Execute:
− Perform action on FCU or on FMS CDU; and,
•
•
Confirm:
− Crosscheck and announce arming or
engagement of modes and targets selections
(on FMA, PFD and/or ND scales or FMS
CDU).
An alternative arrival routing, another runway or
circling approach, can be prepared on the
secondary flight plan, as anticipated;
•
The following rules and recommendations should be
considered to support the implementation of this
technique:
•
Before engaging the AP, make sure that:
−
−
Prepare FMS for arrival before starting the
descent;
In case of a routing change (e.g., DIR TO), crosscheck the new TO waypoint before activating the
DIR TO (i.e., making sure that the intended
TO waypoint is not already behind the aircraft);
Modes engaged for FD guidance (check
FMA annunciations) are the correct modes
for the intended flight phase and task;
Caution is essential during descent in
mountainous areas; ensure that the new track
and assigned altitude are not below the sector
safe altitude;
Select the appropriate mode(s), as required;
and,
If under radar vectors, be aware of the sector
minimum vectoring-altitude;
Command bars do not shows large orders;
if large commands are given, maintain hand
flying to center the bars before engaging
AP;
If necessary, the selected heading mode can be
used with reference to navaids raw data, while
verifying the new route and/or requesting
confirmation from ATC;
•
Engaging the AP while large commands are
required to achieve the intended flight path
may result in the AP overshooting the
intended vertical target or lateral target;
Before arming the NAV mode, ensure that the
correct active waypoint (i.e., TO waypoint) is
displayed on the FMS CDU and ND (as
applicable);
•
Before any action on FCU, check that the knob or
push button is the correct one for the desired
function;
If the displayed TO waypoint on the ND is not
correct, the desired TO waypoint can be restored
by either:
•
After each action on FCU, verify the result of this
action on:
− clearing an undue intermediate waypoint; or,
−
FMA (i.e., for arming or engagement of
modes); and/or,
− performing a DIR TO [desired TO waypoint].
−
PFD/ND data (i.e., for selected targets); and,
Monitor the correct interception of the FMS lateral
flight plan;
by reference to the aircraft flight path and
airspeed response;
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•
In case of a late routing or runway change,
a reversion to AP selected modes and raw data is
recommended;
Reprogramming the FMS during a critical flight
phase (e.g., in terminal area, on final approach or
go-around) is not recommended, except to
activate the secondary flight plan, if prepared, or
for selecting a new approach;
At any time, if the aircraft does not follow the
desired flight path and/or airspeed, do not
hesitate to revert to a more direct level of
automation:
− revert from FMS-managed modes to selected
modes;
or,
Priority tasks are, in that order :
− disconnect AP and follow FD guidance (if
correct);
−
horizontal and vertical flight path control;
or,
−
altitude and traffic awareness; and,
−
ATC communications;
− disengage FD, select FPV (as available) and
hand fly the aircraft, using raw data or visually
(if in VMC);
•
No attempt should be made to analyze or rectify
an anomaly by reprogramming the AFS or FMS,
until the desired flight path and/or airspeed are
restored;
•
In case of AP uncommanded disconnection,
the second AP should be engaged immediately to
reduce PF’s workload (i.e., only dual or multiple
failures may affect both APs simultaneously);
•
If cleared to exit a holding pattern on a radar
vector, the holding exit prompt should be pressed
(or the holding pattern cleared) to allow the
correct sequencing of the FMS flight plan;
•
Under radar vectors, when intercepting the final
approach course in a selected heading or track
mode (i.e., not in NAV mode), flight crew should
ensure that FMS flight plan sequences normally
by checking that the TO waypoint is correct (on
ND and FMS CDU);
and/or,
− disengage the A/THR and control the thrust
manually.
Summary of key points
For optimum use of automation, the following
should be promoted:
•
Understanding the integration of AP/FD and
A/THR modes (i.e., pairing of modes);
•
Understanding all mode transition and reversion
sequences;
•
Understanding pilot-system interfaces for:
− Pilot-to-system communication (i.e., for
modes engagement and target selections);
− System-to-pilot feedback (i.e., for modes and
targets cross-check);
Ensuring that FMS flight plan sequences correctly
with a correct TO waypoint is essential to reengage the NAV mode, in case of a go-around;
If FMS flight plan does not sequence correctly,
correct sequencing can be restore by either:
− performing a DIR TO [ a waypoint ahead in
the approach ] or a DIR TO INTCPT (as
available); or,
− clearing an undue intermediate waypoint (be
cautious
not
to
clear
the
desired
TO waypoint).
If a correct TO waypoint cannot be restored, the
NAV mode should not be used for the rest of the
approach or for go-around;
•
Awareness of available guidance (AP/FD and
A/THR status, modes armed or engaged, active
targets);
•
Alertness to adapt the level of automation to the
task and/or circumstances, or to revert to hand
flying / manual thrust control, if required;
•
Adherence to design philosophy and operating
philosophy, SOPs and Operations Golden
Rules.
Optimum Use of Automation
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Associated Briefing Notes
The following Briefing Notes should be reviewed
along with the above information to complement this
overview on the use of automation:
•
1.1 - Operating Philosophy - SOPs,
•
1.3 - Operations Golden Rules,
•
1.4 - Standard Calls.
Regulatory references
•
ICAO – Annex 6 Operation of Aircraft, part I –
International
Commercial
transport
–
Aeroplanes, Appendix 2, 5.14.
•
ICAO – Human Factors Training Manual
(Doc 9683).
•
ICAO – Human Factors Digest No 5 –
Operational Implications of Automation in
Advanced Technology Flight Decks (Circular
234).
•
FAR 121-579 - Minimum altitudes for the use of
the autopilot.
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Approach-and-Landing Briefing Note
1.3 - Operations Golden Rules
Introduction
Statistical Data
Golden Rules have always guided human activities.
The following factors frequently are identified as
causal factor in approach-and-landing accidents:
In early aviation days, the Golden Rules defined the
basic principles of airmanship.
% of
Events
Factor
With the development of technology in modern
aircraft and with research on man-machine-interface
and crew-coordination, Golden Rules have been
broadened to encompass the principles of
interaction with automation and crew resources
management (CRM).
Inadequate decision making
74 %
Omission
of
action
inappropriate action
or
72 %
The operations Golden Rules defined by Airbus
Industrie assist trainees in maintaining their basic
airmanship even as they progress to integrated and
automated aircraft models.
Inadequate CRM practice
(crew coordination, crosscheck and backup)
63 %
Insufficient
horizontal
or
vertical situational awareness
52 %
Although developed for trainees, the Golden Rules
are equally useful for experienced line pilots.
Inadequate or insufficient
understanding of prevailing
conditions
48 %
Golden Rules address aspects that are considered
frequent causal factors in approach and landing
accidents:
Slow or delayed crew action
45 %
Flight handling difficulties
45 %
Incorrect
or
pilot/controller
communication
33 %
These rules apply with little modification to all Airbus
models.
•
Inadequate situational / positional awareness;
•
Incorrect interaction with automation;
•
Overreliance on automation; and,
•
Ineffective
backup.
crew
cross-check
incomplete
Interaction with automation
and
20 %
mutual
Table 1
Most Frequent Causal Factors
in Approach-and-Landing Accidents
Operations Golden Rules
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•
General Golden Rules
Navigate :
The following eight Golden Rules are applicable in
normal conditions and, more importantly, in any
unanticipated or abnormal / emergency condition.
Select the desired modes for vertical navigation
and lateral navigation (i.e., selected modes or
FMS-managed navigation), being aware of
surrounding terrain and minimum safe altitude.
Automated aircraft can be flown like any
other aircraft.
This rule can be summarized by the following
three “ know where …” situational-awareness
items:
To promote this rule, each trainee should be given
the opportunity to fly the aircraft just using the stick,
rudder and throttles.
− Know where you are;
− Know where you should be; and,
− Know where the terrain and obstacles are.
The use of flight director (FD), autopilot (AP),
autothrottle/autothrust
(A/THR)
and
flight
management system (FMS) should be introduced
progressively, as defined by the applicable training
syllabus.
•
Effective
crew
communication
involves
communications between flight crewmembers
and communications between flight crew and
cabin crew.
Practice of hand flying will illustrate that the pilot
flying (PF) always retains the authority and capability
to adopt:
•
A more direct level of automation; or revert to,
•
Hand flying, directly controlling the aircraft
trajectory and energy.
In an abnormal or emergency condition, after a
stable flight path has been regained and the
abnormal or emergency condition has been
identified, the PF should inform the ATC of the
prevailing condition and of his/her intentions.
Fly, Navigate, Communicate and Manage –
in that order
To attract the controller’s attention, use the
following standard phraseology, as applicable:
− Pan Pan – Pan Pan – Pan Pan; or
Task sharing should be adapted to the prevailing
situation (i.e., task sharing for hand flying or with AP
engaged, task sharing for normal operation or for
abnormal / emergency conditions, as defined in
FCOM) and tasks should be accomplished in
accordance with the following priorities:
•
Communicate :
− Mayday – Mayday – Mayday.
•
Manage :
Managing the continuation of the flight is the
next priority, this includes:
Fly :
•
PF must concentrate on flying the aircraft
(i.e., by controlling and/or monitoring the pitch
attitude, bank angle, airspeed, thrust, sideslip,
heading, ...) to capture and maintain the desired
targets, vertical flight path and lateral flight path.
Managing aircraft systems (e.g., fuel
management, ETOPS management, etc);
and,
•
Performing applicable emergency and/or
abnormal procedure(s).
PNF must backup the PF by monitoring flight
parameters and by calling any excessive
deviation.
Specific Golden Rules to assist flight crew in
their decision-making and management process
are provided in the second part of this Briefing
Note.
Operations Golden Rules
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The design of glass-cockpit aircraft fully supports
the above four-step strategy, as summarized in
Table 1.
Golden Rule
Display Unit
Fly
PFD
Navigate
ND
Communicate
DCDU
Manage
ECAM
Critical or irreversible actions, such as selecting an
engine fuel lever / master switch or a fuel isolation
valve to OFF, should be accomplished by the PNF
but require prior confirmation by the PF
(i.e., confirmation loop).
Know your FMA guidance at all times
The FCU and FMS CDU and keyboard are the
prime interfaces for the crew to communicate with
aircraft systems (i.e., to arm modes or engage
modes and to set targets).
The PFD (particularly the FMA and target symbols
on speed scale and altitude scale) and ND are the
prime interfaces for the aircraft to communicate with
the crew, to confirm that the aircraft systems have
correctly accepted the flight crew’s mode selections
and target entries.
Table 1
Glass-cockpit Design Supports Golden Rules
Any action on FCU or on FMS keyboard and lineselect keys should be confirmed by cross-checking
the corresponding annunciation or data on PFD
and/or ND.
Practice task sharing and back-up each
other
Task sharing, effective cross-check and backup
should be practiced in all phases of ground and
flight operation, in normal operation or in abnormal /
emergency conditions.
At all times, the PF and PNF should be aware of:
•
Modes armed or engaged;
•
Guidance targets set; and,
Emergency, abnormal and normal procedures
(i.e., normal checklists) should be performed as
directed by ECAM and/or QRH, e.g. :
•
Mode transitions or reversions.
•
Cross check the accuracy of the FMS with
raw data
•
In case of an emergency condition:
−
Emergency procedure;
−
Normal checklist ( as applicable ); and,
−
Abnormal procedure(s).
In case of an abnormal condition:
When within navaids coverage area, FMS
navigation accuracy should be cross-checked
against navaids raw-data (unless aircraft is GPSequipped and GPS PRIMARY is available).
−
Abnormal procedure down to STATUS;
FMS navigation accuracy can be checked by:
−
Normal checklist ( as applicable ); and,
•
−
Resuming abnormal procedure.
Entering
a
tuned
VOR-DME
in
the
bearing/distance ( BRG / DIST TO ) field of the
appropriate FMS page;
•
Comparing the resulting FMS DIST TO reading
with the DME distance read on the RMI (or on
ND, as applicable);
These actions should be accomplished in
accordance with the published task sharing, crew
coordination principles and phraseology.
Operations Golden Rules
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Checking the difference between FMS DIS TO
and DME distance against the criteria applicable
for the flight phase (as defined in SOPs).
Use the correct level of automation for
the task
If the required FMS navigation accuracy criteria are
not achieved, revert from NAV mode to selected
heading mode with reference to navaids raw-data.
On highly automated and integrated aircraft, several
levels of automation are available to perform a given
task:
• FMS modes and guidance; or,
Select PF ND to ARC or ROSE mode. If no map
shift is observed, PNF may keep ND in MAP mode,
with display of speed constraints and/or altitude
constraints, for enhanced horizontal and vertical
situational awareness.
• Selected modes and guidance.
The correct level of automation depends on:
• The task to be performed:
− short-term (tactical) task; or,
One head up at all times
− long-term (strategic) task;
Significant changes to the FMS flight plan should be
performed by PNF and cross-checked by PF, after
transfer of controls, in order to maintain one head up
at all times for supervising the progress of the flight
and aircraft systems.
• The flight phase:
− enroute;
− terminal area; or,
− approach; and,
When things don’t go as expected, Take
Over
• The time available:
− normal selection or entry; or,
If the aircraft does not follow the desired vertical
flight path / lateral flight path or the selected targets,
and time does not permit analyzing and solving the
observed behavior, revert without delay from:
•
FMS guidance to selected guidance; or from,
•
Selected guidance to hand flying.
− last-minute change.
The correct level of automation often is the one the
pilot feels the most comfortable with, depending on
his/her knowledge and experience of the aircraft and
systems.
Reversion to hand-flying and manual thrust-control
may be the correct level of automation, for the
prevailing conditions.
Operations Golden Rules
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The GOLDEN RULES Card
Golden Rules for Abnormal and Emergency
Conditions
The GOLDEN RULES card has been developed to
promote and disseminate the operations Golden
Rules.
The following additional rules may assist flight crew
in their decision making when in an abnormal or
emergency condition, but also if being faced with a
condition or circumstance that is not covered by the
published procedures.
The card is provided to all trainees attending a flightcrew-training course at an Airbus Training Center
(i.e., in Toulouse, Miami and Beijing).
Understand the prevailing condition before
acting
Incorrect decisions often are the result of an
incorrect recognition and identification of the actual
prevailing condition.
Assess risks and time pressures
Take time to make time, by:
•
Delaying actions, when possible (e.g., during
takeoff and final approach); and/or,
•
Requesting entering a holding pattern or
requesting delaying vectors (as appropriate).
Review and evaluate the available options
Consider weather conditions, crew preparedness,
type of operation, airport proximity and selfconfidence when selecting the preferred option.
Include all flight crewmembers, cabin crew, ATC
and company maintenance, as required, in this
evaluation.
Consider all implications before deciding and plan
for contingencies
Figure 1
Consider all the aspects of the continuation of the
flight until landing and reaching a complete stop.
Golden Rules Card
Operations Golden Rules
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Match the response to the situation
Summary of Key Points
An emergency condition requires an immediate
action (this does not mean a rushed action) whereas
abnormal conditions may tolerate a delayed action.
Golden Rules constitute a set of key points for safe
operation under normal, abnormal and emergency
conditions.
If only one lesson were to be learned from the set of
Golden Rules, the following is proposed:
Manage workload
Adhere to the defined task sharing for abnormal /
emergency conditions to reduce workload and
optimize flight crew resources.
Whatever the prevailing conditions, always ensure
that one pilot is controlling and monitoring the
flight path of the aircraft.
Use AP-A/THR, if available, to alleviate the PF
workload.
Associated Briefing Notes
Use the correct level of automation for the task and
circumstances.
The following Briefing Notes can be referred to, for
further illustrating and developing the above
information:
Create a shared problem model with other
crewmembers by communicating
•
1.1 - Operating Philosophy - SOPs,
•
1.2 - Optimum Use of Automation,
•
1.5 - Use of Normal Checklists,
•
2.2 - CRM Issues in Approach and Landing
Accidents.
Communicate with other crewmembers to create a
shared understanding of :
•
Prevailing conditions; and,
•
Planned actions.
Regulatory References
Creating a shared model allows crewmembers to
work with a common reference towards a common
and well-understood objective.
Apply recommended procedures and other
agreed actions
•
ICAO – Human Factors Training Manual
(Doc 9683).
•
FAA – AC 60-22 – Aeronautical Decision
Making.
Understand the reasons and implications of any
action before acting and check the result(s) of each
action before proceeding with the next step.
Beware of irreversible actions (i.e., apply strict
confirmation and cross-check before acting).
Operations Golden Rules
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Approach-and-Landing Briefing Note
1.4 - Standard Calls
Introduction
Use of standard calls and acknowledgements
reduces the risk of tactical (short -term) decision
making errors (e.g., in selecting modes, setting
targets or selecting aircraft configurations).
Standard phraseology is essential to ensure effective
crew communication, particularly in today’s operating
environment, which increasingly features:
•
Two-crewmember operation; and,
•
International and worldwide contexts involving
crewmembers from different cultures and with
different native languages.
The importance of using standard calls increases
with increasing workload or flight phase criticality.
Standard calls should be practical, concise,
unambiguous and consistent with the aircraft design
and operating philosophy.
Standard calls are intended and designed to enhance
the
flightcrew
situational
awareness
(i.e., including the status and operation of aircraft
systems).
Standard calls should be included in the flow
sequence of company’ SOPs and should be
illustrated in the Flight Patterns published in the
company’ AOM or QRH (as applicable).
Standard calls may vary among:
•
Aircraft models, based upon flightdeck design
and systems interfaces; or,
•
Airlines, to suit their operating philosophy
(SOPs).
Command and response calls should be performed in
accordance with the defined PF / PNF task sharing
(i.e., task sharing for hand flying and for autopilot
operation, task sharing for normal operation and for
abnormal / emergency condition).
Statistical Data
Nevertheless, if a call is omitted by one
crewmember, the other crewmember should perform
the call, per good crew resource management (CRM)
practice.
Insufficient
horizontal
or
vertical
situational
awareness or inadequate understanding of prevailing
conditions is a causal factor in more than 50 % of
approach-and-landing accidents.
The other crewmember should accomplish the
requested command or verify the requested condition
and respond accordingly.
Use of Standard Calls
Standard calls should be defined to be alerting, to be
:
•
Clearly identified by the PF or PNF; and,
•
Distinguished from other intra-cockpit or ATC
communications.
The absence of a standard call at the appropriate
time or the absence of acknowledgement may be an
indication of a system or indication malfunction, or
may indicate a possible incapacitation of the other
crewmember.
Standard Calls
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•
Standard calls are used to:
•
Give a command (task delegation) or transfer an
information;
•
Acknowledge a command or
transfer;
•
Give a response or ask a question (feedback);
•
Callout a change of indication (e.g., a mode
transition or reversion); or,
•
Identify a specific event (e.g., crossing an altitude
or a flight level).
− ON or OFF following the name of a system is
either:
an information
•
•
a response confirming the status of the
system.
Flightcrew/ground mechanics communications;
•
Engine start sequence;
•
Specific event-markers along the takeoff phase;
•
Landing gear and slats/flaps selection (retraction
or extension);
− a command for the other pilot to check an
item;
•
Initiation, interruption, resumption and completion
of normal checklists;
Checked:
•
Initiation, sequencing, interruption, resumption
and completion of abnormal and emergency
checklists (paper or electronic checklist);
•
− a call (response) confirming that an
information has been checked at both pilot
stations;
Mode transitions and reversions (i.e., FMA
changes);
•
Changing the altimeter setting;
•
Approaching the cleared altitude or FL;
Set:
•
TCAS / TA or RA events;
− a command for the other pilot to set a target
value or a configuration;
•
PF/PNF transfer of controls;
•
Excessive -deviation of a flight parameter;
•
Specific points along the instrument approach
procedure;
•
Approaching and reaching minimums;
•
Acquisition of visual references; and,
•
Landing or go-around decision.
Check ( or Verify ):
that
an
item
has
been
Cross-check(ed):
Arm :
− a command for the other pilot to arm an
AP/FD mode (or to arm a system);
•
§
•
− a confirmation
checked;
•
a command for the other pilot to select /
deselect the related system; or,
Appropriate standard calls should be defined for the
following events:
The following generic standard calls often are used to
express a command or response:
•
§
Specific Standard Calls
Defining Generic Standard Calls
•
ON / OFF:
Engage:
− a command for the other pilot to engage an
AP/FD mode (or to engage a system);
Standard Calls
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Use of standard calls is of paramount importance for
optimum use of automation (i.e., for awareness of
arming or engagement of modes by calling FMA
changes, target selections, FMS entries, …):
•
When defining standard calls, standardization and
operational efficiency should be carefully balanced.
Summary of key points
The standard calls should trigger immediately the
question “ what do I want to fly now ? “, and thus
clearly indicates which:
Standard Calls ensure effective crew interaction and
communication.
− mode the pilot wishes to arm or engage;
and/or,
The Call / Command and the Response /
Acknowledgement are of equal importance to
guarantee a timely action or correction.
− target the pilot wishes to set.
When the pilot’s (PF) intention is clearly
transmitted to the other pilot (PNF), the standard
call will also:
Associated Briefing Notes
The following Briefing Notes can be reviewed along
with the above information in order to expand a
particular topic:
− facilitate the cross-check of the FMA and
PFD/ND, as applicable; and,
− facilitate the cross-check
between both pilots.
and
backup
•
1.1 - Operating Philosophy – SOPs,
•
1.2 - Optimum Use of Automation,
Standard calls should be defined for cockpit crew /
cabin crew communications in both:
•
1.3 - Operations Golden Rules,
•
Normal conditions (departure and arrival); and,
•
1.5 - Use of Normal Checklists,
•
Abnormal or emergency situations (e.g., cabin
depressurization,
on-ground
emergency
/
evacuation, crew incapacitation, forced landing or
ditching, etc).
•
2.3 - Effective Crew/ATC Communications,
•
2.4 - Intra-cockpit Communications –
Managing Interruptions and
Distractions.
Harmonization of Standard Calls
Regulatory references
The harmonization of standard calls across various
aircraft fleets (from the same or from different aircraft
manufacturers) is desirable but should not be an
overriding demand.
•
ICAO – Annex 6 – Operation of Aircraft, Part I –
International Commercial Air transport –
Aeroplanes, Appendix 2, 5.13.
•
Standard calls across fleets are only essential for
crewmembers
operating
different
fleets
(i.e., for communications between cockpit and cabin
or between cockpit and ground).
ICAO – Preparation of an Operations Manual
(Doc 9376).
•
JAR-OPS 1.1045 and associated Appendix 1 –
Operations Manuals – structure and contents.
Within the cockpit, pilots need to use standard calls
appropriate for the flightdeck and systems design.
Other References
•
With the exception of aircraft models with cockpit
commonality, cockpit layouts and systems are not
the same and, thus, similarities as well as
differences should be recognized alike.
Standard Calls
Page 3
U.S. National Transportation Safety Board
(NTSB) – Special Report NTSB-AAS-76-5 –
Special
Study:
Flightcrew
Coordination
Procedures in Air Carrier Instrument Landing
System Approach Accidents.
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Approach-and-Landing Briefing Note
1.5 - Normal Checklists
Introduction
Normal checklists are not read-and-do lists and
should be accomplished after performing the flow of
SOPs actions.
Strict adherence to suitable standard operating
procedures (SOPs) and associated normal
checklists is a major contribution to preventing and
reducing approach-and-landing accidents.
The correct completion of normal checklists is
essential for safe operation, particularly for takeoff
and during approach and landing.
This Briefing Note provides an overview of:
•
The scope and use of normal checklists; and,
For an effective use of normal checklists, the
following generic rules should be considered.
•
The factors and conditions that may affect the
normal flow and completion of normal checklists.
Initiating normal checklists:
Statistical Data
Normal checklists should be initiated (called) by the
pilot flying (PF) and read by the pilot not flying (PNF),
The omission of an action or an inappropriate action
is the largest primary causal factor in approach-andlanding accidents.
If the PF fails to initiate a normal checklist, the PNF
should suggest the initiation of the checklist
(by applying good CRM practice).
Omission of an action or inappropriate action is:
Normal checklists should be called in a timely
manner during low-workload periods (conditions
permitting) to prevent any rush or interruption that
could defeat the safety purpose of the normal
checklists.
•
A causal factor, along with other causal factors,
in 45 % of fatal approach-and-landing accidents;
and,
•
A factor, to some degree, in 70 % of all
approach-and-landing events.
Time and workload management (i.e., availability of
other crewmember) are key factors in the initiation
and effective conduct of normal checklists.
Use of Normal Checklists
Conducting normal checklists:
SOPs should be accomplished by recall using a
defined flow pattern for each cockpit panel; safetycritical points (i.e., primarily items related to aircraft
configuration) should be cross-checked with
reference to Normal Checklists.
Normal checklists are based on the “challenge and
response“ concept.
Critical items require response by the PF; some
less-critical items may be both challenged and
responded to by the PNF alone.
Normal checklists enhance flight safety by providing
an opportunity to confirm or correct the systems and
aircraft configuration for critical items.
Use of Normal Checklists
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To enhance communication and understanding
between crewmembers, the following standard rules
and phraseology should be used at all times:
•
Transition training and recurrent training also provide
a unique opportunity to discuss the reasons for the
rules and procedures, and to discuss the
consequences of failing to comply with them.
The responding crew member should respond to
the challenge only after having checked or
corrected the required configuration;
•
If achieving the required configuration is not
possible, the responding crewmember should
announce the actual configuration;
•
In all cases, the challenging crewmember should
wait for a positive response (and should crosscheck the validity of the response, as required)
before moving to the next item; and,
•
The PNF should verbalize the completion of the
checklist by calling “ […] checklist complete”.
Conversely, allowing a relaxed adherence to SOPs
and/or a relaxed use of normal checklists during
transition or recurrent simulator training may
encourage corresponding deviations during line
operation.
Line checks and line audits should reinforce strict
adherence to SOPs and Normal Checklists.
Factors Affecting Normal Checklists
To ensure effective compliance with published normal
checklists, it is important to understand why pilots
sometimes omit partially or completely a normal
checklist.
A320/A330/A340 families feature electronic normal
checklists (i.e., TAKEOFF and LANDING MEMO)
that allow a positive identification of :
•
Items being completed; and,
•
Items still to be performed (blue color coding).
Pilots rarely omit the performance of a normal
checklist intentionally; such a deviation from SOPs
often is the result of operational circumstances that
disrupt the normal flow of cockpit duties.
Interrupting and resuming normal checklists:
The following factors and conditions often are cited in
discussing the complete or partial non-performance
of a normal checklist:
If the flow of a normal checklist needs to be
interrupted for any reason, the PF should announce a
formal and explicit hold such as “hold (stop) checklist
at [item] “.
•
Out-of-phase time scale, whenever a factor (such
as tail wind or a system malfunction) modifies
the timescale of the approach or the occurrence
of the trigger-event for the initiation of the normal
checklist;
•
Distractions (e.g., due to intra-cockpit activities);
•
Interruptions (e.g., due to pilot / controller
communications);
•
Task saturation (i.e., inadequate multi-tasking
ability or task overload);
•
Incorrect management of priorities (i.e., absence
of decision-making model for time-critical
situations);
•
Reduced attent ion (tunnel vision) in abnormal or
high-workload conditions;
•
Incorrect CRM techniques (absence of effective
cross-check, crew coordination and/or backup);
•
Overreliance on memory (overconfidence);
An explicit call such as “resume (continue) checklist
at [item] “ should be made.
Upon resuming the normal checklist after an
interruption, the last known completed item should
be repeated - as an overlap – to prevent another item
from being omitted.
The SOPs, in the applicable FCOM and QRH,
provide type-related information.
Training Aspects
Disciplined use of SOPs and normal checklists
should begin during the transition training course,
because habits and routines acquired during
transition training have a recognized lasting effect.
Use of Normal Checklists
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•
Less-than-optimum checklist content and/or task
sharing and/or format; and,
•
Insufficient emphasis on strict adherence to
normal checklists during transition training and
recurrent training.
Regulatory references
•
ICAO – Annex 6 – Operation of Aircraft, Part I –
International Commercial Air Transport –
Aeroplanes, 4.2.5, 6.1.3 and Appendix 2, 5.10.
•
ICAO – Procedures for Air navigation Services –
Aircraft operations (PANS -OPS, Doc 8168),
Volume I – Flight Procedures (Post Amendment
No 11, applicable Nov.1/2001).
•
ICAO – Preparation of an Operations Manual
(Doc 9376).
•
ICAO – Human
(Doc 9683).
•
FAR 121.315 – Instrument and Equipment
Requirement - Cockpit Check Procedure (for
normal and non-normal conditions).
•
JAR-OPS 1.1045 and associated Appendix 1 –
Operations Manuals – Structure and Contents.
Summary of Key Points
Initiation and completing normal checklists in a
timely manner is the most effective means of
preventing the omission of actions or preventing
inappropriate actions.
Explicit calls should be defined in the SOPs for the
interruption (hold) and resumption (continuation) of a
normal checklist (i.e., in case of interruption or
distraction).
Disciplined use of normal checklists should be:
•
Highlighted at all stages of initial, transition and
line training; and,
•
Enforced at the opportunity of all checks and
audits performed during line operation.
Associated Briefing Notes
The following Briefing Notes may be reviewed in
association with the above information to complete
the overview of standard operating procedures:
• 1.1 - Operating Philosophy - SOPs,
• 1.3 - Operational Golden Rules,
• 1.4 - Standard Calls,
• 2.4 - Intra-cockpit Communications –
Managing Interruptions and
Distractions.
Use of Normal Checklists
Page 3
Factors
Training
Manual
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Approach-and-Landing Briefing Note
1.6 - Approach and Go-around Briefings
Introduction
The style and tone of the briefing play an important
role; interactive briefings – i.e., confirming the
agreement and understanding of the PNF after each
phase of the briefing – provides more effective and
productive briefings than an uninterrupted recitation
terminated by the final query “ Any question ? “.
To ensure mutual understanding and effective
cooperation among crewmembers and with ATC, indepth approach and go-around briefings should be
conducted on each flight.
Interactive briefings better fulfill an important purpose
of the briefings: to provide the PF and PNF with an
opportunity
to
correct
each
other
(e.g., confirming use of the correct and effective
approach chart, confirming correct setup of navaids
for the assigned landing runway, etc).
A thorough briefing should be conducted regardless
of:
•
How familiar the destination airport and the
approach may be; or,
•
How often the crewmembers have flown together.
Briefings should be structured (i.e., follow the logical
sequence of the approach and landing) and concise.
This Briefing Note provides generic guidelines for
conducting effective and productive briefings.
The routine and formal repetition of the same points
on each sector may become counterproductive;
adapting and expanding the briefing by highlighting
the special aspects of the approach or the actual
weather conditions and circumstances result in more
lively and effective briefings.
Statistical Data
The quality of approach and go-around briefings is
observed as a causal factor in approximately 50 % of
approach-and-landing accident, by affecting:
•
Understanding of prevailing conditions;
•
Horizontal or vertical situational awareness;
and,
•
Crew coordination.
In short, the briefing should attract the PNF’s
attention.
The briefing should therefore be conducted when the
workload and availability of the PNF permit an
effective briefing.
Any aspect that may affect normal operation
(e.g., system failures, weather conditions or other
particular conditions) should be carefully evaluated
and discussed.
Briefing Techniques
The importance of briefing techniques often is
underestimated,
although
effective
briefings
contribute to enhance crew standardization and
communication.
The briefing should help both the PF (giving the
briefing) and the PNF (receiving and acknowledging
the briefing) to understand the sequence of events
and actions, as well as the special hazards and
circumstances of the approach (i.e., by creating a
common mental model of the approach).
Approach and Go-around Briefing(s)
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Whether anticipated or not, changes in an air traffic
control (ATC) clearance, weather conditions or
landing runway require reviewing part of the initial
briefing.
Aircraft Status:
Review the aircraft STATUS, as applicable (i.e., any
failure or malfunction experienced during the flight)
and discuss the possible consequences in terms of
operation and performance (i.e., final approach speed
and landing distance).
Timeliness of Briefings
Rushing during descent and approach is a significant
factor in approach-and-landing incidents and
accidents.
Fuel Status:
Review fuel status:
To prevent any rush in initiating the descent and
increased workload in conducting the approach, the
descent preparation and the approach and go-around
briefings
typically
should
be
completed
10 minutes before reaching the top-of-descent.
•
Fuel on board;
•
Minimum diversion fuel; and,
•
Available holding fuel and time.
ATIS:
Scope of Briefings
Review and discuss the following items:
The approach and go-around briefings should cover
the following generic aspects of the approach and
landing, including a possible missed approach and a
second approach or diversion:
•
Approach conditions (i.e., weather and runway
conditions, special hazards);
•
Lateral and vertical navigation (i.e., intended use
of automation);
•
Runway in use (type of approach);
•
Expected arrival route (standard terminal arrival [
STAR ] or radar vectors);
•
Altimeter setting (QNH or QFE, as required),
-
For international operations, be aware of the
applicable altimeter setting unit (hectopascals
or inches- of-mercury);
•
Instrument approach procedure details;
•
Communications;
•
Non-normal procedures, as applicable; and,
•
•
Review and discussion of approach-and-landing
hazards.
Transition level (unless standard for the country
or for the airport);
•
Terminal weather (discuss likely turbulence, icing
or wind shear conditions and runway condition);
and,
•
Advisory messages (as applicable).
These aspects are expanded and discussed in
details in this Briefing Note.
Approach Briefing
NOTAMs:
FMS pages and ND should be used to guide and
illustrate the briefing, and to confirm the various data
entries.
Review and discuss enroute and terminal NOTAMs,
as applicable, for possible additional hazards or
airspace restrictions.
An expanded review of the items to be covered in the
approach briefing – as practical and appropriate for
the conditions of the flight – is provided hereafter.
Approach and Go-around Briefing(s)
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Top-of-descent point:
•
Visibility/RVR
applicable);
Confirm or adjust the top-of-descent point, computed
by the FMS, as a function of the expected arrival
(i.e., following the published STAR or radar vectors).
•
Descent/decision minimums:
Approach Chart:
Review and discuss the following items using the
approach chart and the FMS/ND (as applicable):
•
Designated runway and approach type;
•
Chart index number and date;
•
Minimum Safe Altitude (MSA) - reference point,
sectors and minimum sector safe altitudes;
•
•
Let-down navaid(s), frequency and
(confirm the correct setup of navaids);
•
Airport elevation;
•
Approach transitions (fixes, holding pattern,
altitude and speed constraints/restrictions,
required navaids setup);
Final approach course (and lead-in radial);
•
Terrain features (location and elevation
hazardous terrain or man-made obstacles);
•
Approach profile vi ew :
•
(and
ceiling,
as
-
MDA(H) for non-precision approaches;
-
Barometric DA(H) for CAT I ILS approaches;
or,
-
Radio-altimeter DH for CAT II and CAT III ILS
approaches.
Local airport requirement (e.g., noise restrictions
on the use of thrust reversers, etc).
Airport chart:
identifier
•
minimums
Review and discuss the following items using the
airport chart:
of
•
Runway length, width and slope;
•
Approach and runway lighting,
expected visual references;
•
Specific hazards (as applicable); and,
•
Intended turnoff taxiway.
and
other
If another airport is located in the close vicinity of the
destination airport, relevant details or procedures
should be discussed for awareness purposes.
-
Final approach fix (FAF);
-
Final descent point (if different from FAF);
-
Visual descent/decision point (VDP);
-
Missed-approach point (MAP);
-
Typical vertical speed at expected final
approach ground speed (GS); and,
-
Touchdown zone elevation (TDZE).
Use of automation:
Discuss the intended use of automation for vertical
and lateral guidance depending on FMS navigation
accuracy (only for aircraft not equipped with GPS or if
GPS PRIMARY LOST is displayed):
•
Use of FMS vertical navigation and lateral
navigation or use of selected vertical modes and
lateral modes; and,
•
Step-down approach (if a constant-angle
non-precision approach is not available or not
possible).
Missed approach :
-
Lateral and vertical navigation;
-
Speed restrictions;
-
Minimum diversion fuel;
-
Second approach (discuss the type of
approach if a different runway and/or type of
approach is envisaged) or diversion to the
alternate;
Landing and Stopping:
Discuss the intended landing flaps configuration
(if different from full flaps).
Approach and Go-around Briefing(s)
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Review and discuss the following features of the
intended landing runway:
The go-around briefing should recall briefly the
following key aspects:
•
Surface condition;
•
•
Go-around callout (i.e.,
go-around / flaps call);
Intended use of autobrake and thrust reversers;
and,
•
PF/PNF task sharing (i.e., flow of respective
actions, including use of AP, speed restrictions,
go-around altitude, parameter-excessive-deviation
calls);
•
Intended use of automation (i.e., automatic or
manual go-around, use of FMS lateral navigation
or use of selected modes for missed-approach);
•
Missed-approach lateral navigation and vertical
profile (e.g., highlighting obstacles and terrain
features, as applicable); and,
•
Intentions (i.e., second approach or diversion).
•
Expected runway turn-off
Taxi to gate:
Review and discuss:
•
The anticipated taxiways to taxi to the assigned
gate (e.g., back-track on active runway or on
parallel runway, with special emphasis on the
possible crossing of active runways, as
applicable);
•
Non-standard lighting and/or marking of taxiways;
and/or,
•
Possible work in progress on runways and
taxiways.
a
loud
and
clear
It is recommended to briefly recall the main points of
the
go-around
and
missed-approach when
established on the final approach course or after
completing the landing checklist (as deemed
practical).
As required, this review and discussion can be
delayed until after landing.
Summary of Key Points
The approach and go-around briefings should be
adapted to the conditions of the flight and focus on
the items that are relevant for the particular approach
and landing (such as specific approach hazards).
CAT II / CAT III ILS briefing:
For CAT II and CAT III ILS approaches, perform the
specific CAT II (CAT III) briefing in accordance with
company’ SOPs.
The approach and go-around briefing should include
the following ALAR-critical items:
Deviations from SOPs:
Any intended deviation from SOPs or from standard
calls should be discussed during the briefing.
Go-around Briefing
A go-around briefing should be included in the
descent -and-approach briefing, highlighting the key
points of the go-around maneuver and missedapproach, and the task sharing under normal or
abnormal / emergency conditions.
•
Minimum safe altitude;
•
Terrain and man-made obstacles features;
•
Weather and runway condition;
•
Other approach hazards, as applicable (e.g.,
visual illusions);
•
Applicable minimums (visibility or RVR, ceiling
as applicable);
Approach and Go-around Briefing(s)
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•
Applicable stabilization height (approach gate);
•
Final approach flight path angle (and vertical
speed); and,
•
Go-around altitude and missed-approach initial
steps.
Regulatory References
Associated Briefing Notes
The following Briefing Notes should be reviewed in
association with the above information for a complete
overview of the descent and approach preparation:
•
1.1 – Operating Philosophy - SOPs,
•
2.3 - Effective Crew/ATC Communications,
•
2.1 - Human Factors in Approach-andLanding Accidents,
•
2.2 - CRM Issues in Approach-and-landing
•
ICAO – Annex 6 – Operation of Aircraft, Part I –
International Commercial Air Transport –
Aeroplanes, Appendix 2, 5.16.
•
ICAO – Procedures for Air navigation Services –
Aircraft operations (PANS -OPS, Doc 8168),
Volume I – Flight Procedures (Post Amendment
No 11, applicable Nov.1/2001).
•
ICAO – Preparation of an Operations manual
(Doc 9376).
•
FAR 121.315 – Cockpit Check Procedure, for
normal and non-normal conditions.
•
JAR-OPS 1.1045 and associated Appendix 1, B
2.1 (g).
Accidents,
•
6.1 - Being Prepared to Go-around,
•
7.1 - Flying Stabilized Approaches.
Approach and Go-around Briefing(s)
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Chapter 2
Crew Coordination
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Approach-and-Landing Briefing Note
2.1 - Human Factors in Approach-and-Landing Accidents
Introduction
The following factors and conditions often are cited
in discussing deviations from SOPs:
This Briefing Note provides a summary of human
factors issues identified in approach-and-landing
accidents.
•
Task saturation (i.e., absence of multi-tasking
ability or task overload);
•
Inadequate knowledge of or failure to
understand the rule, procedure or action; this
includes:
This summary may be used either to assess:
•
Company exposure and develop corresponding
prevention strategies; or,
•
Individual exposure and develop corresponding
personal lines-of-defense.
−
training;
−
quality of wording or phrasing; and/or,
−
perception of rule or procedure or action as
inappropriate;
Statistical Data
•
Ultimately, human factors are involved in all
incidents and accidents.
Insufficient emphasis on strict adherence to
SOPs during transition training and recurrent
training;
•
Lack of vigilance (e.g., fatigue);
•
Distractions (e.g., due to cockpit activities);
•
Interruptions (e.g.,
communications);
•
Incorrect management of priorities (i.e.,
absence of decision-making model for timecritical situations);
•
Reduced attention (tunnel vision) in abnormal or
high-workload conditions;
•
Incorrect CRM techniques (i.e., for effective
cross-check, crew coordination or backup);
•
Company policies (e.g., regarding schedules,
costs, go-around and diversion events);
•
Other policies (e.g., crew duty time);
•
Personal desires or constraints (i.e., personal
schedule, focus on mission completion);
•
Complacency; and/or,
•
High time on aircraft type (i.e., overconfidence).
Whether crew-related, ATC-related, maintenancerelated, organization-related or design-related each
link of the error chain involves human beings and,
therefore, human decisions and behaviors.
Human Factors Issues in ...
Standard operating procedures (SOPs):
To ensure effective compliance with published
SOPs (and associated normal checklists and
standards calls), it is important to understand why
pilots intentionally or inadvertently deviate from rules
or standards.
Pilots rarely deviate intentionally from SOPs, in most
cases the procedure that was followed in place of
the published procedure seemed to be appropriate
for the prevailing circumstances, considering the
information available at the time.
Human Factors in Approach and Landing Accidents
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to
pilot/controller
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Use of automation:
Briefing Techniques:
Errors in using and managing automatic flight
systems and/or lack of awareness of operating
modes are observed as causal factors in more than
20 % of approach-and-landing accidents and nearaccidents.
The importance of briefing techniques often is
underestimated,
although
effective
briefings
contribute to enhance crew standardization and
communication.
The routine and formal repetition of the same points
on each sector may become counterproductive;
adapting and expanding the briefing by highlighting
the special aspects of the approach or the actual
weather conditions and circumstances of the day
result in more lively and effective briefings.
These factors can result in flying an unintended flight
path, which - if not recognized - can cause a lessthan-desired terrain separation or a CFIT.
The following common errors in handling auto flight
systems can increase the risk of approach-andlanding accidents:
•
Inadvertent selection of an incorrect mode;
•
Failure to verify the selected mode by reference
to the flight mode annunciator (FMA);
•
Failure to arm a mode when required (e.g., failure
to arm the localizer or approach mode, when
cleared for LOC or ILS interception);
•
Failure to select a required guidance target
(e.g., failure to set the ILS final approach course);
•
Inadvertent change of a guidance target
(i.e., changing the speed target instead of
changing the selected heading);
•
The briefing should help both the PF (giving the
briefing) and the PNF (receiving and acknowledging
the briefing) to understand the sequence of events
and actions, the safety key points, special hazards
and circumstances of the approach.
An interactive briefing fulfills two important goals of
the briefing: provide the PF and the PNF with an
opportunity to:
Selection of an incorrect altitude and failure to
confirm the selection on the primary flight display
(PFD);
•
Selection of the altitude target to any altitude
below the final approach intercept altitude during
approach;
•
Preoccupation with FMS programming during a
critical flight phase, with consequent loss of
situational awareness; and/or,
•
The briefing should attract the attention of the PNF.
•
Interaction with automation;
•
Overreliance on automation; and/or,
•
Lack of crew crosscheck.
•
Share a common
approach.
mental
model
of
the
Effective communication is achieved when our
mental process for interpreting the information
contained in a message accommodates the
message being received.
This mental process can be summarized as follows:
The Briefing Note 1.3 - Operations Golden Rules,
addresses aspects that are considered frequent
causal factors in approach and landing accidents,
such as:
Lack of situational / positional awareness;
Correct each other; and,
Crew/ATC Communications:
Failure to monitor the automation, using raw data.
•
•
•
How do we perceive the message ?
•
How do we reconstruct
contained in the message ?
•
How do we link the information to an objective
or an expectation ? and,
•
What bias or error is introduced in this process?
the
information
Crew Resource Management (CRM) researches
highlight the importance of the context and
expectations in this mental process.
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The following factors may affect the correct
understanding of communications:
•
High workload;
•
Fatigue;
•
Non-adherence to “sterile cockpit” rule;
•
Distractions;
•
Interruptions; and/or,
•
Conflicts and pressures.
•
Missing or misinterpreting an ATC instruction
(i.e., possibly resulting in a traffic conflict or
runway incursion);
•
Omitting an action and failing to detect and
correct the resulting abnormal condition or
configuration, if interrupted during a normal
checklist (e.g., altimeter setting); and/or,
•
Leaving
uncertainties
unresolved
(e.g.,
regarding an ATC instruction or an abnormal
condition).
This may result in :
•
Incomplete communications;
Altimeter setting and altitude deviation issues:
•
Omission of call sign or use of an incorrect call
sign;
The incorrect setting of the altimeter reference often
is the result of one or more of the following factors:
•
Use of nonstandard phraseology; and/or,
•
•
High workload;
Failure to listen or respond.
•
Inadequate pilot/system interface;
Intra-crew Communications:
•
Incorrect pilot/controller communication;
Interruptions and distractions in the cockpit break
the flow pattern of ongoing cockpit activities
(i.e., actions or communications), such as:
•
Deviation from normal task sharing;
•
Interruptions and distractions; and/or,
•
Absence
of
crewmembers.
•
SOPs;
•
Normal checklists;
•
Communications (i.e., listening, processing,
responding );
•
Monitoring tasks; and/or,
•
Problem solving activities.
backup
between
Strict adherence to defined task sharing (for normal
or abnormal/emergency conditions) and correct use
of normal checklists are the most effective lines-ofdefense against altimeter setting errors.
The diverted attention resulting from the interruption
or distraction usually leaves the flight crew with the
feeling of being rushed and being faced with
competing or preempting tasks.
Rushed and unstabilized approaches:
The following circumstances, factors and errors
often are cited when discussing rushed and
unstabilized approaches:
Being confronted with concurrent task demands, the
natural human tendency leads to performing one
task to the detriment of another.
•
Fatigue, regardless of short/medium-haul or
long-haul operation,
This highlights the need for developing
countermeasures to restore the level of
vigilance and alertness for the descent,
approach and landing;
Unless mitigated by adequate techniques in order to
set priorities, this disruption and lapse of attention
may result in:
•
effective
Not monitoring the flight path (possibly resulting
in an altitude or course deviation or a controlled
flight into terrain);
•
Pressure of flight schedule (e.g., making up for
takeoff delay);
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Any
crew-induced
or
controller-induced
circumstance resulting in insufficient time to
plan, prepare and execute a safe approach;
•
Incorrect assessment of crosswind limit for
prevailing runway conditions;
•
Incorrect assessment of landing distance:
This includes accepting requests from ATC for:
−
flying higher and/or faster than desired;
and/or,
−
flying shorter routings than desired;
•
Insufficient ATC awareness of crew or aircraft
capability to accommodate a last-minutechange;
•
Late takeover from automation (e.g., in case of
AP failing to capture the GS, usually due to crew
failing to arm the approach mode);
•
Lack of awareness of tail wind component;
•
Incorrect anticipation of aircraft deceleration
characteristics in level-flight or on a 3-degree
glideslope;
•
Belief that the aircraft will be stabilized at the
stabilization height or shortly thereafter;
•
PNF excessive confidence in the PF
achieving a timely stabilization;
•
− following a malfunction affecting
configuration or braking capability;
Failure to recognize excessive parameterdeviations or to remember the excessiveparameter-deviation criteria;
•
•
− for prevailing wind and runway conditions; or,
in
Runway excursions and overruns:
The following factors are recurrent in runway
excursions and overruns (i.e., highlighting human
factors involving controllers, flightcrew and
maintenance personnel alike):
•
Inaccurate weather information on:
Captain (when PNF) taking over control and
landing following the call or initiation of a goaround by the First Officer (as PF);
•
Late takeover from automation, when required
(e.g., late take over from autobrake in case of
system malfunction);
•
Inoperative equipment not accounted for per
MEL (e.g., one or more brake being
inoperative); and/or,
•
Undetected thrust asymmetry (i.e., forward /
reverse asymmetric thrust condition).
The following human factors often are cited in
discussing events involving adverse wind /
crosswind conditions:
Visual illusions during the acquisition of visual
references or during the visual segment.
No go-around decision, when warranted;
•
Adverse wind / crosswind landing:
PF/PNF excessive reliance on each other in
calling excessive deviations or in calling
go-around; and/or,
•
the
•
Reluctance to recognize changes in landing
data over time (e.g., wind direction shift, wind
velocity change or wind gustiness increase);
•
Seeking any evidence to confirm the initial
information and initial options (i.e., reluctance to
change pre-established plans);
•
Reluctance to divert to an airport with less
crosswind conditions; and/or,
•
Lack of time to observe, evaluate and control
the aircraft attitude and flight path in a highly
dynamic situation.
Summary of key points
− surface wind;
Addressing Human Factors issues in approach-andlanding incidents and accidents is an effort that
must include:
− runway condition; and/or,
•
Defined company safety culture and policies;
− wind shear;
•
Related prevention strategies;
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•
Robust standard operating procedures;
•
Effective CRM practices; and,
•
Personal lines-of-defense.
Regulatory References
Associated Briefing Notes
The following Briefing Notes can be referred to as a
complement to the above information, to amplify or
expend a specific aspect, as desired:
•
ICAO – Annex 6 – Operation of Aircraft, Part I –
International Commercial Air Transport –
Aeroplanes, Appendix 2, 15.
•
ICAO – Procedures for Air navigation Services –
Aircraft operations (PANS-OPS, Doc 8168),
Volume I – Flight Procedures (Post Amendment
No 11, applicable Nov.1/2001).
•
ICAO – Accident Prevention Manual (Doc
9422).
•
ICAO – Human Factors Training Manual
(Doc 9683).
•
ICAO – Human Factors Digest No 8 – Human
Factors in Air Traffic Control (Circular 241).
•
1.1 – Operating Philosophy - SOPs,
•
1.3 - Operations Golden Rules,
•
1.4 - Standard Calls,
•
1.5 - Use of Normal Checklists,
•
1.6 – Approach and Go-around Briefings,
•
•
2.2 - CRM Issues in Approach and Landing
Accidents,
FAR 121.406, 121.419, 121.421 or 121.422 CRM Training for pilots, flight attendants and
aircraft dispatchers.
•
JAR-OPS 1.945, 1.955 or 1.965 - CRM
Training.
•
2.3 - Effective ATC/Crew Communications,
•
2.4 - Intra-cockpit Communications –
Managing Interruptions and
Distractions in the Cockpit,
•
3.1 - Altimeter Setting – Use of radio
Altimeter,
•
3.2 - Altitude Deviations,
•
7.1 - Flying Stabilized Approaches,
•
8.1 - Preventing Runway Excursions and
Overruns.
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Approach-and-Landing Briefing Note
2.2. - CRM Issues in Approach-and-Landing Accidents
Introduction
The flightcrew is considered to be the last line-ofdefense but is also the last link in the error chain.
Approach-and-landing accidents involve the entire
range of CRM and Human Factors issues.
The following discussion is a focused but limited
overview of this broad subject.
Company
therefore:
safety
culture
and
policies
should
•
Support the implementation of CRM practices;
The minimum content of CRM training is defined by
regulations and airlines should consider additional
CRM training to account for specific requirements,
such as multi-cultural flight crews and different
areas of operation.
•
Facilitate the mitigation of organizational factors;
and,
•
Identify and address precursors of potential
incidents or accidents.
Statistical data
International Cultural Factors
CRM issues have been identified as circumstantial
factors in more than 70 % of approach-and-landing
incidents or accidents.
As more operators access to global international
operation with multi-nationality crewmembers,
cross-cultural issues should become an important
part of a customized CRM training.
Because CRM practices are a key factor in
flightcrew adherence to and performance of normal
and non-normal procedures and in the interaction
with automated systems, CRM issues are involved
to some degree in every incident or accident.
The discussion of cross-cultural factors should
include:
•
Understanding differences between race and
culture;
•
Highlighting the importance of cultural and
national sensitivities;
•
Promoting the use of standard phraseology as a
common working language.
General
The flight crew’s contribution to an incident or
accident often is considered to be what the flight
crew did or did not do.
Leadership
CRM concepts and techniques enhance effective
cross monitoring and backup by each crewmember.
The role of the pilot-in-command (PIC) in complex
and demanding situations should be emphasized
during CRM training.
Company Culture and Policies
This includes, for example, approaches with
marginal weather conditions or abnormal /
emergency conditions that are beyond the scope of
published procedures.
It should be recognized that many factors
associated with accidents are embedded in the
global aviation- system organization.
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Teamwork
Inquiry and Advocacy
The captain’s role and attitude in opening the line of
communication with the first officer and cabin crew
is of prime importance for setting the flight deck
atmosphere and ensuring effective:
Flightcrews often are faced with ATC requests that
are either:
•
Human relations
communications);
•
Teamwork (e.g., allowing the authority and duty
for the first officer to voice any concern as to the
progress of the flight and overall safety); and,
•
Crew coordination,
backup.
(e.g.,
effective
mutual
•
Not understood (e.g., being assigned an altitude
below the sector MSA, when the minimum
vectoring altitude is not published); or,
•
Challenging (e.g., being requested to fly higher
and/or faster than desired or to take a shorter
routing than desired).
intra-crew
monitoring
Flight crews should not accept such instructions
without requesting clarification or being sure that
they can comply safely with the ATC instructions.
and
Performing a pre-flight briefing that includes
the flight crew and cabin crew establishes the basis
for effective teamwork.
Briefings
Flight attendants may hesitate to report technical
occurrences to flight crew (i.e., because of cultural
aspects, company policies or intimidation).
Effective and interactive briefings enhance crew
coordination and preparedness for planned actions
or unexpected occurrences, by creating a common
mental model of the approach.
To overcome this reluctance, the implementation
and interpretation of the sterile cockpit rule (as
applicable) should be discussed during cabin crew
CRM training and recalled by the captain during the
pre-flight briefing.
Time Management
Taking time to make time, developing multi-tasking
ability and ensuring task prioritization are essential
factors in staying ahead of the aircraft.
Briefing Note 1.3 - Operations Golden Rules
describes the various steps of a typical tacticaldecision-making model, for use in time-critical
situations.
Assertiveness
Approach-and-landing incidents and accidents
illustrate that if an option (e.g., performing a goaround) has not been prepared, flight crew may lack
the mental resources needed to:
•
•
Interruptions and Distractions
Make the required decision (i.e., initiate the goaround); or,
Coping with unexpected distraction, disturbance and
contingency in the cockpit requires the use of
techniques to lessen the effects of any disruption in
the flow of on-going cockpit activities.
Correctly conduct the required maneuver
(i.e., flying the published missed-approach).
Fatigue, overconfidence or reluctance to change a
prepared plan often are the probable causes for a
lack of assertiveness (assessment of situation) and
decision-making.
Flight crews should “ expect the unexpected ”.
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Effective flightcrew decision-making requires a joint
evaluation of possible options prior to proceeding
with an agreed-upon decision and action.
Error Management
Error-management training and techniques should
be considered at company level and at personal
level.
The effect of pressures (e.g., delays, company
policies, ATC requests, etc) that may affect how the
crew conducts the flight and makes decisions
should be acknowledged by the industry.
Approach-and-Landing Briefing Notes list and
discuss the relevant influence factors (i.e., error
factors) in order to identify or suggest the
development of associated:
•
Company prevention strategies; and,
•
Personal lines-of-defenses.
Nevertheless, eliminating all pressures is not a
realistic objective. Thus, company accidentprevention strategies, CRM techniques and
personal lines-of-defense should be used to cope
effectively with such pressures.
The most critical aspect in discussing error
management is not the initial error or deviation but
the failure to detect this error or deviation, by mutual
monitoring and backup.
The use of a tactical-decision-making model for
time-critical situations often is an effective technique
to lessen the effects of pressures.
Risk Management
Several tactical-decision-making models (usually
based on memory aids or on sequential models)
have been developed and should be discussed
during CRM training.
For the flight crew, risk management consists in
assessing the effects of potential hazards on the
safe conduct of the flight and in finding ways to
avoid these hazards or to minimize their effects.
All tactical-decision-making models share the
following phases (refer to Briefing Note 1.3 –
Operations Golden Rules ) :
Risk management should be seen as a balanced
management of priorities.
Risk management sometimes is described as
opposing:
•
•
A sure inconvenience (e.g., associated with a
go-around or a diversion); against,
A probable-only risk (e.g., risk associated with
an unstabilized approach to a long and dry
runway).
A practical and safety-oriented method of risk
management is entirely contained in the concept
and techniques of tactical-decision-making (refer to
Briefing Note 1.3 – Operations Golden Rules ).
Decision Making
•
Recognizing the prevailing condition;
•
Assessing short term and
consequences on the flight;
•
Evaluating available options and procedures;
•
Deciding the course of actions;
•
Taking actions in accordance with the defined
procedures and applicable task-sharing;
•
Evaluating and monitoring action results; and,
•
Resuming standard flying duties.
long
term
Postponing a decision until that option is no more
considered or no longer available is a recurring
pattern in approach-and-landing accidents.
SOPs sometimes are perceived as limiting the
flightcrew’s judgement and decision.
The concepts of next-target and approach-gate are
intended to act as benchmarks for supporting a
timely decision-making process.
Without denying the captain’s emergency authority,
SOPs are safeguards against biased decisionmaking.
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Other CRM Aspects
Summary of Key Points
The following CRM aspects may be involved in
approach-and-landing incidents or accidents:
CRM practices optimize the performance of the
entire crew (i.e., including flight crew and cabin
crew, and maintenance personnel).
•
Spatial disorientation (i.e., physiological illusions
and/or visual illusions);
CRM skills effectively:
•
Complacency when operating at a familiar
airport (e.g., home base); or,
•
Relieve the effects of pressures, interruptions
and distractions;
•
Overconfidence (e.g., high time on aircraft type);
•
Provide benchmarks for timely decision-making;
and,
•
Inadequate anticipation (i.e., inability to “ stay
ahead of the aircraft “);
•
Provide safeguards for effective errormanagement, thus minimizing the effects of
working errors.
•
Inadequate preparation to respond to changing
situations or to an abnormal / emergency
condition, by precise planning and use of all
available technical and human resources
(i.e., by “ expecting the unexpected “);
Associated Briefing Notes
The following Briefing Notes provide expanded
information to complement the above discussion:
•
Crewmembers personal factors; and/or,
•
Absence of specific training of instructors and
check airmen to evaluate the CRM performance
of trainees and line pilots.
Factors Affecting CRM Practice
The following organizational or personal factors may
adversely affect the effective implementation of
CRM practices:
•
1.1 - Operating Philosophy - SOPs,
•
1.2 – Optimum use of Automation,
•
1.3 - Operations Golden Rules,
•
1.4 - Standard Calls,
•
1.5 – Use of Normal Checklists,
•
Company culture and policies;
•
1.6 - Approach and Go-around Briefings,
•
Belief that actions or decisions are correct,
although they deviates from the applicable
standards;
•
2.1 - Human Factors in Approach-andLanding Accidents,
•
Effect
of
fatigue
and
countermeasures to restore
vigilance and alertness; and/or,
•
2.3 - Effective Crew/ATC Communications,
•
2.4 - Intra-cockpit Communications –
Managing Interruptions and
Distractions in the Cockpit.
•
absence
the level
of
of
Reluctance to accept the influence of human
factors and CRM issues in approach-andlanding incidents or accidents.
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Regulatory References
•
ICAO – Annex 6 – Operation of Aircraft, Part I –
International Commercial Air Transport –
Aeroplanes, Appendix 2, 5.15, 5.21 and 5.22.
•
ICAO – Procedures for Air Navigation Services
– Rules of the Air and Air Traffic Services
(PANS-RAC, Doc 9432).
•
ICAO – Procedures for Air navigation Services –
Aircraft operations (PANS-OPS, Doc 8168),
Volume I – Flight Procedures (Post Amendment
No 11, applicable Nov.1/2001).
•
ICAO – Accident Prevention Manual (Doc
9422).
•
ICAO – Human Factors Training Manual
(Doc 9683).
•
ICAO – Human Factors Digest No 8 – Human
Factors in Air Traffic Control (Circular 241).
•
FAR 121.406, 121.419, 121.421 or 121.422 CRM Training for pilots, cabin crew and aircraft
dispatchers.
•
FAA – AC 60-22 – Aeronautical Decision
Making.
•
JAR-OPS 1.945, 1.955 or 1.965 - CRM
Training.
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Approach-and-Landing Briefing Note
2.3 - Effective Pilot/Controller Communications
Introduction
Remark
Until controller / pilot data link communication
(CPDLC) comes into widespread use, air traffic
control
(ATC)
will
depend
upon
voice
communications that are affected by various factors.
Although pilot / controller communications are not
limited to the issuance and acknowledgement of
clearances, this Briefing Note refers primarily to
clearances because this provides a convenient
example to illustrate most discussion topics.
Communications between controllers and pilots can
be improved by the mutual understanding of each
other’s operating environment.
Pilot / Controller Responsibilities
This Approach-and-Landing Briefing Note provides
an overview of various factors that may affect pilot /
controller communications.
The responsibilities of the pilot and controller
intentionally overlap in many areas to provide
redundancy.
This Briefing Note may be used to develop a
company awareness program for enhancing flight
pilot / controller communications.
This shared responsibility is intended
compensate for failures that might affect safety.
Statistical Data
The Pilot / Controller Communication Loop
Incorrect or incomplete pilot / controller
communications is a causal or circumstantial factor
in many approach-and-landing events.
The pilot / controller communication loop supports
the safety and redundancy of pilot / controller
communications ( Figure 1 ).
Incorrect or inadequate:
The pilot / controller communication loop constitutes
a confirmation / correction process that ensures the
integrity of communications.
•
ATC instructions (such as radar vectors);
•
Weather or traffic information; and/or,
•
Advice/service in case of emergency,
to
Whenever adverse factors are likely to affect
communications, strict adherence to this closed
loop
constitutes
a
line-of-defense
against
communication errors.
are causal factors in more than 30 % of approachand-landing accidents.
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ATC Clearance
Acknowledge or
Correct
Transmit
Listen
Pilot’s
Readback
Controller’s
Hearback
Listen
Transmit
Figure 1
The Pilot / Controller Communication Loop
Achieving
Effective
Communications:
Obstacles and Lessons Learned
Human
factors
communication
Pilots and controllers are involved equally in the air
traffic management system.
Effective communication is achieved when our
mental process for interpreting the information
contained in a message accommodates the
message received.
Achieving effective radio communications involves
many factors that should not be considered in
isolation.
aspects
in
effective
This mental process can be summarized as follows:
Many factors are closely interrelated, and more than
one cause usually is involved in a breakdown of the
communication loop.
The following provides an overview and discussion
of factors involved in effective pilot / controller
communications
•
How do we perceive the message ?
•
How do we reconstruct
contained in the message ?
•
How do we link this information to an objective
or to an expectation ? and,
•
What bias or error is introduced in this process?
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Crew resource management (CRM) researches
highlight the importance of the context and
expectations in this process. Nevertheless,
expectations may introduce either a positive or
negative bias in the effectiveness of the
communication.
The structure and construction of the initial and
subsequent message(s) should support this context
by:
Workload, fatigue, non-adherence to the sterile
cockpit rule, distractions, interruptions, conflicts and
pressure are among the factors that may affect
adversely pilot / controller communications and
result in:
•
Incomplete communications;
•
Omission of call sign or use of an incorrect call
sign;
•
Use of nonstandard phraseology;
•
Failure to listen or respond; and,
•
Failure to effectively implement the confirmation
/ correction loop.
•
Following the chronological
sequence of actions;
•
Grouping instructions and numbers related to
each action; and,
•
Limiting the number of instructions in the
transmission.
order
of
the
The intonation, the speed of transmission and the
placement and duration of pauses may positively or
adversely affect the correct understanding of a
communication.
Mastering the Language
CRM studies show that language differences are a
more fundamental obstacle to safety in the cockpit
than cultural differences.
In response to a series of accidents involving
language skills as a causal factor, an effort has
been initiated to improve the English-language skills
of pilots and controllers worldwide.
Language and Communication
No individual is expected to speak any language,
even his/her own native language, correctly and in a
standard way. Acknowledging this fact is a first step
towards developing or enhancing communication
skills.
Nevertheless, even pilots and controllers for whom
English is the native language may not understand
all communications spoken in English, because of
regional accents or dialects.
The language of pilot / controller communications is
intended to overcome this basic shortcoming.
Language
differences
generate
communication difficulties worldwide.
The first priority of any communication is to
establish an operational context, by using markers
and modifiers to define the following elements of the
context:
significant
•
Purpose - clearance, instruction, conditional
statement or proposal, question or request,
confirmation;
Controllers using both English ( for communication
with international flights ) and the country’s native
language ( for communication with domestic flights )
prevent pilots from achieving the desired level of
situational awareness ( because of loss of “partyline communications” ).
•
When - immediately, anticipate / expect;
Use of Nonstandard Phraseology
•
What and how - altitude (i.e., climb, descend,
maintain), heading (i.e., left, right) , airspeed;
and,
Use of nonstandard phraseology is a major obstacle
to voice communications.
•
Where - (i.e., before or at […] waypoint).
Standard phraseology is intended to be easily and
quickly recognized.
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Pilots and controllers expect each other to use
standard phraseology.
Lack of Readback (use of “Roger“ for
acknowledgement) or Incomplete Readback
Standard phraseology helps lessen the ambiguities
of spoken language and thus guarantees a common
understanding among speakers:
The term Roger often is misused, thus decreasing
the pilot’s and the controller’s situational awareness:
•
Of different native languages, or,
•
Of the same native language but who use or
understand words differently (e.g., regional
accents or dialects).
Nonstandard phraseology or the omission of key
words may change completely the meaning of the
intended message, resulting in potential conflicts.
For example, any message containing a “number“
should indicate whether the number refers to an
altitude, a heading or an airspeed. Including key
words prevents an erroneous interpretation and
allows an effective readback / hearback.
•
Pilot may use Roger to acknowledge a message
containing numbers (instead of a formal
readback), thus preventing effective hearback
and correction by the controller; or,
•
Controller may use Roger to acknowledge a
message requiring a specific answer (e.g., a
positive confirmation or correction, such as
acknowledging a pilot’s statement that an
altitude or speed restriction cannot be met).
Failure of Correct an Erroneous Readback
( hearback errors )
Most pilots perceive the absence of an
acknowledgement or correction following a
clearance readback as an implicit confirmation of
the readback.
Pilots and controllers might use non-standard
phraseology with good intentions; however standard
phraseology
minimizes
the
potential
for
misunderstanding.
The lack of acknowledgement by the controller
usually is the result of frequency congestion,
requiring the controller to issue clearances and
instructions to several aircraft.
Building Situational Awareness
Radio communications ( including party-line
communications ) contribute to build the pilot’s and
the controller’s situational awareness.
Uncorrected erroneous readback (known as
hearback errors) may cause deviations from the
assigned altitude or noncompliance with altitude
restrictions or with radar vectors.
Flight
crew
and
controller
may
prevent
misunderstandings by providing each other with
advance information.
A deviation from a clearance or instruction may not
be detected until the controller observes the
deviation on his/her radar display.
Frequency Congestion
Less-than-required vertical or horizontal separations
(and near midair collisions) or runway incursions
usually are the result of hearback errors.
Frequency congestion significantly affects the
correct flow of communications during approach
and landing phases at high-density airports, this
requires enhanced vigilance by pilots and by
controllers.
Perceiving What Was Expected or Wanted
(not what was actually said)
The bias of expectation can affect the correct
understanding of communications by pilots and
controllers.
Omission of Call Sign
Omitting the call sign or using an incorrect call sign
jeopardizes an effective readback / hearback.
This involves perceiving what was expected or
wanted and not what was actually said.
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The bias of expectation can lead to:
•
•
Taking a Clearance or Instruction Issued to
Another Aircraft
Transposing the numbers contained in a
clearance (e.g., an altitude or FL) to what was
expected, based on experience or routine;
This usually occurs when two aircraft with similarsounding call signs are on the same frequency and
are likely to receive similar instructions or if the call
sign is blocked by another transmission.
Shifting a clearance or instruction from one
parameter to another (e.g., perceiving a
clearance to maintain a 280-degree heading as
a clearance to climb / descend and maintain
FL 280).
When pilots of different aircraft with similarsounding call signs omit the call sign on readback,
or when simultaneous readback are made by both
pilots, the error may go unnoticed by the pilots and
the controller.
Failure to Seek Confirmation (when a message
is not understood)
Filtering Communications
Misunderstandings may include half-heard words or
guessed-at numbers.
Because of other flight deck duties, pilots tend to
filter communications, listening primarily to
communications that begin by their aircraft call sign
and not hearing most other communications.
The potential for misunderstanding numbers
increases when a given ATC clearance contains
more than two instructions.
For workload reasons, controllers also may filter
communications (e.g., not hearing or responding to
a pilot readback, while engaged in issuing
clearances/instructions to other aircraft or ensuring
internal coordination).
Failure to Request Clarification (when in doubt)
Reluctance to seek confirmation or clarification may
cause pilots to either:
•
Accept an inadequate instruction (over-reliance
on ATC); or,
•
Define by themselves
interpretation.
To maintain situational awareness, this filtering /
selection process should be adapted, according to
the flight phase, for more effective listening.
the most probable
For example, whenever occupying an active runway
(e.g., while back-tracking or holding into position) or
when conducting a final approach to an assigned
runway, the pilot’s should listen and give attention to
all communications related to this runway.
Failing to request clarification may cause flight crew
to believe erroneously that they have received an
expected clearance (e.g., clearance to cross an
active runway).
Timeliness of Communications
Failure to Question an Incorrect or Inadequate
ATC Instruction
Deviating from an ATC clearance may be required
for operational reasons (e.g., performing a heading
or altitude deviation for weather avoidance, inability
to meet a restriction).
Failing to question an incorrect or inadequate
instruction may cause a crew to accept an altitude
clearance below the sector MSA or a heading that
places the aircraft near obstructions.
Both the pilot and the controller need time to
accommodate this deviation; therefore ATC should
be notified as early as possible to obtain a timely
acknowledgement.
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Similarly, when about to enter a known non-radarcontrolled flight information region (FIR), contacting
the new air route traffic control center (ARTCC),
approximately 10 minutes before reaching the FIR
boundary, may prevent misunderstandings or lessthan-required separations.
Pilot / Controller Communications in
Emergency Situations
In an emergency, the flightcrew and the controller
should adopt a clear and concise communications
pattern, as suggested hereafter.
Blocked Transmissions
( simultaneous communications )
Flight crew
The standard ICAO phraseology Pan Pan – Pan
Pan – Pan Pan or Mayday – Mayday – Mayday
(i.e., depending on the criticality of the prevailing
condition) should be used to alert the controller and
trigger an appropriate response.
Blocked transmissions often are the result of not
immediately releasing the push-to-talk switch after a
communication.
An excessive pause in a message (i.e., holding the
push-to-talk switch while preparing the next item of
the transmission) also may result in blocking part of
the response or part of another message.
Controllers
Controllers should recognize that, when faced with
an emergency situation, the flight crew’s most
important needs are:
Simultaneous transmission of communications by
two stations (i.e., two aircraft or one aircraft and
ATC) results in one of the two (or both)
transmissions being blocked and unheard by the
other stations (or being heard as a buzzing sound or
as a squeal).
The absence of readback (from the pilot) or the
absence of hearback acknowledgement (from the
controller) should be considered as an indication of
a blocked transmission and, thus, prompt a request
to repeat or confirm the information.
with
ATC
on
Time;
•
Airspace; and,
•
Quiet.
The controller’s response to the emergency
situation could be patterned after the ASSIST
memory aid, proposed below:
Blocked transmissions are responsible for many
altitude deviations, missed turnoffs and takeoffs and
landings without clearances.
Communicating
Events
•
•
− Ensure that the reported emergency is well
understood and acknowledged.
Specific
•
The following events or encounters should be
reported as soon as practical to ATC, stating the
nature of the event or encounter, the actions taken
and the flight crew’s further intentions (as
applicable):
•
TCAS resolution advisory (RA) events;
•
Severe turbulence encounter;
•
Volcanic ash encounter;
•
Windshear or microburst encounter; and,
•
GPWS/TAWS terrain avoidance maneuver.
Acknowledge :
Separate :
− Establish and maintain separation with other
traffic and/or terrain.
•
Silence :
− Impose silence on your control frequency, if
necessary; and,
− Do not delay or disturb urgent cockpit action
by unnecessary transmissions.
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•
•
Inform :
•
Alertness to request clarification or confirmation,
when in doubt;
− Inform your supervisor and other sectors,
units and airports, as appropriate.
•
Readiness to question an incorrect clearance or
an inadequate instruction;
Support :
•
Preventing simultaneous transmissions;
•
Adapting listening of party-line communications
as a function of the flight phase; and,
•
Adopting
clear,
concise
and
adapted
communications in an emergency situation.
−
•
Getting to Grips with
Approach-and-Landing Accidents Reduction
Provide maximum support to the flight crew.
Time :
− Allows flight crew sufficient time to manage
the emergency situation.
In addition, Operations Manual and/or SOPs should
define the following company policies:
Awareness and Training Program
A company awareness and training program on pilot
/ controller communications should involve both
ATC personnel and pilots (e.g., during meetings and
simulator sessions) to promote a mutual
understanding of each other’s working environment,
including:
•
Modern flight decks (e.g., FMS reprogramming)
and ATC equipment (e.g., elimination of primary
returns such as weather returns on synthetic
radar displays);
•
Operational
requirements
(e.g.,
aircraft
deceleration
characteristics,
performance,
limitations); and,
•
Procedures
(e.g., CRM).
(e.g.,
SOPs)
and
•
Primary language for use with ATC and in the
cockpit; and
•
Use of headsets below 10 000 ft.
Associated Briefing Notes
The following Briefing Notes may be reviewed to
expand the discussion on Effective Pilot / controller
Communications:
practices
Special emphasis should be placed on pilot /
controller communications and task management
during emergency situations.
•
2.1 - HF Issues in Approach-and-Landing
Accidents,
•
2.2 - CRM Issues in Approach-and Landing
Accidents,
•
2.4 - Intra-cockpit Communications –
Managing Interruptions and
Distractions,
•
7.1 - Flying Stabilized Approaches.
Summary of Key Points
Regulatory References
Although achieving effective pilot / controller
communications requires a global approach, the
importance of the following key points should be
emphasized:
•
Reference
regarding
pilot
/
controller
communications can be found in many international
and national publications, such as:
Understanding of pilots and controllers
respective
working
environments
and
constraints;
•
Disciplined use of standard phraseology;
•
Strict adherence to the pilot / controller
communication loop (i.e., confirmation /
correction process);
•
ICAO – Annex 6 – Operation of Aircraft, Part I –
International Commercial Air Transport –
Aeroplanes, Appendix 2, 5.15.
•
ICAO – Procedures for Air Navigation Services
– Rules of the Air and Air Traffic Services
(PANS-RAC, Doc 4444).
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•
ICAO – Procedures for Air navigation Services –
Aircraft operations (PANS-OPS, Doc 8168),
Volume I – Flight Procedures (Post Amendment
No 11, applicable Nov.1/2001).
•
ICAO - Annex 10 – Volume II / Communication
procedures – Chapter 5 / Aeronautical Mobile
Service;
•
ICAO - Manual of Radiotelephony (Doc 9432).
•
ICAO – Human Factors Training Manual
(Doc 9683).
•
ICAO – Human Factors Digest No 8 – Human
Factors in Air Traffic Control (Circular 241).
•
The
respective
national
Information Publications (AIPs);
•
National publications, such as :
Aeronautical
− the U.S. Federal Aviation Administration
(FAA) Aeronautical Information Manual
(AIM) – Official guide to basic flight
information and air traffic control procedures,
− the guide of Phraseology for Radiotelephony
Procedures issued by the French Direction
de la Navigation Aerienne (DNA),
− the Radiotelephony Manual issued by the
U.K. Civil Aviation Authority (Civil Aviation
Publication - CAP 413).
•
FAR 121.406, 121.419, 121.421 or 121.422 CRM Training for pilots, cabin crew and aircraft
dispatchers.
•
FAA AC 60-22 – Aeronautical Decision Making.
•
JAR-OPS 1.945, 1.955 or 1.965 - CRM
Training.
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Approach-and-Landing Briefing Note
2.4. - Intra-Cockpit Communications
Managing Interruptions and Distractions in Cockpit
Introduction
Statistical Data
The omission of an action or an inappropriate action
is the most frequent causal factors in approach and
landing accidents.
The following causal factors, frequently observed in
approach-and-landing accidents, often are the result
of interruptions or distractions in the cockpit.
Interruptions (e.g., due to ATC communications)
and distractions (e.g., due one cabin attendant
entering the cockpit) occur frequently; some cannot
be avoided, some can be minimized or eliminated.
Omission
of
action
inappropriate action
The following aspects should be considered to
assess company exposure and personal exposure
and to develop prevention strategies and lines-ofdefense to lessen the effects of interruptions and
distractions in the cockpit:
•
% of
Events
Factor
Recognize the potential sources of interruptions
and distractions;
or
72 %
Inadequate crew coordination,
cross-check and back-up
63 %
Insufficient horizontal or vertical
situational awareness
52 %
•
Understand their effect on the flow of cockpit
duties;
•
Reduce interruptions and distractions ( e.g. by
adopting the Sterile Cockpit Rule );
Inadequate
or
insufficient
understanding of prevailing
conditions
48 %
•
Develop prevention strategies and lines-ofdefense to minimize the exposure to
interruptions and distractions; and,
Slow or delayed action
45 %
Develop techniques for lessen the effects of
interruptions and distractions.
Incorrect or incomplete pilot /
controller communications
33 %
•
Table 1
Effects of Distractions and Interruptions
in Approach-and-Landing Accidents
Intra-Cockpit Communications – Managing Interruptions and Distractions in Cockpit
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Being faced with concurrent task demands, the
natural human tendency is to perform one task to
the detriment of another.
Types of Interruptions and Distractions
Interruptions and distractions in the cockpit may be
subtle or be momentary, but they can be disruptive
to the flight crew.
Unless mitigated by adequate techniques, the
disruption and lapse of attention may result in:
Interruptions or distractions can be classified in
three main categories, as follows:
•
•
Not monitoring the flight path (possibly resulting
in an altitude or course deviation or a controlled
flight into terrain);
•
Missing or misinterpreting an ATC instruction
(possibly resulting in traffic conflict or runway
incursion);
•
Omitting an action and failing to detect and
correct the resulting abnormal condition or
configuration (e.g., interruption during the
reading of a normal checklist); or,
•
Experiencing task overload (i.e., being “ behind
the aircraft ” ).
Communications :
− receiving the final weights while taxiing; or,
− a flight attendant entering the cockpit;
•
Head-down work :
− reading the approach chart; or,
− programming the FMS; and,
•
Responding to an abnormal condition or to
an unanticipated situation :
− system malfunction; or,
− Traffic collision avoidance system (TCAS)
traffic advisory (TA) or resolution advisory
(RA).
Reducing Interruptions and Distractions
Acknowledging that flight crew may have control
over some interruptions / distractions and not over
some others is the first step in developing
prevention strategies and lines-of-defense.
Minor disruptions (e.g., a minor equipment
malfunction) can turn a routine flight into a
challenging event.
Actions that may be controlled (e.g. SOP’s actions,
initiation of normal checklists, …) should be
scheduled during periods of less likely disruption, to
prevent interference with actions that cannot be
controlled (e.g. ATC communications or flight
attendant interruptions).
Effect of Interruptions or Distractions
The primary effect of interruptions or distractions is
to break the flow of ongoing cockpit activities
(i.e., actions or communications), this includes :
•
SOPs;
•
Normal checklists;
•
Communications (i.e., listening, processing,
responding);
•
Monitoring tasks (i.e., systems monitoring,
PF/PNF mutual cross-check and back-up); and,
•
Problem solving activities.
Adhering to the Sterile Cockpit Rule can largely
reduce interruptions and distractions.
The Sterile Cockpit Rule reflects the requirement of
U.S. FAR – Part 121.542 :
•
The diverted attention resulting from the interruption
/ distraction usually leaves the flight crew with the
feeling of being rushed and faced with competing /
preempting tasks.
“ No flight crewmember may engage in, nor may
any pilot in command permit any activity during
a critical phase of flight which could distract any
flight crewmember from the performance of his
or her duties or which could interfere in any way
with the proper conduct of those duties “.
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For the purpose of this requirement, an “ activity “
includes:
The implementation of the sterile cockpit rule by
cabin crew creates two challenges:
•
•
How to identify the 10,000 ft limit ?
•
How to identify occurrences that warrant
breaking the sterile cockpit rule ?
“…, engaging in non-essential conversation
within
the
cockpit
and
non-essential
communication between the cabin and cockpit
crews, … “.
Several methods for signaling to the cabin crew
the crossing of the 10,000 feet limit have been
evaluated (e.g., using the all-cabin-attendants call or
a public-address announcement).
The term “ critical phases of flight “ encompasses:
•
“ all ground operations involving taxi, takeoff
and landing, and all other flight operations
below 10,000 feet, except cruise flight “.
Whatever method is used, it should not create its
own distraction to the flight crew.
In the FARs understanding, the 10,000 feet limit is
defined as 10,000 ft MSL.
The following occurrences are considered to
warrant breaking the sterile cockpit rule:
When operating to or from a high elevation airport, a
definition based on 10 000 ft AGL might be
considered as more appropriate.
Complying with the sterile cockpit rule during taxiout and taxi-in requires extra discipline as taxi
phases often provide a relief between phases of
high workload and concentration.
Interruptions / distractions during taxi is the main
causal factor in takeoff accidents and runway
incursions.
The sterile cockpit rule has been adopted by nonU.S. operators and is also covered (although in less
explicit terms) in the JAR-OPS 1.085(d)(8).
The sterile cockpit rule should be implemented with
good common sense in order not to break the
communication line between flight crewmembers or
between cabin crew and flight crew.
Adherence to the Sterile Cockpit Rule should not
affect:
•
Fire, burning odor or smoke in the cabin;
•
Medical emergency;
•
Unusual noise or vibration ( e.g. evidence of
tailstrike );
•
Engine fire ( tail pipe or nacelle torching flame ),
•
Fuel or fluid leakage;
•
Emergency exit or door unsafe condition
( although this condition is annunciated to the
flight crew );
•
Extreme ( local ) temperature changes;
•
Evidence of deicing problem;
•
Cart stowage problem;
•
Suspicious, unclaimed bag or package; and,
•
Any other condition, as deemed relevant by the
senior cabin crewmember (purser).
•
Use of good CRM practices by flight crew; and,
•
Communication of emergency or safety related
information by cabin crew;
This list may need to be adjusted for local
regulations or to suit each individual company
policy.
The U.S. FAA acknowledges that it is better to
break the sterile cockpit rule than to fail to
communicate.
Cabin crewmembers may hesitate to report
technical occurrences to the flight crew (e.g.,
because of cultural aspects, company policies or
intimidation).
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To overcome this reluctance, the implementation
and interpretation of the sterile cockpit rule should
be discussed during cabin crew CRM training, and
recalled by the captain during the pre-flight briefing.
The following lines-of-defense address the three
families of cockpit disruptions and, thus, prevent or
minimize the interference of competing or
preempting tasks:
•
Analyses of aviation safety reports indicate that the
most frequent violations of the sterile cockpit rule
are caused by the following:
•
Non-flight-related conversations;
•
Distractions by cabin crewmembers;
•
Non-flight-related radio calls; and/or,
•
Non-essential public-address announcements.
− keep intra-cockpit communications brief clear
and concise; and,
− interrupt conversations when approaching the
defined next target or the next altitude
restriction / constraint.
•
− plan long head-down tasks in low-workload
periods; and,
A high level of interaction and communication
between flight crewmembers, and between flight
crew and cabin crews, constitutes the first line of
defense to reduce errors.
− announce that you are going “head-down”.
•
The foundations for an effective line of
communication and interaction between all flight
crewmembers and cabin crewmembers should be
embedded in:
Company policies;
•
SOPs;
•
CRM training; and,
•
Leadership role of the pilot in command
(commander).
Sterile Cockpit Rule;
•
Operations Golden Rules; and,
•
Standard Calls.
Responding to an abnormal condition or to
an unanticipated situation:
− keep the AP engaged to decrease workload,
unless otherwise required;
− adhere to PF / PNF task sharing for abnormal
/ emergency conditions (PNF should maintain
situational awareness, monitor and back-up
the PF); and,
− give particular attention to normal checklists,
because handling an abnormal condition may
disrupt the normal flow of SOPs actions,
SOPs actions and normal checklists are
initiated based on events (triggers); in case of
disruption these events may go unnoticed
and the absence of the usual trigger may be
interpreted incorrectly as action complete or
checklist complete.
Strict adherence to the following operating policies
provides safeguards to minimize disruptions or to
lessen their effects:
•
Head-down work ( FMS programming or chart
review ) :
− define task sharing for FMS programming or
reprogramming depending on the level of
automation being used and on the flight
phase (SOPs);
Prevention Strategies and Lines-of-defense
•
Communications :
The above lines of defense minimize the flight crew
exposure to disruptions caused by interruptions and
distractions.
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Managing Interruptions and Distractions
Summary of key points
Because some interruptions and distractions may
be subtle and insidious, the first priority is to
recognize and identify the disruption.
Interruptions and distractions usually result from the
following factors:
•
Pilot / controller or intra-cockpit communications
(i.e., including flight crew / cabin crew
communications);
Identify :
•
Head-down work; or,
−
•
Responding to an abnormal condition or an
unanticipated situation.
The second priority is to re-establish situational
awareness, as follows:
•
•
Ask :
−
•
What was I doing?
Prevention strategies and lines-of-defense should
be developed to minimize interruptions and
distractions and to lessen their effects.
Where was I interrupted?
Decide/Act :
Strict adherence to the following standards is the
most effective company prevention strategy and
personal line-of-defense:
− What decision or action shall I take to get
“back on track” ?
The following decision-making-process should be
applied:
•
Prioritize :
Operations Golden Rules provide
guidelines for task prioritization :
clear
Fly, Navigate, Communicate and Manage, in
that order.
•
•
SOPs;
•
Operations Golden Rules;
•
Standard calls;
•
Sterile cockpit rule (as applicable); and,
•
Recovery techniques such as:
− Identify – ask – decide – act; and,
− Prioritize – plan – verify.
Plan :
Some actions may have to be postponed until
time and conditions permit. Asking for more time
(e.g. from the ATC or from the other
crewmember) will prevent being rushed in the
accomplishment of competing actions.
Associated Briefing Notes
The following Briefing Notes provide expanded
information to supplement this discussion:
In other words, take time to make time.
•
1.3 - Operations Golden Rules,
Verify :
•
1.4 – Standard Calls,
Using SOPs techniques (i.e., concept of next
target, action blocks, event triggers and normal
checklists), ensure that the action(s) that had
been postponed have been duly accomplished.
•
1.5 - Use of Normal Checklists,
•
2.1 - Human Factors in Approach-andLanding Accidents,
Finally, if the disruption interrupt the course of a
normal checklist or abnormal checklist, an explicit
hold should be verbalized to mark the interruption of
the checklist and an explicit command should be
used for resuming the checklist.
•
2.2 - CRM Issues in Approach-and-landing
Accidents,
•
2.3 - Effective Crew/ATC Communications.
•
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Regulatory references
•
ICAO - Preparation of an Operations manual
(Doc 9376).
•
ICAO – Human Factors
(Doc 9683).
•
ICAO – Human Factors Digest No 8 – Human
Factors in Air Traffic Control (Circular 241).
•
FAR 121.406, 121.419, 121.421 or 121.422 CRM Training.
•
FAR 121.542 – Sterile cockpit rule.
•
JAR-OPS 1.945, 1.955 or 1.965 - CRM Training.
•
JAR-OPS 1.085(d)(8) – Sterile cockpit.
Training Manual
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Chapter 3
Altimeter and Altitude Issues
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Approach-and-Landing Briefing Note
3.1 - Altimeter Setting - Use of Radio Altimeter
Introduction
QNH or QFE ?
Operators with international routes are exposed to
different standards in terms of:
The use of QNH for operations below the transition
level / altitude eliminates the need for changing the
altimeter-setting:
•
Altitude measurement (i.e., feet or meters);
•
Altitude reference setting-units (i.e., hectopascal
or inch-of-mercury, QNH or QFE); and,
•
Environmental conditions (i.e., atmospheric
pressure changes and/or low OAT operation).
•
During the approach and landing; and,
•
During the missed approach, as required.
When QFE is used for the approach, the altimeter
must be change to QNH for the missed-approach,
unless the missed-approach procedure is defined
with reference to QFE.
This Briefing Note provides a review and discussion
of the following aspects, highlighting the lessons
learned from approach-and-landing incidents and
accidents:
Some operators set the altimeter to QFE in areas of
operation where the ATC and the majority of other
operators use QNH. This requires adequate SOPs
for altimeter-setting and for conversion of assigned
altitudes to heights.
•
Barometric-altimeter reference ( QNH or QFE );
•
Use of different units for altitude measurement
(i.e., feet versus meters) and altimeter setting
(i.e., In.Hg versus hPa);
•
Setting of baro-altimeter bug and radio-altimeter
DH;
•
Radio-altimeter callouts; and,
Operators with international routes are exposed to
the use of different altimeter setting units:
•
Low-OAT operation.
•
Hectopascals ( hPa ), previously referred to as
milibars ( mb ),
•
Inches-of-mercury (in. Hg).
Altimeter-setting Units
Statistical Data
Deviation from the intended vertical flight profile
(caused by omission of an action or by an incorrect
action) is frequently observed during line checks and
audits.
When in.Hg is used for altimeter setting, unusual
barometric pressures such as:
The lack of situational awareness, particularly the
lack of vertical situational awareness, is a causal
factor in 50 % of approach-and-landing accidents
(this includes most accidents involving CFIT).
•
28.XX in.Hg (i.e., an unusually low pressure); or,
•
30.XX in.Hg (i.e., an unusually high pressure),
may go undetected when listening to the ATIS or
ATC, resulting in a more usual 29.XX altimeter
setting being set.
Altimeter Setting – Use of Radio Altimeter
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A 1.00 in.Hg discrepancy in the altimeter setting
results in a 1000-ft error in the intended (actual)
altitude, as illustrated by Figure 1 ( Figure 1,
Figure 2 and Figure 3 assume a 2000 ft airfield
elevation and a 4000 ft indicated altitude).
In Figure 3, an actual QNH of 991 hPa was
mistakenly set on the altimeter as 29.91 in.Hg
(equivalent to 1012 hPa ), resulting in the actual
altitude / height being 640 ft lower than indicated.
In Figure 1, the actual QNH is an usually low 28.XX
in.Hg but the altimeter setting was mistakenly set to
a more usual 29.XX in.Hg, resulting in the actual
altitude / height being 1000 ft lower than indicated:
Actual height
1360 ft AFL
Indicated altitude
4000 ft
Actual altitude
3360 ft
Sea level
QNH 991 hPa
Actual height
1000 ft AFL
Indicated altitude
4000 ft
Actual altitude
3000 ft
Sea level
QNH 28.XX in.Hg
Field elevation
2000 ft
Altimeter error
640 ft
Altimeter setting 29.91 in.Hg ( 1012 hPa )
Field elevation
2000 ft
Figure 3
Altimeter error
1000 ft
Altimeter setting 29.XX
Setting the altimeter reference
Figure 1
In order to eliminate or lessen the risk associated
with the use of different altimeter-setting units or with
the use of unusual (low or high) altimeter-setting
values, the following rules should be used by
controllers (when recording the ATIS message or
when transmitting the altimeter-setting) and by pilots
(when reading back the altimeter-setting):
In Figure 2, the actual QNH is an usually high 30.XX
in.Hg but the altimeter setting was mistakenly set to
a more usual 29.XX in.Hg, resulting in the actual
altitude / height being 1000 ft higher than indicated.
•
Indicated altitude
4000 ft
Actual altitude
5000 ft
QNH 30.XX in.Hg
A transmission such as “altimeter setting six
seven” can be interpreted as 28.67, 29.67 or
30.67 in.Hg, or as 967 hPa.
Actual height
3000 ft AFL
Indicating the altimeter-setting unit prevents
confusion or allows detection and correction of a
previous error.
Field elevation
2000 ft
Altimeter setting 29.XX
Sea level
All digits as well as the unit (e.g., inches or
hectopascals) should be indicated.
Altimeter error
1000 ft
•
Figure 2
When using inches of mercury (in.Hg), “low”
should precede an altimeter setting of 28.XX
in.Hg and “high” should precede an altimeter
setting of 30.XX in.Hg.
Confusion between altimeter setting units (i.e. hPa
versus in.Hg) leads to similar errors in the actual
altitude and actual height above airfield elevation.
The U.S. FAA accepts this practice, if deemed
desirable by regional or local air traffic services.
Altimeter Setting – Use of Radio Altimeter
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The incorrect setting of the altimeter reference often
is the result of one or more of the following factors:
•
High workload;
•
Deviation from normal task sharing;
•
Interruptions and distractions; and,
•
Absence of effective cross-check and backup
between crewmembers.
Setting of Barometric-altimeter Bug and
Radio-altimeter DH
The barometric-altimeter bug and of the radioaltimeter DH should be set in line with Airbus
Industrie’ SOP’s or company’ SOPs.
Approach
Baro Bug
RA DH
Visual
MDA/DA of
instrument
approach
or
200 ft
Adherence to the defined task sharing (for normal or
abnormal / emergency conditions) and the use of
normal checklists are the most effective lines-ofdefense against altimeter setting errors.
200 ft above
airfield
elevation
Use of Metric Altimeter
Non-ILS
Using metric altitudes in certain countries (such as
the Commonwealth of Independent States [CIS] and
The People’s Republic of China) also requires
adapted procedures for setting the selected altitude
on the FCU and the use of metric altimeters
(or conversion tables) for reading the altitude in
meters.
MDA
ILS CAT I
DA
Reset of Altimeter Setting in Climb or
Descent
ILS CAT II
Note 2
The transition altitude / flight level can be either:
ILS CAT III
DA
With DH
Note 2
ILS CAT III
TDZ altitude
•
Fixed for a given airport (as indicated in the
approach chart); or,
•
200 ft
Note 1
No RA
DA
Fixed for the whole country ( e.g. FL 180 in the
United States );
200 ft
Note 1
ILS CAT I RA
•
Note 1
RA DH
RA DH
With no DH
Variable, depending on QNH (as indicated in the
ATIS message).
Table 1
(Table based on use of QNH)
Depending on the airline’s / flight crew’s usual area
of operation, changing from fixed transition altitudes /
FL to variable transition altitudes / FL may result in
a premature or late setting of the altimeter reference.
Note 1 :
The RA DH may be set (e.g., at 200 ft) only for
terrain awareness purposes. Using the RA DH
should be discussed in the approach briefing.
An altitude constraint (expressed in terms of FL in
climb or expressed in terms of altitude in descent)
may advance or delay the change of the altimeter
reference and cause crew confusion.
For all approaches - except CAT I with RA, CAT II
and CAT III ILS approaches - the approach
MINIMUM callout is based on the barometricaltimeter bug set at the MDA(H) or DA(H).
Altimeter Setting – Use of Radio Altimeter
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ote 2 :
CAT III DA, or the CAT I DA in readiness for a
possible reversion to CAT I minimas.
Whenever, the temperature deviates significantly
from the standard temperature, the indicated altitude
correspondingly deviates from the true altitude, as
follows:
•
Radio-altimeter Callouts
Extreme high temperature :
− the true altitude is higher than the indicated
altitude,
Radio-altimeter callouts can be either:
•
Announced (verbalized) by the PNF or the Flight
Engineer; or,
•
Automatically generated by a synthesized voice.
•
Extreme low temperature :
− the true altitude is lower than the indicated
altitude, thus creating a lower than anticipated
terrain separation and a potential obstacleclearance hazard.
Callouts should be tailored to the airline’ operating
policy and to the type of approach.
To enhance the flight crew’s terrain awareness, a
callout “ Radio altimeter alive “, should be
announced by the first crewmember observing the
radio altimeter activation at 2500 ft height AGL.
For example, when performing an ILS approach with
a published 2000 ft minimum glide-slope
interception-altitude and a – 40 ° C OAT, the
minimum glide-slope interception altitude should be
increased by 480 ft.
The radio altimeter reading should then be included
in the instrument scanning for the remainder of the
approach.
True altitude
Given atmospheric pressure
( pressure altitude )
Radio altimeter readings below obstacle clearance
levels listed below, should alert the flight crew:
•
Initial approach : 1000 ft AGL;
•
Intermediate approach (or minimum
vectoring altitude) : 500 ft AGL;
•
Final approach (non-precision approaches with
defined FAF) : 250 ft AGL.
radar
Indicated
altitude
3000 ft
2000 ft
1520 ft
2000 ft
1000 ft
Note : The radio altimeter indicates the aircraft
current height above the ground (height AGL) and
not the height above the airfield elevation.
High OAT
Standard OAT
Low OAT
Figure 4
Unless the airport features high close-in terrain, the
radio-altimeter reading should reasonably agree with
the height above airfield elevation (obtained by direct
reading of the altimeter if using QFE or by
computation if using QNH).
Effect of OAT on True Altitude
The ICAO PANS-OPS, Volume I, provides altitude
corrections to be added to the published minimum
safe altitudes (heights).
Low OAT Operation
The temperature correction (i.e., correction to be
added to the indicated altitude) depends on the
aerodrome surface temperature and on the desired
true altitude (height) above the elevation of the
altimeter-setting source.
In a standard atmosphere, the indicated altitude
reflects the true altitude above the mean sea level
(MSL) and therefore provides a reliable indication of
terrain clearance.
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Flying into a low temperature area has the same
effect as flying into a low-pressure area; the aircraft
is lower than the altimeter indicates.
ICAO PANS-OPS does not provide altitude
corrections for extreme high temperatures;
the temperature effect on the true altitude should not
be ignored when planning for a constant-angle nonprecision approach (i.e., to maintain the required
flight path angle and/or vertical speed).
These effects are summarized and illustrated in
Table 2, featuring a well-known aviation golden rule:
From
To
Atmospheric
Pressure
High
Low
OAT
Warm
Cold
Summary of key points
Altimeter-setting errors result in a lack of vertical
situational awareness; the following key points
should be emphasized to minimize altimeter-setting
errors and to optimize the use of the barometricaltimeter bug and radio-altimeter DH:
Look
out
below
•
Awareness of altimeter setting changes due to
prevailing weather conditions (extreme cold or
warm fronts, steep frontal surfaces, semipermanent or seasonal low pressure areas);
The pilot is responsible for performing this
correction, except when under radar control in a
radar vectoring area; in this case, the controller
normally is responsible for terrain clearance,
including accounting for the cold temperature
correction.
•
Awareness of the altimeter setting unit in use at
the destination airport;
•
Awareness of the anticipated altimeter setting,
using two independent sources for cross-check
(e.g., METAR and ATIS messages);
Nevertheless, the operator and/or pilot should
confirm this responsibility with the air traffic services
of the country of operation.
•
Effective PF/PNF crosscheck and backup;
•
Adherence to SOPs for:
Table 2
The temperature correction on altitude affects the
following published altitudes, which therefore should
be increased under low OAT operation:
− reset of barometric-altimeters in climb and
descent, for example:
!
in climb : at the transition altitude; and,
!
in descent : when cleared to an altitude;
•
MEA, MSA;
•
Transition routes altitude;
•
Procedure turn altitude (as applicable);
•
FAF altitude;
− altitude callouts;
•
Step-down altitude(s) and MDA(H) during a nonprecision (non-ILS) approach;
− radio-altimeter callouts; and,
•
OM crossing altitude during an ILS approach;
and,
− setting of barometric-altimeter bug and radioaltimeter DH.
•
Waypoint crossing altitudes during a GPS
approach flown with vertical navigation.
− use of standby-altimeter to crosscheck main
altimeters;
Altimeter Setting – Use of Radio Altimeter
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Associated Briefing Notes
The following Briefing Notes also refer to altimetersetting and altitude issues:
•
1.1 - Operating Philosophy – SOPs,
•
2.3 - Effective Crew/ATC Communications,
•
2.4 - Intra-Cockpit Communications –
Managing Interruptions and
Distractions,
•
3.2 - Altitude Deviations.
•
•
ICAO Annex 6 – Procedures for Air Navigation
Services – Rules of the Air and Air Traffic
Services (PANS-RAC, Doc 4444).
•
ICAO Annex 6 – Procedures for Air navigation
Services – Aircraft Operations (PANS-OPS, Doc
8168), Volume I – Flight procedures - Part VI –
Altimeter Setting Procedures - Chapter 3 - New
table of temperature corrections to be added to
the indicated altitude when operating in low OAT
conditions.
The new Part VI – Chapter 3 will be effective in
Nov.2001 and will replace and supersede the
current Chapter 3 of Part III.
Regulatory references
•
•
ICAO Annex 3 – Meteorological Service for
International Air navigation, Chapter 4.
ICAO Annex 5 – Units of Measurement to be
used in Air and Ground Operations, Table 3-4,
3.2.
ICAO Annex 6 – Operations of Aircraft, Part I –
International Commercial Air transport –
Aeroplane, 6.9.1 c) and Appendix 2, 5.13.
•
Preparation
(Doc 9376).
•
Manual of radiotelephony (Doc 9432).
•
Human Factors Training Manual (Doc 9683).
•
Human Factors Digest No.8 – Human Factors in
Air Traffic Control (Circular 241).
•
FAA - Draft AC 91-XX - Altimeter Errors at Cold
Temperatures.
Altimeter Setting – Use of Radio Altimeter
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Approach-and-Landing Briefing Note
3.2 - Altitude Deviations
Introduction
Factors Involved in Altitude Deviations
Altitude deviations may result in substantial loss of
vertical separation and/or horizontal separation,
which could cause a midair collision.
Altitude deviations usually result from one of the
following causes:
Traffic avoidance maneuvers, if required, usually
result in injuries to passengers and crewmembers
(particularly to cabin crewmembers).
This Briefing Note provides an overview
the factors involved in altitude deviations.
of
•
Misunderstanding the assigned altitude;
•
Use of an incorrect altimeter setting;
•
Failure to level-off at the assigned altitude; or,
•
Failure to reach or maintain the assigned
altitude (or altitude restriction) at the point or
time assigned by ATC.
This document can be used for stand-alone reading
or as the basis for the development of an airline’s
altitude awareness program.
Altitude deviations always are the result of a
breakdown in either:
Statistical Data
•
An analysis by the U.S. FAA and by US Airways
indicates that:
•
•
the pilot / system interface :
− altimeter setting, use of autopilot, monitoring
of instruments and displays; or,
Approximately 70 % of altitude deviations are
the result of a breakdown in the pilot/controller
communication loop; and,
•
the pilot / controller interface :
− communication loop.
Nearly 40 % of altitude deviation events affect
the critical pair constituted by FL 100 / FL 110
(or 10 000 ft / 11 000 ft).
Altitude deviations occur as the result of one or a
combination of the following conditions:
•
Defining an Altitude Deviation
The controller assigns an incorrect altitude, or
reassigns a FL after the aircraft has been
cleared to an altitude;
An altitude deviation is defined by regulations as a
deviation from the assigned altitude (or flight level)
equal to or greater than 300 ft.
Altitude Deviations
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General:
Pilot/controller
communication
breakdown
(mainly readback / hearback errors), e.g.:
An altitude awareness program should enhance the
monitoring role of the PF and PNF by stressing the
importance of:
− Controller transmits an incorrect altitude,
the pilot does not readback and the controller
does not challenge the absence of readback;
− Pilot understands and readback an incorrect
altitude but controller does not hear back and
does not correct the crew readback; or,
•
Stating (verbalizing) intentions and actions,
when they are different from expectations (e.g.,
delayed climb or descent, management of
altitude or speed restrictions); and,
•
Backing up each other.
− Pilot accepts an altitude clearance intended
for another aircraft (confusion of callsigns);
Communications:
•
Pilot understands and reads back the correct
altitude or FL, but select an incorrect altitude or
FL , e.g. because of :
Breakdown in the pilot/controller communication
loop includes:
− confusion of numbers with an other element
of the message (e.g., speed, heading or flight
number);
− expectation / anticipation of another altitude
or FL;
− interruption / distraction; or,
− breakdown in crew crosscheck and backup;
•
Autopilot fails to capture the selected altitude;
•
Absence of response to the altitude alert aural
and visual warnings, when in hand flying; or,
•
Incorrect go-around procedure and maneuver.
•
Readback / hearback errors ( this risk is greater
when one crewmember does not monitor radio
communications because of other duties such
as listening to the ATIS or being involved in
company communications or passengeraddress announcements );
•
Blocked transmissions; or,
•
Confusion of call signs.
The following recommendations (discussed and
expanded in Briefing Note 2.3 - Effective Pilot /
can
enhance
Controller
Communications)
communications and raise the level of situational
awareness of pilots and controller:
•
Be aware that readback / hearback errors
involve may the pilot and the controller :
− The pilot may be interrupted or distracted
when listening to a clearance, confuse similar
callsigns, forget an element of the instruction
or be subject to the bias of expectation when
understanding or when reading back the
instruction ( this bias usually is referred to as
wishhearing );
Altitude Awareness Program
The development and implementation of altitude
awareness programs by several airlines have
reduced significantly the number of altitude
deviations.
− The controller may also confuse similar
callsigns, be distracted by other radio or
landline telephone communications or be
affected by blocked transmissions or high
workload.
To address the main causes of altitude deviations,
an altitude awareness program should include the
following aspects.
Altitude Deviations
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•
•
Getting to Grips with
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Use standard phraseology for clear and
unambiguous pilot / controller and intra-cockpit
communications.
•
Monitor / supervise the operation of AP for
correct level-off at the cleared altitude and for
correct compliance with altitude or time
restrictions (constraints);
Standard phraseology is the common basis for
pilots and controllers; this common language
allows an easier detection and correction of
errors.
•
Plan tasks that prevent attentive listening to
radio communications (such as copying the
ATIS, company calls, and passengers-address
announcements) during periods of less ATC
communication.
•
When one crewmember cannot monitor the
ATC frequency because of other duties or
because leaving the cockpit, the other
crewmember should :
Use of an adapted phraseology to increase the
controller situational awareness, e.g.:
− When leaving an altitude, announce:
Leaving […] for […]; or,
− Acknowledge receiving
controls, as applicable;
Leaving […] and climbing / descending to
[…];
the
radio
and
− Check the radio volume to ensure adequate
reception of ATC calls;
The call leaving … should be performed only
when a vertical speed of 500 ft/mn has been
established and the altimeter positively shows
the departure from the previous altitude or
FL;
− Give an increased attention to listening /
confirming / reading back (because of the
momentary absence of backup ); and,
− Brief the other crew member when he/she
returns, highlighting any relevant new
information and any change in the ATC
clearance or instructions.
This recommendation takes a particular
importance when descending in a holding
pattern;
− Use of two separate methods for expressing
certain altitudes – one one thousand feet, that
is eleven thousand feet; and,
Altitude-setting procedures:
The following techniques should be considered for
enhancing standard operating procedures (SOPs):
− Preceding each number by the corresponding
flight parameter (i.e., FL, heading, speed),
e.g., descend to Flight Level two four zero
instead of descend to two four zero.
•
When receiving an altitude clearance, set the
cleared altitude value immediately in the
selected altitude window (even before readback,
if deemed more suitable due to workload);
•
Ensure that the altitude selected is crosschecked by both crewmembers (e.g., each crew
member should verbalize what he or she heard
and then point to the selected altitude window to
confirm that the correct value has been set);
Task prioritization and task sharing:
•
The following guidelines and recommendations
should be considered for optimum prioritization of
tasks and task sharing:
Ensure that the cleared altitude is above the
sector minimum safe altitude; and,
•
When under radar vectoring, be aware of the
applicable minimum vectoring altitude for the
sector or positively request confirmation of an
altitude clearance below the sector MSA.
•
•
If doubt exists about a clearance, request
confirmation from ATC, do not attempt to guess
an instruction or clearance based on flight deck
discussion.
Reduce non-essential tasks during climb and
descent ( in addition to the sterile cockpit rule,
some operators consider the last 1000 ft before
reaching any assigned altitude as a sterilecockpit period );
Altitude Deviations
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Callouts:
•
Use standard calls to increase the PF / PNF
situational awareness, to ensure an effective
backup and challenge, and detect a previous error
on the assigned / cleared altitude or FL:
Failing to question the unusual (e.g. bias of
expectation or routine on a familiar SID or
STAR) and/or,
•
Interpreting subconsciously a request to slow
down to 250-kt as a clearance to descend to
FL 100.
•
Modes changes on FMA and changes of targets
on PFD/ND;
•
Leaving [...] for […] , when a 500 ft/mn vertical
speed has been established; and altimeter
indicates departure from the previous altitude;
and,
•
One to go ;
Transition Altitude / Level
As indicated in Briefing Note 3.1 - Altimeter
Setting – Use of radio Altimeter, the transition
altitude / flight level can be either:
One thousand to go “; or,
•
Fixed for the whole country ( e.g. FL 180 in the
United States);
•
Fixed for a given airport (as indicated in the
approach chart); or,
•
Variable as a function of QNH (as indicated in
the ATIS message).
[…] for […],
when within 1000 ft from the cleared altitude or
FL.
Depending on the airline’s / flight crew’s usual area
of operation, changing from fixed transition
altitudes/FL to variable transition altitudes/FL may
result in a premature or late change of the altimeter
setting.
When within 1000 ft from the cleared altitude / FL or
from an altitude restriction (constraint):
•
PF should concentrate on instruments scanning
(one head in); and,
•
PNF should watch outside for traffic, if in VMC
(one head out).
An altitude constraint (expressed in terms of FL in
climb or expressed in terms of altitude in descent)
may advance or delay the change of altimeter
setting and cause crew confusion.
Flight Level or Altitude Confusion
In countries operating with reference to the QFE,
when below the transition altitude or FL, the
readback should indicate the altimeter reference
(i.e., QFE).
Confusion between FL 100 and FL 110 (or between
10 000 ft / 11 000 ft) is usually the result of the
combination of two or more of the following factors:
•
Readback / hearback error because of similar
sounding phrases;
Altitude Deviations in Holding Patterns
•
Absence of standard phraseology :
In holding patterns controllers rely on pilots
maintained the assigned altitude or to descend to
the new cleared altitude.
− ICAO : FL one zero zero / FL one one zero;
− U.K. NATS: FL one hundred / FL one one
zero;
•
The overlay of aircraft tags on the controller’s radar
display does not allow the immediate detection of an
impending traffic conflict.
Mindset leaning to focus only on “one zero” and
thus
to
more
easily
understand
“10 000 feet”;
Controllers, therefore, assume that a correctly
readback clearance will be correctly complied with.
Altitude Deviations
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Secondary surveillance radar’s (SSR) provide
conflict alerts but no resolution advisory; accurate
and clear pilot / controller communications are
essential when descending in a holding pattern.
The TCAS (ACAS) is an effective safeguard to
minimize the consequences of altitude deviations.
Two separate holding patterns may be controlled by
the same controller, on the same frequency.
•
Setting the altimeter-reference on barometric
altimeters; and,
The following communication rules are, therefore,
important when in a holding pattern:
•
Selecting the cleared altitude or FL on the FCU.
Altitude deviations can be prevented by strict
adherence to adequate SOPs, this includes:
•
Do not take a communication intended for an
other aircraft (by confusion of similar callsigns);
•
Prevent / minimize the risk of blocked
transmission, in case of simultaneous readback
by two aircraft with similar callsigns or
simultaneous transmissions by the pilot and the
controller; and,
The following Briefing Notes refer to altimeter
setting and altitude issues:
•
1.1 - Operating Philosophy - SOPs,
Announce leaving [FL or altitude] only when the
vertical speed indicator and the altimeter reflect
the departure from the previous altitude.
•
1.3 - Operations Golden Rules,
•
1.4 - Standard Calls,
•
2.3 - Effective Pilot / Controller
Communications,
An altitude awareness program should be
emphasized during transition and recurrent training
and during line checks.
•
Blame-free reporting of altitude deviation events
should be encourage to broaden the understanding
of causal and circumstantial factors resulting in
altitude deviations.
2.4 - Intra-crew Communications –
Managing Interruptions and
Distractions,
•
3.2 - Altimeter Setting – Use of radio
Altimeter.
•
Associated Briefing Notes
Summary of Key Points
The following safety key points should be promoted:
•
Adhere to the pilot / controller readback /
hearback process (communication circle);
•
Crosscheck and backup each other to ensure
that the altitude selected is the cleared altitude
received;
•
Cross-check that the cleared altitude is above
the sector minimum safe altitude (unless crew is
aware of the applicable minimum vectoring
altitude for the sector);
•
Monitor instruments and automation when
reaching the cleared altitude or FL; and,
•
In VMC, apply the technique one head inside /
one head out when reaching the cleared altitude
or FL.
Altitude Deviations
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Regulatory references
•
ICAO Annex 6, Parts I, II and III, Sections II and
III (amended in 1995) for discouraging the use
of three-pointer and drum-pointer altimeters.
•
ICAO Annex 6, Operation of Aircraft, Part I –
International Commercial Air Transport –
Aeroplanes, 4.2.6, 6.9.1 c) and Appendix 2,
5.13, 5.15.
•
ICAO – Procedures for Air Navigation Services
– Rules of the Air and Air Traffic Services
(PANS-RAC, Doc 4444).
•
ICAO – Procedures for Air Navigation Services
– Aircraft Operations (PANS-OPS, Doc 8168),
Volume I, Flight Procedures (Post Amendment
No 11, applicable 1 November 2001).
•
FAR 91.119 for minimum safe altitude.
•
FAR 91.121 for altimeter setting.
•
FAR 91.129 for clarification of ATC communications.
•
FAR 91.221 and FAR 121.356 for TCAS
installation.
•
FAA Draft AC 91-XX – Altimeter Errors at Cold
Temperatures.
•
UK CAA CAP 413 for required criteria in
announcing leaving an altitude or FL.
Altitude Deviations
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Chapter 4
Descent and Approach Management
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Approach-and-Landing Briefing Note
4.1 - Descent and Approach Profile Management
Introduction
Descent Preparation:
Inadequate management of descent-and-approach
profile and/or incorrect management of aircraft
energy level during approach may in:
•
If a standard terminal arrival route (STAR) is
included in the FMS flight plan but is not
expected to be flown, because of anticipated
radar vectors, the STAR should be checked
(i.e., the track-distance, altitude restrictions
and/or
speed
restrictions)
against
the
anticipated routing to adjust the top-of-descent
point accordingly; and,
•
Wind forecast should be entered (as available)
on the appropriate FMS page, at waypoints
close to the top-of-descent point and along the
descent profile.
•
Loss of vertical situational awareness; and/or,
•
Rushed and unstabilized approaches.
Either situation increases the risk of approach-andlanding accidents, including those involving CFIT.
Statistical Data
Approximately 70 % of rushed and unstable
approaches involve an inadequate management of
the descent-and-approach profile and/or an
incorrect management of energy level; this includes:
•
•
Descent and Approach Briefing:
•
If a missed-approach is included in the FMS
flight plan, the missed approach should be
reviewed against the applicable approach chart.
Being higher or lower than the desired vertical
flight path; and/or,
Descent Initiation:
Being faster or slower than the desired speed.
•
If descent initiation is delayed by ATC, reduce
speed as appropriate to minimize the impact on
the descent profile.
Best Practices and Guidelines
Navigation Accuracy Check:
To prevent delay in initiating the descent and to
ensure an optimum management of descent-andapproach profile, descent preparation and
approach/go-around briefings should be completed
typically 10 minutes before the top-of-descent (or
when within VHF communication range).
•
If FMS navigation accuracy does not meet the
applicable criteria for terminal area navigation or
approach, no descent should be made below
the MEA or below the sector MSA without prior
confirmation of the aircraft position, using
navaids raw-data.
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A callout should be performed by the PNF if a flight
parameter exceeds the criteria for one of the
elements of a stabilized approach, as described in
Briefing Note 7.1 - Flying Stabilized Approaches.
Concept of next target and decision gates:
Throughout the entire flight a next target should be
defined, in order to stay ahead of the aircraft at all
times.
The next target should be any required combination
of one or more of the following elements:
Descent Profile Monitoring:
•
A position;
Descent profile should be monitored, using all
available instrument and chart references:
•
An altitude;
•
FMS vertical-deviation indication, as applicable;
•
A configuration;
•
Navaids and instruments raw-data; and,
•
A speed;
•
Charted descent-and-approach profile.
•
A vertical speed (as applicable); and,
•
A power setting.
Wind conditions and wind changes should be
monitored closely to anticipate any reduction in
head wind component or increase in tail wind
component, and to adjust the flight path profile in a
timely manner.
If it is anticipated that one or more element(s) of the
next target will not be met, the required corrective
action(s) should be taken without delay.
The descent profile may be monitored and adjusted
based on a typical 3000 ft per 10 nm descent
gradient (corrected for the prevailing head wind
component or tail wind component), while complying
with the required altitude and/or speed restrictions
(i.e., ensuring adequate deceleration management).
During the approach and landing, the successive
next targets should constitute gates that must be
met for the approach to be continued.
The final approach fix (FAF), the outer marker (OM)
or an equivalent fix (as applicable) should constitute
an assessment gate to confirm the readiness to
proceed further; this assessment should include the
following:
•
Visibility or RVR (and ceiling, as appropriate):
!
•
better than
minimums;
or
equal
to
Distance-to-go (nm) = FL / FPA (degrees)
applicable
Note :
In the above rule, the FL should be understood as
the FL difference (∆ FL) between the current
aircraft FL and the airfield FL.
Aircraft readiness:
!
•
The flight path vector, as available, can be used to
monitor the descent profile by checking that the
remaining track-distance to touchdown (in nm) is
approximately equal to the FL divided by the flightpath-angle (FPA, in degrees):
position, altitude, configuration and energy;
and,
Crew readiness:
!
briefing completed and
approach conditions.
agreement
Below 10 000 ft, flying at 250 kt IAS, the following
guidelines may be used to confirm the descent
profile and ensure a smooth transition between the
various phases of the approach:
on
The stabilization height should constitute a decision
gate; if the required configuration and speed are not
obtained or if the flight path is not stabilized when
reaching the stabilization height, an immediate goaround should be initiated.
•
9000 ft above airport elevation at 30 nm from
touchdown; and,
•
3000 ft above airport elevation at 15 nm from
touchdown (to account for deceleration and
slats/flaps extension).
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Descent Profile Adjustment/Recovery:
If flight path is significantly above the desired
descent profile (e.g. because of an ATC constraint
or a higher-than-anticipated tail wind), to recover the
desired flight path:
•
Revert from FMS vertical navigation to a
selected vertical mode, with an appropriate
speed target;
•
Maintain a high airspeed as long as practical;
•
Extend speed brakes (as allowed by SOPs
depending on airspeed and configuration,
keeping one hand on the speed brakes handle
until speed brakes are retracted); or,
•
•
Extend landing gear, if the use of speed brakes
is not sufficient; or,
!
CFIT; or,
!
overshoot of the localizer and/or of the
extended runway centerline.
•
Distraction leading to or resulting from a
two-heads-down situation;
•
Failure to resolve
disagreements;
•
Failure to effectively monitor the descent
progress using all available instrument
references (e.g., failure to monitor wind
conditions and/or wind changes); and/or,
•
Use of inappropriate technique to recover the
descent profile.
If the desired descent flight path cannot be
recovered, notify ATC for timely coordination.
Refer to Briefing Note 4.2 - Energy Management
during Approach for additional information.
The following factors and working errors often are
observed during transition and line training:
Late and therefore rushed descent and
approach preparation and briefing, resulting in
the omission of important items;
•
Failure to cross-check FMS data entries;
doubts
or
•
Timeliness
preparation;
•
Strict adherence to SOPs for FMS setup;
•
Cross-check of
crewmembers;
•
Use of PFD, ND and FMS CDU to support and
illustrate the descent, approach and go-around
briefings;
•
Confirmation of FMS navigation accuracy,
before deciding the use of automation (i.e., use
of FMS modes or selected modes) for the
descent and approach;
•
Review of terrain information
approach hazards; and,
•
Guidelines for descent planning, monitoring and
adjustment.
Adverse Factors and Typical Errors
•
ambiguities,
The following key points should be emphasized
during transition training and line training as well as
during line checks and line audits:
Maintain close reference to instruments
throughout the turn to monitor and control the
rate of descent, bank angle and position,
to prevent:
loss of control;
Failure to account for differences between
expected routing and actual routing (i.e., STAR
versus radar vectors);
Summary of Key Points
As a last resort, perform a 360-degree turn (as
practical and cleared by ATC).
!
•
Descent and Approach Profile Management
Page 3
of
descent
all
data
and
approach
entries
by both
and
other
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Associated Briefing Notes
The following Briefing Notes may be referred to for a
complete overview of the procedures, operational
recommendations and techniques involved in the
conduct of the descent and approach:
•
1.1 - Standard Operating Procedures,
•
1.3 - Operations Golden Rules,
•
4.2 - Energy Management during
Approach,
•
5.2 - Terrain Awareness,
•
6.1 - Being Prepared for Go-around,
•
7.1 - Flying Stabilized Approaches.
Regulatory References
•
ICAO – Annex 6 – Operation of Aircraft, Part I –
International Commercial Air Transport –
Aeroplanes, Appendix 2 – Contents of
Operations Manuals, 5.18, 5.19.
•
ICAO – Procedures for Air navigation Services –
Aircraft Operations (PANS-OPS, Doc 8168),
Volume I – Flight procedures.
•
FAA AC 120-71 – Standard Operating
Procedures for Flightdeck Crew Members.
•
JAR-OPS 1.1045 and associated Appendix A,
2.1 – Operations Manuals – structure and
contents.
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Approach-and-Landing Briefing Note
4.2 - Energy Management during Approach
Introduction
Statistical Data
Inability to assess or manage the aircraft energy level
during the approach often is cited as a causal factor
in unstabilized approaches.
Approximately 70 % of rushed and unstable
approaches involve an incorrect management of the
aircraft energy level, resulting in an excess or deficit
of energy, as follows:
Either a deficit of energy (being low and/or slow) or
an excess of energy (being high and/or fast) may
result in approach-and-landing accidents, such as:
•
Being slow and/or low on approach : 40 % of
events; or,
•
Being fast and/or high on approach: 30 % of
events.
•
Loss of control;
•
Landing short;
•
Hard landing;
•
Tail strike;
•
Runway excursion; and/or,
•
Airspeed and speed trend;
•
Runway overrun.
•
Altitude and vertical speed (or flight path angle);
•
Drag (i.e., drag caused by speed brakes,
slats/flaps and/or landing gear); and,
•
Thrust level.
Aircraft Energy Level
The level of energy of an aircraft is a function of the
following primary flight parameters and of their rate of
change (trend):
This Briefing Note provides background information
and operational guidelines for a better understanding:
•
Energy
management
approach:
−
•
during
intermediate
One of the tasks of the pilot is to control and monitor
the energy level of the aircraft (using all available
cues) in order to:
How fast can you fly down to the FAF or
outer marker ?
•
Energy management during final approach:
Maintain the aircraft at the appropriate energy
level for the flight phase and configuration:
−
−
Hazards associated with flying on the
backside of the power curve (as defined by
Figure 2).
•
Refer also to Briefing Note 7.2 – The Final
Approach Speed.
flight path, speed and thrust; or,
Recover the aircraft from a low energy or high
energy situation, i.e., from:
−
being too slow and/or too low; or,
−
being too fast and/or too high.
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Controlling the aircraft energy level implies balancing
the airspeed, thrust (and drag) and flight path, or
transiently trading one parameter for another.
The minimum stabilization height should be:
Autopilot and flight director modes, aircraft
instruments, warnings and protections are designed
to relieve or assist the flight crew in these tasks.
•
1000 ft above airfield elevation in IMC;
•
500 ft above airfield elevation in VMC.
Airlines usually require flight crews to cross the outer
marker (i.e., typically between 1500 ft and 2000 ft
above airfield elevation) with the aircraft configured in
the landing configuration.
Going Down and Slowing Down :
This allows time, before reaching the applicable
stabilization height, for:
How Fast Can you Fly Down to the Marker?
A study by the U.S. NTSB acknowledges that
maintaining a high airspeed down to the outer marker
(OM) does not favor the capture of the glideslope
beam by the autopilot or the aircraft stabilization at
the defined stabilization height.
•
Stabilizing the final approach speed; and,
•
Completing the landing checklist.
Aircraft deceleration characteristics:
Although
deceleration
characteristics
largely
depends on the aircraft type and gross-weight, the
following typical values can be considered for a quick
assessment and management of the aircraft
deceleration capability:
The study concludes that no speed restriction should
be imposed when within 3 nm to 4 nm before the
OM, mainly in instrument meteorological conditions
(IMC).
•
Nevertheless, ATC requests for maintaining a high
airspeed down to the marker (160 kt to 200 kt IAS
typically) are frequent at high-density airports, to
increase the landing rate.
−
−
•
Recall the definition of stabilization heights;
•
Illustrate the aircraft deceleration characteristics
in level flight and on a 3-degree glide path; and,
•
the distance from the OM to the runway
threshold; and,
−
the desired stabilization height.
10 to 15 kt-per-nm;
during extension of gear and landing flaps:
§
20 to 30 kt-per-nm;
Deceleration on a 3-degree glide path:
−
Provide guidelines for assessment of the
maximum speed which, reasonably, can be
maintained down to the marker, as a function of:
−
with approach flaps extended:
§
The purpose of the following part is to:
•
Deceleration in level flight:
with approach flaps and gear down, during
extension of landing flaps:
§
10 to 20 kt per nm.
Note:
A 3-degree glide path is typically equivalent to a
descent-gradient of 300 ft-per-nm or a 700 ft/mn
vertical speed, for a final approach ground speed
of 140 kt.
Decelerating on a 3-degree glide path in clean
configuration usually is not possible.
Stabilization height:
When capturing the glide slope with only slats
extended (i.e., with no flaps), typically 1000-ft
and 3 nm are flown while establishing the landing
configuration and stabilizing at the target final
approach speed.
The definition and criteria for a stabilized approach
are defined in Briefing Note 7.1 - Flying Stabilized
Approaches.
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Speedbrakes may be used to achieve a faster
deceleration, as allowed for the aircraft type.
MM
OM
Usually the use of speedbrakes is not recommended
or not permitted when below 1000 ft above airfield
elevation and/or in the landing flaps configuration.
Deceleration
Segment
( 10 kt/nm )
Typically, slats should be extended not later than
3 nm before the FAF.
2000 ft
1000 ft
500 ft
Figure 1 illustrates the aircraft deceleration
capability and the maximum possible speed at the
OM, based on a conservative deceleration rate of 10
kt per nm on a 3-degree glide path.
0
0
The following conditions are considered:
•
IMC (stabilization height 1000 ft above airfield
elevation); and,
•
Final approach speed ( V APP ) = 130 kt.
3.0
V APP
3 kt
= 130
6.0
V MAX
nm
6 = 160 kt
at OM
Figure 1
Deceleration along Glide Slope - Typical
Whenever being required to maintain a high speed
down to the marker, the above quick computation
may be considered for assessing the feasibility of the
ATC request.
The maximum deceleration achievable between the
OM (typically 6.0 nm from the runway threshold) and
the stabilization point ( 1000 ft above airfield elevation
/ 3.0 nm ) is:
Avoiding the Back Side of the Power Curve
10 kt-per-nm x ( 6.0 – 3. 0 ) nm = 30 kt
During an unstable approach, the airspeed or the
thrust setting often is observed to deviate from the
target values:
In order to be stabilized at 130 kt at 1000 above
airfield elevation, the maximum speed that can be
accepted and maintained down to the OM is
therefore:
•
Airspeed is below the target final approach speed
( V APP ); and/or,
•
Thrust is reduced and maintained at idle.
130 kt + 30 kt = 160 kt
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Thrust-required-to-fly curve:
The right side of the power curve is the normal zone
of operation.
Figure 2 illustrates the thrust-required-to-fly curve
(also referred to as the power curve).
The thrust balance is such that, at given thrust level,
any tendency to accelerate increases the thrustrequired-to-fly and, hence, brings back the aircraft to
the initial airspeed.
Thrust Required to Fly
3-degree glide slope - Landing configuration
160
150
Thrust required - in %
Conversely, any tendency to decelerate decreases
the thrust-required-to-fly and, hence, brings back the
aircraft to the initial airspeed
Given gross-weight
Given pressure altitude
Given fligh path
140
On the backside of the power curve, the thrust
balance is such that, at given thrust level, any
tendency to decelerate increases the thrust-requiredto-fly and, hence, amplifies the tendency to
decelerate.
130
120
Stable
Unstable
110
100
Thrust for V APP
90
90
100 110 120 130 140 150 160 170 180 190 200
V APP V minimum thrust
Conversely any tendency to accelerate decreases
the thrust-required-to-fly and, hence, amplifies the
tendency to accelerate.
Airspeed ( kt )
The minimum thrust speed ( V minimum thrust )
usually is equal to 1.35 to 1.4 V stall, in landing
configuration.
Figure 2
Power Curve - Typical
The minimum final approach speed is slightly in the
backside of the power curve.
The power curve features the following elements:
•
A point of minimum thrust-required-to-fly;
•
A part located right of this point;
•
A part located left of this point, called the
backside of the power curve.
If the airspeed is allowed to decrease below the final
approach speed, more thrust is required to maintain
the desired flight path and/or to regain the target
speed.
The difference between the available-thrust and the
thrust-required-to-fly (i.e., the thrust balance):
•
Represents the climb or acceleration capability
(if the available-thrust exceeds the requiredthrust); or,
•
Indicates that speed and/or flight path cannot be
maintained (if the required-thrust exceeds the
available-thrust).
In addition, if the thrust is set and maintained at idle,
no energy is immediately available to recover from a
low speed condition or to initiate a go-around (as
illustrated in Figure 3, Figure 4 and Figure 5).
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Engine acceleration characteristics:
When flying the final approach segment with the
thrust set and maintained at idle (approach idle), the
pilot should be aware of the acceleration
characteristics of jet engines, as illustrated below.
The aircraft certification (FAR – Part 25) ensures that
the thrust achieved after 8 seconds (starting from
flight/approach idle) allows a minimum climb gradient
of 3.2 % for go-around.
Thrust Response - Approach Idle to GA
( aicraft certification requirements )
Thrust Response from Idle to GA Thrust
( typical engine-to-engine scatter )
100
Thrust ( in % of GA thrust )
Thrust ( in % GA thrust )
100
80
60
40
20
Approach
idle
0
80
60
40
8 seconds (FAR 25)
20
0
0
1
2
3
4
5
6
7
8
9
10
0
1
Time ( seconds )
2
3
4
5
6
7
8
9
Time ( seconds )
Figure 3
Figure 4
Engine Response Scatter- Typical
Certified Thrust Response -Typical
The acceleration capability of a jet engine is
controlled to:
•
Protect the engine against a stall or flameout;
and,
•
Comply with the engine and aircraft certification
requirements ( U.S. FAR – Part 33 and FAR –
Part 25, respectively, or the applicable equivalent
regulation).
The engine certification (FAR – Part 33) ensures a
time of 5 seconds or less to accelerate from 15% to
95 % of the go-around thrust.
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Go-around from low speed/low thrust:
Table 1 indicates the thrust required (in % of the
TOGA thrust) during the transition from a stabilized
approach to a go-around.
Phase
Figure 5 illustrates the consequences associated
with flying an approach with:
% of TOGA Thrust
Stabilized approach
3-degree glide path / V APP
“Positive Climb”
Speed below the target final approach speed
( V APP ); and/or,
•
Thrust not stabilized or set and maintained at
idle.
In case of go-around, the initial altitude loss and the
time required for recovering the initial altitude are
increased if airspeed is lower than the final approach
speed and/or if thrust is not stabilized or set at idle.
20 %
Arresting altitude loss
•
30 %
Altitude Loss in Go-around
( Landing Configuration )
> 30 %
V APP / Stabilized thrust
30
Table 1 and Figure 5 illustrate the importance of
being stabilized on speed and on thrust when
initiating a go-around.
Altitude Loss
Thrust Required during GA Initiation
( in feet from go-around initiation )
20
Table 1
10
V APP /
Thrust decreasing
0
-10
-20
V APP –10 kt / Idle
-30
V APP / Idle
-40
-50
0
1
2
3
4
5
6
7
Time ( seconds )
Figure 5
Effect of Initial Speed and Thrust
on Altitude Loss during Go-around
(Typical)
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Summary of Key Points
A deceleration below the final approach speed should
be accepted only in the following cases:
•
GPWS terrain avoidance maneuver;
•
Collision avoidance maneuver; and,
•
Windshear procedure.
Nevertheless, in all three cases, the thrust levers
must be advanced to the maximum thrust
(i.e., go-around thrust) while initiating the maneuver.
Associated Briefing Notes
The following Briefing Notes should be reviewed along
with the above information for a complete overview of
the approach management:
•
6.1 - Being Prepared for Go-around,
•
7.1 - Flying Stabilized Approaches,
•
7.2 - Flying Constant-angle Non-precision
Approaches,
•
8.2 – The Final Approach Speed.
Regulatory References
•
ICAO – Annex 6 – Operation of Aircraft, Part I –
International Commercial Air Transport –
Aeroplanes, Appendix 2, 5.18, 5.19.
•
ICAO – Procedures for Air navigation Services –
Aircraft Operations (PANS -OPS, Doc 8168),
Volume I – Flight Procedures.
Other References
•
U.S. National Transportation Safety Board
(NTSB) – Report NTSB-AAS-76-5 –.Special
Study: Flight Crew Coordination Procedure in Air
Carrier Instrument Landing System Approach
Accidents.
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Chapter 5
Approach Hazards Awareness
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Approach-and-Landing Briefing Note
5.1 – Approach Hazards Awareness - General
Introduction
Factor
Factors that may contribute to approach-andlanding accidents include flight over hilly terrain,
reduced visibility, visual illusions, adverse winds,
contaminated runways and/or limited approach aids.
% of Events
Night time
75 %
IMC
59 %
Darkness or twilight
53 %
Non-precision approach or visual
approach
53 %
Precipitation ( rain or snow )
50 %
Absence of radar service
50 %
Over the past 40 years, approach-and-landing
accidents accounted for 55 % of total hull
losses.
Adverse wind (high crosswind,
tail wind or wind shear)
33 %
This statistic does not show a downward trend.
Absence of GPWS or radio
altimeter
29 %
Absence of letdown navaid,
approach/runway lighting or VASI
/ PAPI
21 %
Table 1, Table 2 and Table 3 illustrate the
respective contributions of the factors involved in:
Spatial disorientation or visual
illusions
21 %
•
All approach-and-landing accidents;
Runway contamination (standing
water, slush, snow or ice)
18 %
•
CFIT events; and,
•
Runway excursions and overruns.
Flight crews should be aware of the compounding
nature of these hazards during approach and
landing.
Statistical data
Approach-and-landing is the most hazardous phase
of any flight, as illustrated by the following data:
•
•
The flight segment from the outer marker to the
runway threshold averages only 4 % of flight
time, but accounts for 45 % of hull losses.
Table 1
All Approach-and-Landing Events
(Source: Flight Safety Foundation – ALAR Task Force)
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Flight Crew
Factor
% of Events
Low visibility
71 %
Hilly or mountainous terrain
67 %
•
Fatigue – reduced awareness:
−
Long duty time:
!
Long-haul operation; or,
!
Short-haul or medium-haul / multiplelegs operation;
Table 2
•
Unfamiliar airport; and/or,
CFIT Events
•
Unfamiliar instrument
procedure.
Factor
% of Events
Low visibility
73 %
Adverse wind conditions
67 %
or
visual
approach
Expected Approach
•
Step-down non-precision approach or circling
approach with no VASI / PAPI;
•
Visual approach in darkness; and/or,
•
Anticipated last-minute runway change.
Table 3
Runway Excursions and Overruns
Approach Charts
Awareness Program Outline
A company awareness program on approach-andlanding hazards should review and discuss the
following factors that may contribute to approachand-landing accidents.
•
Absence of a published STAR;
•
Missed-approach possible conflict with takeoff
on intersecting runways; and/or,
•
Incorrect or missing information.
When preparing and briefing an approach, these
factors may be either:
Airport Information Services
•
Inaccurate TAF information;
•
Known from the crew (by means of NOTAMs,
dispatcher’s briefing, ATIS, etc) and, thus, may
be briefed and accounted for; or,
•
Absence of current weather reports;
•
Absence of VOLMET;
Unknown and, thus, be discovered as the
approach-and-landing progresses
•
Absence of ATIS (or of English version of ATIS
message); and/or,
•
Inaccurate or outdated ATIS information
(absence of regular ATIS update, when
required).
•
Aircraft Equipment
•
Use (or absence) of the following safetyenhancing equipment:
−
GPWS;
Airport Air Traffic Control Services
−
TAWS;
•
−
TCAS;
Absence or primary
surveillance radar;
−
Wind shear warning and guidance; and/or,
•
Inadequate
practices;
−
Predictive windshear system.
Approach Hazards Awareness – General
Page 2
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and/or
ineffective
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•
Inadequate or non-standard air traffic control
procedures;
•
Inadequate air traffic flow management;
•
Mixing of IFR and VFR traffics;
•
Frequent uncontrolled VFR traffics in airport
vicinity;
•
Frequency congestion / controller overload
caused by high density traffic or by a single
controller operating tower and ground
frequencies;
•
Unsecured airport (i.e., absence of airport
perimeter fences, allowing vehicles, persons or
animals to access to runway or maneuvering
areas);
•
No illumination of wind sock or wind “T”;
and/or,
•
Faded painting of runway and/or taxiways
markings.
Terrain
•
Absence of adequate VHF coverage in known
FIR or TMA sectors;
•
Trees or man-made obstacles (antennas, ...)
penetrating the obstacle clearance level;
•
Inadequate coordination between international
and domestic FIRs;
•
Topographical features requiring unusual
procedures and reduced safety margins; and/or,
•
Absence of or failure to use landline
communications between two close airports;
and/or,
•
Terrain features resulting in GPWS activation
during approach.
•
Absence of English language proficiency in
ATC communications and/or use of nonstandard phraseology.
Refer to Briefing Note 5.2 – Terrain Awareness for
expanded information.
Visual Illusions
Airport Equipment
•
Airport environment (black hole, ...);
•
Absence of / limited / low intensity approach
and runway lighting (or part of it);
•
Runway environment; and/or,
•
•
Weather conditions.
Non-standard runway-edge lights spacing;
•
Absence of ILS;
•
ILS unusable beyond a specific point (because
of obstacles) or below a specific altitude
(because of approach over water);
Visibility
•
ILS without OM;
•
•
ILS without VASI/PAPI to support the visual
segment ;
•
Offset VOR/DME approach;
Wind conditions
•
VOR/DME with inoperative DME;
•
•
VOR incorrect calibration;
Shifting or gusty wind, crosswind or tail wind;
and/or,
•
NDB known as unreliable in adverse weather
conditions;
•
•
Known frequent wind shear on final approach of
specific runway under adverse weather and / or
wind conditions.
Non-precision or circling
absence of VASI / PAPI;
•
VASI/PAPI being incorrectly calibrated or
inoperative;
approach
Refer to Briefing Note 5.3 – Visual Illusions
Awareness for expanded information.
with
Darkness, low visibility (rain, fog, mist, haze,
low lighting, smoke).
to Briefing Note 5.4 – Wind Shear
Awareness for expanded information.
Refer
Approach Hazards Awareness – General
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Runway condition
Decision-making and Countermeasures
•
Wet, but known as slippery-when-wet;
•
Contaminated with standing water, slush, snow
or ice;
•
Heavy rubber deposit in touchdown zone;
•
Reduced braking action;
•
Insufficient water drainage or runway surface
condition leaving water puddles after rain;
and/or,
•
A company awareness program on approach-andlanding hazards should stress the following
elements of effective crew coordination and
decision-making:
•
Comply with standard operating procedures
(SOPs),
published
limitations,
specific
operational recommendations and flying
techniques;
•
Adjust and use the approach and go-around
briefings to heighten the flight crew awareness
of the specific hazards of the approach; and,
•
Anticipate and be prepared for the worst case
(i.e., “expecting the unexpected” by adopting a
“What if ?” attitude);
Undulated surface in touchdown zone area.
Taxiways
•
Absence of high-speed-exit taxiways;
•
Absence of parallel taxiway, thus requiring back
track on the active runway; and/or,
−
Request a precision approach into the wind,
whenever available;
Non-standard taxiway marking and/or nonstandard signs.
−
Define next targets and an approach gate
that must be met for the approach to be
continued;
−
Wait for better conditions (fuel permitting);
or,
−
Divert to an airport with better weather
conditions, wind conditions and/or runway
conditions.
•
Prepare options to counter approach-andlanding hazards, for example:
Low temperature operation
•
Absence of a defined OAT threshold below
which, a temperature correction on published
altitudes is required.
Bird Strike Hazard
•
Permanent or seasonal bird activity, without
available bird control program and squad.
Approach Hazards Awareness – General
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Associated Briefing Notes
Dedicated Briefing Notes provide specific and
expanded information on the following approach
hazards:
•
5.2 - Terrain Awareness,
•
5.3 - Visual Illusions Awareness,
•
5.4 - Windshear Awareness,
•
6.1 - Being Prepared to Go-around,
•
6.3 - Terrain Avoidance (Pullup) Maneuver.
Associated Documents
The following documents published by the Flight
Safety Foundation should be considered also when
developing a company awareness program on
approach-and-landing hazards:
•
Approach and Landing
Tool/Checklist; and,
•
Approach and
Planning Guide.
Landing
Risk
Awareness
Risk
Reduction
Approach Hazards Awareness – General
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Approach-and-Landing Briefing Note
5.2 – Terrain Awareness – When and How ?
Introduction
Factor
Terrain awareness is defined as the combined
awareness and knowledge of:
•
Aircraft position;
•
Aircraft altitude;
•
Applicable minimum safe altitude (MSA);
•
Terrain location and features; and,
•
Other hazards.
This Briefing Note provides a set of operational
recommendations and training guidelines to
establish and maintain the desired level of terrain
awareness.
71 %
Hilly or mountainous terrain
67 %
Non-precision approach
57 %
Areas of flat terrain
29 %
Table 1
Terrain Factors in CFIT Events
CFIT events during initial / intermediate approach or
during final approach usually result from a
premature descent below the initial-approach
minimum-safe-altitude or below the minimumdescent-altitude (MDA).
Statistical data
CFIT events account for approximately 45 %
of approach-and-landing accidents but are the
leading cause of fatalities.
The absence of acquisition or the loss of visual
references is the most common causal factor in
CFIT accidents occurring during approach-andlanding; this includes:
•
Low visibility
( often on runway extendedcenterline and within 15 nm of
runway threshold )
When and how to build and maintain terrain
awareness ?
•
% of Events
Navigation and Altitude Deviations
When referring to terrain awareness, the following
definitions need to be kept in mind.
Descending below the MDA(H) or DA(H) without
adequate visual references or with incorrect
visual references (e.g., a lighted area in the
airport vicinity, a taxiway or an other runway); or,
Navigation (course) deviation:
•
Continuing the approach after the loss of visual
references (e.g., visual references lost because
of a fast moving rainshower or fog patch).
Operation of an aircraft beyond the course
clearance issued by ATC or beyond the defined
airway system.
Altitude deviation:
•
Deviation from the assigned altitude (or flight
level) equal to or greater than 300 ft.
Terrain Awareness – When and How ?
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•
Inadequate terrain separation:
•
Any operation with a terrain separation of less
than 2000 ft in designated mountainous areas or
less than 1000 ft in all other areas (except
otherwise authorized and properly assigned by
ATC in terminal areas).
The first golden rule states Fly, Navigate,
Communicate and Manage, in that order.
Navigate can be defined by the following three
“know where …” statements:
Navigation ( course ) deviations and altitude
deviations usually are caused by monitoring errors
and may result in inadequate terrain separation.
Monitoring errors involve the crew inability to
monitor the aircraft trajectory and instruments while
performing autopilot or FMS entries, or while being
interrupted or distracted.
1000 ft, in case of altitude deviation; and,
•
10 nautical miles, in case of course deviation.
−
Know where you are;
−
Know where you should be; and,
−
Know where the terrain and obstacles are.
•
Approach and go-around briefings;
•
Altimeter setting and cross-check procedures:
Delayed recognition of monitoring errors is
estimated to result in the following mean deviations
from the intended vertical or lateral flight path:
•
Operations Golden Rules ( refer to Briefing Note
1.3 – Operations Golden Rules ):
−
When receiving an altitude clearance,
immediately set the cleared altitude in the
FCU altitude window (even before
readback, if appropriate because of
workload);
−
Ensure that selected altitude is crosschecked by both crewmembers;
−
Ensure that the cleared altitude is above the
applicable minimum safe altitude; and,
−
Positively confirm any altitude clearance
below the MSA, when under radar vectoring
(or be aware of applicable minimum
vectoring altitude for the sector).
Terrain Awareness - When and How ?
This paragraph provides an overview of:
•
Opportunities available to enhance terrain
awareness (e.g., operations manuals, technical
training, navigation charts); and,
•
Operational recommendations and techniques
proposed to establish and maintain the desired
level of terrain awareness.
•
Descent profile management;
•
Energy management;
•
Terrain awareness;
Standard Operating Procedures
•
Approach hazards awareness;
Standard operating procedures (SOPs) should
emphasize the following terrain-awareness-items:
•
Elements of a stabilized approach and approach
gates;
•
Readiness and commitment to respond to a
GPWS / TAWS alert; and,
This overview identifies the most important terrainawareness-items (i.e., CFIT-critical item).
•
Task sharing and standard calls for effective
cross check and backup, particularly for mode
selections and target entries;
Terrain Awareness – When and How ?
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Use of radio altimeter:
Note 2 :
The setting of the baro-altimeter bug and radioaltimeter DH should be in line with the
applicable SOPs.
CAT II DA or CAT I DA can be set in readiness
for a reversion to CAT I minima.
Radio altimeter callouts can be either:
The following typical summary is based on the
use of QNH for altimeter setting.
Visual
Baro Bug
RA DH
MDA/DA of
instrument
approach
or
200 ft
MDA
DA
ILS CAT I RA
DA
ILS CAT II
Note 2
ILS CAT III
DA
with DH
Note 2
ILS CAT III
TDZ altitude
automatically generated by a synthesized
voice.
200 ft
To enhance the flight crew’s terrain awareness,
a callout Radio Altimeter Alive, should be
announced by the first crewmember observing
the
radio
altimeter
activation
at
2500 ft AGL.
200 ft
The RA reading should be included in the
instrument scan for the remainder of the
approach.
Note 1
No RA
−
Callouts should be tailored to the airline
operating policy and to the type of approach.
Note 1
ILS CAT I
called (verbalized) by the PNF or the flight
engineer; or,
Note 1
200 ft AAL
Non-ILS
−
RA DH
Training
Altitude Awareness Program:
RA DH
The implementation of an altitude awareness
program by several airlines has reduced significantly
the number of altitude deviations.
An altitude awareness program can be developed
based on the contents of the Briefing Notes
no DH
3.1 Altimeter Setting – Use of Radio Altimeter
and 3.2 – Altitude Deviations.
Table 1
The altitude awareness program should emphasize
the following aspects:
Setting of Baro Altimeter Bug and Radio Altimeter DH
Note 1 :
•
The RA DH can be set (e.g., at 200 ft), for
terrain awareness purposes. In this case, the
use of the radio altimeter should be discussed
during the approach briefing.
For all approaches, except CAT I with RA,
CAT II and CAT III ILS approaches,
the approach MINIMUM callout will be based on
the baro-altimeter bug set at the MDA(H) or
the DA(H).
•
Awareness of altimeter setting errors, e.g.:
−
29.XX in.hg versus 28.XX or 30.XX in.hg;
or,
−
29.XX in.hg versus 9XX hPa.
Awareness of altitude corrections for low OAT
operations and awareness of pilot’s and/or
controller’s responsibility in applying these
corrections.
Terrain Awareness – When and How ?
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•
Pilot / Controller Communications:
A company awareness and training program on pilot
/ controller communications should be developed
and implemented, involving pilots and ATC
personnel ( refer to Briefing Note 3.1 – Effective
Pilot / Controller Communications ).
Terrain avoidance (pull-up) maneuver ( see
Briefing Note 6.3 – Response to GPWS – Pull-up
Maneuver ).
Flight Overview
Cockpit Preparation – Departure Briefing
Route Familiarization Program:
The computerized flight plan should be crosschecked against the ATC clearance and the FMS
flight plan, using the SID and enroute charts, the
FMS CDU and the ND to support and illustrate this
cross-check.
A training program should be implemented for
departure,
route,
approach
and
airport
familiarization, using:
•
High-resolution paper material;
•
Video program; and/or
•
Simulator with enhanced visual capability.
The takeoff and departure briefing should include
the following terrain-awareness-items, using all
available charts and flight deck displays to support
and illustrate the briefing:
Whenever warranted, new pilots should conduct a
route familiarization check:
•
Significant terrain or obstacles
intended departure course; and,
•
As flight crewmember with a check airman; or,
•
SID routing and minimum safe altitudes.
•
As observer with a qualified flightcrew.
along the
Standard Instrument Departure - SID
CFIT Training program:
When flying a published SID, flight crew should:
The CFIT training module should include the
following academic and maneuvering aspects:
•
Be aware of whether or not the departure is
radar-monitored by ATC;
•
•
Maintain a sterile cockpit until reaching 10 000 ft
or the sector minimum safe altitude, particularly
at night or in IMC;
•
Monitor the correct sequencing of the flight plan
at each waypoint and the correct guidance after
sequencing the waypoint, particularly after a
flight plan revision or after performing a DIR TO:
Understanding each GPWS mode, this should
include:
−
Associated operational scenario(s);
−
Protection envelope:
−
!
aircraft configuration (i.e., landing gear,
flaps);
!
barometric altitude range or radioaltitude range; and/or
−
Ensure that the direction of turn and the TO
waypoint are in accordance with the SID.
!
airspeed range;
−
In case of incorrect flight plan sequencing
and/or of incorrect lateral guidance, crew
should be alert to perform a DIR TO [an
appropriate waypoint] or to revert to
selected lateral navigation.
Alert or warning activation:
!
barometric-altitude loss;
!
vertical speed;
!
radio-altimeter closure rate;
!
radio altitude; or
!
glide slope deviation;
Enroute Navigation
The enroute charts should be readily accessible,
in readiness for a possible loss of FMS navigation or
if any doubt exists about the FMS lateral guidance.
Terrain Awareness – When and How ?
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Flight Progress Monitoring
ATIS:
During climb, cruise and descent, flight crew should:
Review and discuss the following items:
•
Monitor FMS guidance and navigation accuracy;
•
Runway in use (type of approach);
•
Monitor instruments and navaids raw data (as
applicable);
•
Expected arrival route ( STAR - or radar
vectors);
•
Altimeter setting (QNH or QFE, as required);
and,
•
Transition level (unless standard for the country
or for the airport).
•
Use all available information (i.e., cockpit
displays, navaids raw data and charts); and,
•
Request confirmation or clarification from ATC if
any doubt exists about terrain clearance,
particularly when being radar vectored.
Descent Preparation – Approach and Goaround Briefing
Approach Chart:
A thorough
regardless of:
Review and discuss the following terrainawareness-items using the approach chart and the
FMS/ND (as applicable):
briefing
should
be
performed
•
How familiar the destination airport and the
approach may be; or,
•
How often
together.
the
crewmembers
have
flown
The briefing should help the PF (giving the briefing)
and the PNF (receiving and acknowledging the
briefing) to reach and share a common mental
model of the approach.
In hilly or mountainous areas, the briefing should
include the following terrain-awareness-items:
•
Descent profile and descent management;
•
Terrain features;
•
Energy management (i.e., deceleration and
configuration management); and,
•
Other approach hazards (e.g., black hole).
The flight management system (FMS) operational
pages and the ND should be used to guide and
illustrate the briefing, and to confirm the various
data entries.
An expanded review of the terrain-awareness-items
to be included in the approach briefing – as practical
and appropriate for the conditions of the flight – is
provided hereafter.
•
Designated runway and approach type;
•
Chart index number and date;
•
Minimum Safety Altitude (MSA) - reference
point, sectors and altitudes;
•
Let-down navaid frequency and identification
(confirm the correct navaid setup);
•
Airport elevation;
•
Approach transitions (fixes, holding pattern,
altitude and speed constraints/restrictions,
required navaids setup);
•
Initial approach fix (IAF) and intermediate
approach fix (IF), as applicable (positions and
crossing altitudes);
•
Final approach course (and lead-in radial);
•
Terrain features (location and elevation of
hazardous terrain or man-made obstacles);
•
Approach profile view :
-
Final approach fix (FAF);
-
Final descent point (if different from FAF);
-
Visual descent/decision point (VDP);
-
Missed-approach point (MAP);
-
Typical vertical speed at expected final
approach ground speed (GS); and,
-
Touchdown zone elevation (TDZE).
Terrain Awareness – When and How ?
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In low temperature, the true altitude is lower than
the indicated altitude, resulting in a lower-thananticipated terrain separation and in a possible
terrain clearance hazard (as illustrated by Figure 1,
for a – 40 degree Celsius OAT).
Missed approach :
-
Lateral and vertical navigation; and,
-
Significant terrain or obstacles.
Low OAT Operation
True
Altitude
When operating with a low OAT, temperature
corrections on the indicated altitude need to be
applied to all the following published altitudes:
•
MEA, MSA;
•
Transition routes altitude;
•
Procedure turn altitude (as applicable);
•
FAF altitude;
•
Step-down altitude(s) and MDA(H) during a nonILS approach;
•
•
Given Atmospheric Pressure
( pressure altitude )
Indicated
Altitude
3000 ft
2000 ft
1600 ft
2000 ft
1000 ft
High OAT
OM crossing altitude during an ILS approach;
and,
Standard OAT
Low OAT
Figure 1
Effect of OAT on True Altitude
Waypoints crossing altitudes, during a GPS
approach flown with barometric vertical
navigation.
Flying into low temperature has the same effect as
flying into a low-pressure area; the aircraft is lower
than the altimeter indicates.
In a standard atmosphere, the indicated altitude
reflects the true altitude above the mean sea level
(MSL) and therefore provides a reliable indication of
terrain separation.
These effects are summarized and illustrated in
Table 2, featuring a well-known aviation golden rule:
When OAT is significantly warmer or colder than the
standard temperature, the indicated altitude is
higher or lower than the true altitude (as illustrated
by Figure 1.
From
To
Atmospheric
Pressure
High
Low
OAT
Warm
Cold
Look
out
below
Table 2
Atmospheric Pressure and Temperature Effects
on True Altitude
Terrain Awareness – When and How ?
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Airport charts:
Review and discuss the following
awareness-items using the airport charts:
Monitor the correct sequencing of the flight plan at
each waypoint and the correct guidance after
sequencing the waypoint, particularly after a flight
plan revision or after performing a DIR TO:
terrain-
•
Approach and runway lighting, and other
expected visual references; and,
•
Ensure that the direction-of-turn and the TO
waypoint are in accordance with the SID.
•
Specific hazards (such as man-made obstacles,
as applicable).
•
In case of incorrect flight plan sequencing
and/or of incorrect lateral guidance, crew should
be alert to perform a DIR TO [an appropriate
waypoint] or to revert to selected lateral
navigation.
If another airport is located in the close vicinity of the
destination airport, relevant details or procedures
should be discussed for awareness purposes.
Changes in clearances should be fully understood
before being accepted and implemented.
Use of automation:
For example, being cleared to a lower altitude
should never be understood as a clearance to
descend (prematurely) below the charted sector or
segment minimum safe altitude.
Discuss the intended use of automation for vertical
and lateral navigation:
•
•
Use of FMS-managed guidance or selected
modes; and,
When being radar vectored, make sure that :
Use of precision approach, constant-angle or
step-down non-precision approach, as required.
•
The controller has clearly identified your radar
return by stating “radar contact”;
•
The controller can read obstacle clearance
altitudes on his or her radar scope (awareness
of minimum vectoring altitude and responsibility
for terrain separation);
•
The controller does not forget that you are on a
radar vector, heading toward high or rising
terrain;
If the accuracy criteria for lateral FMS navigation in
terminal area and/or for approach are not met,
revert to a selected lateral mode with ND in ROSE
or ARC mode.
•
The pilot / controller two-way communication
remain effective at all times;
•
You maintain your own vertical and horizontal
situational awareness; and,
If flying with IRS ONLY navigation, do not descend
below the sector MSA without positive confirmation
of the aircraft position, using navaids raw data.
•
You request confirmation or clarification from
ATC without delay and in clear terms, in case of
any doubt.
Descent Management and Monitoring
Before entering the terminal area (TMA), check the
FMS navigation accuracy (using navaids raw data)
against the applicable criteria for terminal or
approach navigation.
Be aware of whether or not the arrival is radarmonitored by the ATC.
To prevent an excessive terrain-closure-rate,
consider a maximum vertical speed and reduce this
maximum limit with decreasing altitude (e.g., do not
exceed – 2000 ft/mn when below 2000 ft AGL and
– 1000 ft/mn when below 1000 ft AGL).
Maintaining a sterile cockpit when below 10 000 ft or
below the sector minimum safe altitude (MSA),
particularly at night or in instrument meteorological
conditions (IMC).
During the final approach segment, the primary
attention of PF and PNF pilots should be directed to
any required altitude constraint or altitude / distance
check prior to reaching the MDA(H) or DA(H).
Standard Arrival - STAR
Terrain Awareness – When and How ?
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−
Radio altimeter readings below obstacle clearance
levels, listed below, should prompt an immediate
altitude and position check:
•
Initial approach (from IAF to IF) : 1000 ft AGL;
•
Intermediate approach (from IF to FAF, or at
minimum radar vectoring altitude) : 500 ft AGL;
•
Final approach (non-precision
inbound of FAF) : 250 ft AGL.
•
Airport environment:
−
•
approaches,
Unless the airport features high close-in terrain,
the RA reading (height AGL) should reasonably
agree with the height above airfield elevation
(obtained by direct reading of the altimeter if using
QFE, or by computation if using QNH).
•
lack of GPWS or TAWS.
Night “black hole” and/or rising(sloping)
terrain along the approach path;
Airport equipment:
−
Lack of or restricted radar coverage;
−
Lack of precision approach and/or lack of
VASI/PAPI; and,
−
Limited and/or low-intensity approach and
runway lighting.
Navigation charts:
Preparedness to Go-around
−
Lack of published
approach procedures;
In IMC or at night, immediately respond to any
GPWS / TAWS warning.
−
Lack of published information on minimum
radar vectoring altitudes; and,
Be prepared and minded to go-around if the
conditions for a safe approach and landing are not
met (e.g., unstabilized approach at or below the
approach gate / stabilization height).
−
Absence on colored terrain contours on
approach charts.
•
departure
and/or
Training :
Circling Approaches
−
Absence
of
area
and/or
familiarization training; and,
When performing a circling approach, be aware of
and stay within the applicable obstacle clearance
protected area.
−
Inadequate
knowledge of
applicable
obstacle clearance and/or sector minimum
vectoring altitude.
•
Factors Affecting Terrain Awareness
The following factors often are cited as affecting the
horizontal or lateral situational awareness and
therefore the terrain awareness.
These factors should be addressed by developing
company prevention strategies and lines-ofdefense, initiating appropriate actions with state
agencies, operational authorities and service
providers:
•
Aircraft equipment:
−
Lack of navigation display with terrain
display or radar display with mapping
function;
−
lack of area navigation (RNAV) capability;
Standard operating procedures:
−
Inadequate briefings;
−
Monitoring errors (i.e., inability to monitor
the aircraft trajectory and instruments while
performing FMS entries or while being
interrupted or distracted);
−
Inadequate monitoring of flight progress
(i.e., being behind the aircraft);
−
Incorrect use
automation;
−
Omission of a normal checklist or part of a
normal checklist (usually because of
interruption or distraction); and/or,
−
Deliberate or inadvertent non-adherence to
procedures.
Terrain Awareness – When and How ?
Page 8
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of
or
interaction
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•
To reduce altimeter-setting errors, flight crew
should:
Pilot/Controller Communications:
−
−
−
•
Getting to Grips with
Approach-and-Landing Accidents Reduction
Omission of position report at first radio
contact in an area without radar coverage
(i.e., reducing the controller’s situational
awareness);
Breakdown in pilot / controller or intra-crew
communications (e.g., readback/hearback
errors, failure to resolve doubts or
ambiguities,
use
of
non-standard
phraseology); and/or,
Accepting an amended clearance without
prior evaluation.
Human Factors and CRM:
−
Incorrect CRM practices (absence of
crosscheck and back-up for AP mode
selections and AP/FMS data entries, late
recognition of monitoring errors);
•
Be aware of altimeter setting changes due to
prevailing weather conditions (e.g., extreme cold
or warm fronts, steep frontal surfaces, semipermanent or seasonal low pressure areas);
•
Be aware of the altimeter setting unit in use at
the destination airport;
•
Be aware of the anticipated altimeter setting,
using two independent sources for cross-check
(e.g., METAR and ATIS messages);
•
Ensure effective cross-check and back-up;
•
Adhere to SOPs for:
− reset of altimeters in climb and descent (per
FCOM or per company’ SOPs);
−
Inadequate decision-making;
−
Failure to resolve a doubt or confusion;
− use of standby altimeter to cross-check main
altimeters;
−
Fatigue;
− altitude callouts;
−
Complacency;
− RA callouts; and,
−
Spatial disorientation; and/or,
− setting of baro-altimeter bug and RA DH.
−
Visual illusions.
•
Summary of key points
The following key points and recommendations
should be used in the development of company
prevention strategies and actions enhancing terrain
awareness.
Cross-check that the cleared / assigned altitude
is above the sector minimum safe altitude
(unless crew is aware of applicable minimum
vectoring altitude for the sector).
Flight progress monitoring
Flight monitoring for terrain awareness includes:
Approach Charts
•
Monitoring FMS guidance and FMS navigation
accuracy;
Providing flight crews with departure and approach
charts featuring terrain with color shaded contours.
•
Monitoring instruments and navaids raw data;
•
Using all available information available (i.e.,
cockpit displays, navaids raw data and charts);
and,
•
Requesting confirmation or clarification from
ATC if any doubt exists about terrain clearance,
particularly when being radar vectored.
Altimeter setting
Promoting strict adherence to adequate SOPs to
reduce altimeter-setting errors and for optimum use
of baro-altimeter bug and radio-altimeter DH.
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The role and tasks of the PNF should be
emphasized by highlighting is role as pilot
monitoring.
Approach and go-around briefing
The following terrain awareness critical items should
be included in the approach and go-around briefing:
•
Minimum safety altitudes;
•
Terrain and man-made obstacles features;
•
Applicable approach minimums (visibility or
RVR, ceiling as applicable);
•
Applicable stabilization height (approach gate);
•
Final approach descent flight path angle (and
vertical speed); and,
•
Awareness of other approach hazards
Pilots should receive education and training on
visual illusions and spatial disorientation.
Associated Briefing Notes
The following Briefing Notes provide expanded
information on subjects and matters related to
terrain awareness:
Go-around altitude and missed-approach initial
steps.
•
1.1 - Standard Operating Procedures.
Preparedness and commitment for go-around
•
1.2 – Optimum Use of Automation.
The following should be stressed:
•
1.3 - Operations Golden Rules.
•
•
1.4 – Standard Calls.
•
1.5 – Use of Normal Checklists.
•
1.6 – Approach and Go-around Briefing.
•
2.3 – Effective Crew / ATC
Communications.
•
2.4 – Intra-Cockpit Communications –
Managing interruptions and
Distractions.
•
3.2 – Altitude deviations.
•
6.1 – Being Prepared for Go-around.
•
6.3 – Terrain-Avoidance ( GPWS Pullup )
Maneuver
•
Being committed for an immediate response to
any GPWS / TAWS warning (particularly at
night or in IMC); and,
Being prepared and minded to go-around.
Pilot / controller communications
An awareness and training program to improve pilot
/ controller communications should be developed
based on the contents of Briefing Note
2.3 – Effective Pilot/Controller Communications.
Crew coordination, cross-check and back-up
The following terrain-awareness elements of an
effective cross-check and back-up should be
emphasized:
•
Regulatory References
Assertive challenging by PNF (i.e., maintaining
situational awareness and voicing any concern
about the safe progress of the flight);
•
Standard calls ( particularly, altitude calls);
•
Excessive-parameter-deviation callouts; and,
•
Task sharing and standard calls for the
acquisition of visual references.
The following regulatory references are provided to
assist the reader in a quick and easy reference to
the related regulatory material:
•
ICAO - PANS-OPS - Volume I - Part VI –
Altimeter setting procedures - Chapter 3 – Low
OAT operation - Altitude corrections.
•
FAR 91.3 – Responsibility and authority of the
pilot in command.
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•
FAR 91.119 – Minimum safe altitudes: General.
Other References
•
FAR 91.121 – Altimeter settings.
•
FAR 91.123 – Compliance with ATC clearances
and instructions.
The following Flight Safety Foundation references
can be used to further illustrate and complement the
information contained in this Briefing Note:
•
CFIT Education and Training Aid.
•
FAR 91.155 – Basic VFR weather minimums.
•
CFIT Checklist – Evaluate the Risk and Take
Action.
•
FAR 91.157 – Special VFR weather minimums.
•
ALAR Risk Awareness Tool/Checklist.
•
FAR 91.175 – Takeoff and landing under IFR.
•
ALAR Risk Reduction Planning Guide.
•
FAR 91.185 – IFR operations:
Two-way communications failure.
•
Flight Safety Digest – Killers in Aviation –
Nov.98-Feb.99.
•
FAR 97 – Standard Instrument Approach
Procedures – Terminal Instrument Approach
Procedures (TERPS).
•
FAR 121.97 or 121.117 – Airports: Required
data.
•
FAR 121.135 – Manual Requirements –
Operations Manual – Contents.
•
FAR 121.315 – Cockpit check procedure.
•
FAR 121.360 – Ground proximity warning –
glide slope deviation alerting system.
•
FAR 121.443 and 121.445 – Route, Special
areas and airports qualification for pilot in
command (PIC).
•
Photo credit : TAKEOFF The Swiss Professional Pilots’ Association Magazine
FAR 121.542 – Flight crewmember duties
(sterile cockpit rule).
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Approach-and-Landing Briefing Note
5.3 - Visual Illusions Awareness
Introduction
Visual illusions take place when conditions modify
the flight crew perception of the environment relative
to his / her expectations.
Factor
Visual illusions may result in landing short of the
runway, hard landing or runway overrun, but also
cause spatial disorientation and loss of control.
This Briefing Note provides an overview of:
•
Factors and conditions that may cause visual
illusions;
•
How visual illusions affect the pilot’s perception
of the airport / runway environment and runway;
and,
•
How to lessen the effects of visual illusions by
implementing related prevention strategies and
lines-of-defense in training and line operation.
% of Events
Night time
75 %
Low visibility
70 %
IMC
59 %
Darkness or twilight
53 %
Non-ILS approach
53 %
Precipitation ( rain or snow )
50 %
Visual approach
30 %
Statistical Data
Visual
illusions
disorientation
Visual approaches are a causal factor in 30 % of all
approach-and-landing accidents and in 40 % of fatal
accidents.
Absence of :
or
spatial
21 %
21 %
- letdown navaid
- approach/runway lighting
Visual approaches at night present a greater
exposure because of reduced visual cues,
increased likelihood of visual illusions and risk of
spatial disorientation.
- VASI / PAPI
Low visibility and/or precipitations are a
circumstantial factor in more than 70 % of
approach-and-landing accidents, including those
involving CFIT.
Table 1
Visual Factors in Approach-and-Landing Events
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Visual illusions affect perception
distances and/or intercept angles.
Visual Illusions – Factors and Conditions
The following factors and conditions affect the flight
crew ability to accurately perceive the environment,
resulting in visual illusions.
Ground texture and features;
•
Off-airport light patterns such as brightly lighted
parking lots or streets;
•
“Black hole” along the final approach flight path;
and/or,
•
Uphill or downhill sloping terrain before the
runway threshold or in the approach path
environment.
heights,
Visual illusions are most critical when transitioning
from IMC and instrument references to VMC and
visual references.
Airport environment:
•
of
Visual illusions (such as the black-hole effect) affect
the flight crew vertical and horizontal situational
awareness, particularly during the base leg and
when turning final (as applicable) and during the
final approach.
Visual illusions usually induce crew inputs
(corrections) that cause the aircraft to deviate from
the original and intended vertical or lateral flight
path.
Visual illusions can affect the decision about when
and how fast to descend from the MDA(H).
Runway environment:
•
Runway dimensions (aspect ratio);
•
Runway uphill or downhill slope;
•
Terrain drop-off at the approach end of the
runway;
•
Approach and runway lighting; and/or,
•
Runway condition (e.g., wet runway).
The following paragraph provides an expanded
overview of all the factors and conditions creating
visual illusions to discuss how each factor or
condition may affect the pilot perception of:
Weather conditions:
•
Ceiling;
•
Visibility (i.e., vertical visibility, slant visibility and
horizontal visibility); and/or,
•
Cloudiness (e.g., rain, fog or fog patches, haze,
mist, smoke, snow, whiteout effect).
•
The airport and runway environment;
•
The terrain separation; and,
•
The aircraft vertical or lateral deviation from the
intended flight-path.
Usually, more than one factor is involved in a given
approach, compounding the individual effects.
Airport environment:
•
How do Visual Illusions Affect the Pilot’s
Perception ?
“Black hole” along the final approach flight path:
−
Visual illusions result from the absence of or the
alteration of visual references that modifies the pilot
perception of his / her position relative to the runway
threshold.
Visual Illusions Awareness
Page 2
In case of approach over water or with an
unlighted area on the approach path, the
absence of visible ground features reduces
the crew ability to perceive the aircraft
lateral position and vertical position relative
to the intended flight path.
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Runway environment:
Uphill or downhill terrain before the runway
threshold:
−
•
An uphill slope in the approach zone or a
drop-off of terrain at the approach end of
the runway creates an illusion of being too
high (i.e., impression of a steep glide path,
as shown on Figure 1), thus:
!
!
Runway dimensions / aspect ratio (Figure 3):
−
the runway aspect ratio (i.e., its length
relative to its width) affects the crew visual
perspective view of the runway:
possibly
inducing
a
correction
(increasing the rate of descent) that
places the aircraft below the intended
glide path; or,
!
a large or short runway (low aspect
ratio) creates an impression of being
too low; and,
!
a narrow or long runway (high aspect
ratio) creates an impression of being
too high.
preventing the flight crew from detecting
a too shallow flight path.
Perceived Glide Path
Actual Glide Path
Figure 3
Figure 1
−
Photo - LFBO 15 R ( 3500 m x 45 m )
3-degree glide slope / 200 ft RA
A downhill slope in the approach zone
creates an illusion of being too low (i.e.,
impression of a shallow glide path, as
shown on Figure 2), thus:
•
Runway uphill or downhill slope:
!
possibly inducing a correction placing
the aircraft above the intended glide
path; or,
−
!
An uphill slope creates an illusion of being
too high (impression of a steep glide path);
and,
preventing the flight crew from detecting
a too steep flight path.
−
A downhill slope creates an illusion of being
too low (impression of a shallow glide path).
•
Approach and runway lighting:
−
Perceived Glide Path
Actual Glide Path
Figure 2
Visual Illusions Awareness
Page 3
The approach and runway lighting (including
the touchdown zone lighting ) affects
the dept perception as a function of:
!
The lighting intensity;
!
The daytime or night time conditions;
and,
!
The weather conditions.
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−
Bright runway-lights create the impression
of being closer to the runway (hence on a
steeper glide path);
−
Low intensity lights create the impression of
being farther away (hence on a shallower
glide path);
−
−
−
A non-standard spacing of runway lights
also modifies the pilot’s perception of the
runway distance and glide path; and,
If runway lighting is partially visible (e.g.,
during the downwind leg or during the base
leg of a visual or circling approach), the
runway may appear being farther away or
at a different angle (i.e., the intercept angle
is perceived as smaller than actual).
−
Runway approach aids:
The following runway approach-aids and conditions
may increase the crew exposure to visual illusions:
•
Offset localizer course; and/or,
•
2-bar VASI, if used below (typically) 300 ft
height above touchdown (HAT) for glide path
corrections.
!
When on top of a shallow fog layer, the
ground (or airport and runway, if flying
overhead) can be seen, but when
entering the fog layer the forward and
slant visibility usually are lost;
!
Entering a fog layer also creates the
perception of a pitch up, thus inducing a
tendency to push over and place the
aircraft below the desired glide path and
in a steeper-than-desired attitude;
In light rain or moderate rain, the runway
may also appear fuzzy because of rain halo
effect, increasing the risk of not perceiving
a vertical deviation or lateral deviation
during the visual segment.
The visual segment is defined as the
segment flown after full transition from
instruments to visual references;
Glide slope beam being unusable beyond a
specific point because of terrain or below a
specific altitude/height because of approach
over water;
•
Shallow fog (i.e., fog layer not exceeding
300 ft in thickness) results in a low
obscuration but also in low horizontal
visibility:
−
Weather conditions:
heavy rain affects depth perception and
distance perception:
!
Rain on windshields creates a refraction
and the perception of being too high,
thus inducing a nose down correction
that places the aircraft below the
desired flight path;
!
In daylight conditions, rain diminishes
the apparent intensity of the approach
lighting system (ALS) resulting in the
runway appearing to be farther away;
The following weather conditions may cause visual
illusions:
•
As a result of this illusion, the flightcrew
tends to shallow the flight path resulting
in a long landing;
Precipitation’s (e.g., rain, fog, snow):
−
−
Flying in light rain, fog , haze, mist, smoke,
dust, glare or darkness usually create an
illusion of being too high;
!
Flying in haze creates the impression that
the runway is farther away, inducing a
tendency to shallow the glide path and land
long;
Visual Illusions Awareness
Page 4
In night time conditions, rain increases
the apparent brilliance of the ALS,
making the runway appears to be
closer, inducing a pitch down input and
the risk of landing short of the runway
threshold.
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•
−
when breaking out of the overcast at both
ceiling and visibility minimums (DH and
RVR), the slant visibility may not allow sight
of the farther bar(s) of the VASI/PAPI, thus
reducing the available visual clues for the
visual segment in reduced visibility;
−
a snow-covered terrain together with a
clouds overcast create a phenomenon
called “white-out” that eliminate perception
of terrain features (slope) and height above
terrain.
The following table provides a summary of the
various factors and conditions together with their
effects on the pilot’s perception and actions:
Condition
Runway or
terrain
uphill slope
In crosswind conditions, the runway lights
and environment will be angled with the
aircraft heading; flight crew should maintain
the drift correction and resist the tendency
to align the aircraft heading with the runway
centerline.
Action
Result
Being too
high
Push
Land short /
land hard
Being too
low
Pull
Land long /
overrun
Wide
or
short runway
Runway or
terrain
downhill
slope
Runway surface condition (e.g., wet runway):
−
Perception
Narrow
or
long runway
Crosswind:
−
•
Getting to Grips with
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A wet runway does not reflect light, thus
affecting depth perception by appearing to
be farther away.
Pitch down
or
Duck under
-
-
Land short /
land hard /
CFIT
This visual effect usually results in a late
flare and in a firm touchdown.
Bright
runway
lighting
Being too
close
(too steep)
Push
Land short /
land hard
Low intensity
lighting
Being farther
away
(too shallow)
Pull
Land long /
overrun
Light rain,
fog, haze,
mist smoke,
dust
Being too
high
Push
Land short /
land hard
Entering fog
(shallow
layer)
Being pitch
up
Push
over
Steep
glide path /
( CFIT )
Flying in
haze
Being farther
away (too
shallow)
Pull
Land long /
overrun
Wet Runway
Being farther
away (too
high)
Late
flare
Hard
landing
Crosswind
Being
angled with
runway
Cancel
drift
Drifting
off track /
off runway
centerline
When landing on a wet runway, peripheral
vision of runway edge lights should be used
to increase the depth perception and
determine the flare point.
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How to Lessen the Effects of Visual
Illusions ?
Runway approach and visual aids:
− Type of approach (let-down aid restriction,
such as glide slope unusable beyond a
specific point or below a specific altitude);
To lessen the effects of visual illusions, prevention
strategies and lines-of-defense should be developed
and implemented based on the following
recommendations.
−
Type of approach lighting system; and,
Hazard Awareness
−
VASI or PAPI availability.
Operators should assess their exposure to visual
illusions in their operating environment (i.e., over the
entire route network).
Terrain awareness
When requesting or accepting a visual approach,
flight crew should be aware of the surrounding
terrain features and man-made obstacles.
Flight crews should be educated and trained on the
factors and conditions creating visual illusions and
their effects on the perception of the environment
and aircraft position:
•
Perception of heights / depth, distances, and
angles;
•
Assessment of aircraft lateral position and glide
path.
At night, an unlighted hillside between a lighted area
and the runway threshold may prevent the flight
crew from correctly perceiving the rising terrain.
Flying techniques
Type of approach
The awareness of visual illusions can be supported
by an identification of all hazard-airports and/or
hazard-runways (in the operator’s network) as a
function of the available navaids, visual aids and
prevailing hazards.
At night, when an instrument approach is available,
prefer this approach to a visual approach to reduce
the risk of accident caused by visual illusions:
•
ILS approach, with use of VASI / PAPI
(as available) for the visual segment; or,
•
Non-precision approach, supported by a VASI /
PAPI (as available).
Hazard Assessment
Approach hazards should be assessed for each
individual approach, during the approach and goaround briefing, by reviewing the following elements:
•
Ceiling and visibility conditions;
•
Weather:
•
−
wind, turbulence;
−
rain showers; and/or,
−
fog or smoke patches;
Crew experience
environment:
with
airport
and
On a non-precision approach, do not descend below
the
MDA(H)
before
reaching
the
visual
descent/decision point (VDP), even if adequate
visual references have been acquired before
reaching the VDP.
To prevent going too early to visual references and
descending prematurely below the MDA(H), the PF
should maintain reference to instruments until
reaching the VDP. This provides further protection
against visual illusions in hazard conditions.
airport
−
surrounding terrain; and/or,
−
specific airport and runway hazards
(obstructions, black-hole, off-airport light
patterns, …);
During a visual or circling approach, if the VASI /
PAPI indicates below glide slope level off or climb
until the VASI/PAPI shows on-glide-path.
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Flight path monitoring
Crew coordination
Resist the tendency to pitch down and “duck under”;
this is the greatest challenge during the visual
segment of the approach, this includes:
The defined task sharing ensures a continued
monitoring of visual and instrument references,
throughout the transition to visual references and
thereafter (i.e., during a visual approach or during
the visual segment of an instrument approach).
•
•
Pitching down into the approach light in an
attempt to see the runway during a precision
approach; or,
In known or anticipated hazard conditions, the PNF
should reinforce his / her monitoring of instrument
references and of flight progress, for an effective
cross-check and back-up of the PF.
Ducking under because of the impression of
being too high when affected by visual illusions.
Altitude and excessive-parameter-deviation callouts
should be the same for instrument approaches and
visual approaches, and should be continued during
the visual segment (i.e., including glide slope
deviation during an ILS approach or vertical speed
deviation during a non-precision approach).
Maintain a combination of visual flying supported by
monitoring of instruments (including the glide slope
deviation during the visual segment of an ILS
approach).
Monitor the VASI/PAPI, whenever available; this
provides additional visual cues to resist the
tendency to increase or decrease the rate of
descent.
In case of a go-around, specific excessiveparameter-deviation callouts should be considered
(as indicated in SOPs).
On runways equipped with an ALSF-II approach
lighting system, be aware of the two rows of red
lights aligned with the touchdown zone lights as an
additional safeguard against “ducking under”.
Typical Crew Actions and Results
The following crew actions and their consequences
often are cited in the analysis of approach-andlanding incidents or accident resulting from visual
illusions:
The following provides a summary of the techniques
available to counter visual illusions (and prevent
from ducking under):
•
Maintain instruments scan down to touchdown;
•
Cross-check instrument indications against
outside visual cues to confirm glide path;
•
Use an ILS approach, whenever available; and,
•
Use VASI / PAPI, if available, down to runway
threshold (only when using a 3-bar VASI or
a PAPI)
•
Use available references and indications such
as the ND extended runway centerline, the ILSDME (or VOR-DME) distance and the altitude
above airfield elevation to confirm the glide path
(based on a typically 300 ft-per-nm approach
gradient)
•
Unconscious modification of the aircraft
trajectory to keep a constant perception of visual
references;
•
Natural tendency to descend below the glide
slope or the initial glide path (i.e., “ducking
under”);
•
Inability to arrest the rate of descent after
descending below the intended glide path
(i.e., late recognition of the flattening of runway
and runway environment);
•
Absence of reference to instruments to support
the visual segment;
•
Failure to detect the deterioration of visual
references; and,
•
Failure to monitor the instruments and the flight
path, while both crewmembers are involved in
the identification of visual references.
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Summary of key points
The following
emphasized:
critical
keypoints
Regulatory References
need
to
be
•
Awareness of weather factors;
•
Awareness of surrounding terrain and obstacles;
•
Awareness and assessment of approach
hazards (i.e., conditions that may result in visual
illusions, such as “black hole”);
•
Adherence to defined PF/PNF task sharing for
acquisition of visual references and for flying the
visual segment; this includes:
•
ICAO – Preparation of an Operations Manual
(Doc 9376).
•
FAR 91.175 – Takeoff and landing under IFR –
Paragraph (b), Loss of visual references.
•
JAR-OPS 1 – Subpart E – All Weather
Operations - 1.1430 – Aerodrome Operating
Minima.
•
JAR-OPS 1 – Subpart E – All Weather
Operations - 1.435 - Terminology.
− monitoring by PF of outside visual cues while
transiently referring to instruments to support
and monitor the flight path during the visual
segment; and,
− monitoring by PNF of headdown cues for
effective cross-check and back-up (i.e., for
calling any excessive-parameter-deviation).
Associated Briefing Notes
The following Briefing Notes complement the above
discussion on the acquisition of visual references
and on visual illusions:
•
1.6 – Approach and Go-around Briefings.
•
5.2 – Terrain Awareness –
When and How ?
•
7.3 – Acquisition of Visual References.
•
7.4 – Flying Visual Approaches.
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Approach-and-Landing Briefing Note
5.4 – Wind Shear Awareness
Introduction
Defining Wind Shear
Flight crew awareness and alertness are key factors
in the successful application of wind shear
avoidance and escape / recovery techniques.
Wind shear is defined as a sudden change of wind
velocity and/or direction.
Two types wind shear can be encountered:
This Briefing Note provides an overview of
operational
recommendations
and
training
guidelines for aircraft operation in forecast or
suspected wind shear or downburst conditions.
•
Vertical wind shear:
−
vertical variations of the horizontal wind
component, resulting in turbulence that may
affect the aircraft airspeed when climbing or
descending through the wind shear layer;
−
vertical variations of
component of 20
30 kt-per-1000 ft are
vertical wind shear
10 kt-per-100 ft.
Statistical Data
Adverse weather (other than low visibility and
runway condition) is a circumstantial factor in nearly
40 % of approach-and-landing accidents.
Adverse wind conditions (i.e., strong cross winds,
tailwind and wind shear) are involved in more than
30 % of approach-and-landing accidents and in
15 % of events involving CFIT.
•
Horizontal wind shear:
−
horizontal variations of the wind component
(e.g., decreasing head wind or increasing
tail wind, or a shift from a head wind to a tail
wind), may affect the aircraft in level flight or
while climbing or descending;
−
horizontal variations of wind component
may reach up to 100 kt-per-nautical mile.
Wind shear is the primary causal factor in 4 % of
th
approach-and-landing accidents and is the 9 cause
of fatalities.
These statistical data are summarized in Table 1.
Factor
the horizontal wind
kt-per-1000 ft to
typical values, but a
may reach up to
Wind shear conditions usually are associated with
the following weather situations:
% of Events
Adverse weather
40 %
•
Jet streams;
Adverse wind (all conditions)
33 %
•
Mountain waves;
Wind shear
4%
•
Frontal surfaces;
•
Thunderstorms and convective clouds; and,
•
Microbursts.
Table 1
Weather factors in Approach-and-Landing Accidents
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•
Microbursts combine two distinct threats to aviation
safety:
•
The downburst part, resulting in strong
downdrafts (reaching up to 40 kt of vertical
velocity); and,
•
The outburst part, resulting in large horizontal
wind shear and wind component shift from head
wind to tail wind (horizontal winds may reach up
to 100 kt).
Visual observation:
−
•
On-board wind component and ground speed
monitoring:
−
Wind Shear Avoidance
The following information should be used to avoid
areas of potential or observed wind shear:
•
Weather reports and forecast:
−
The low level wind shear alert system
(LLWAS) allows controllers to warn pilots of
existing or impending wind shear conditions.
Blowing dust, rings of dust, dust devils (i.e.,
whirlwinds containing dust and stand), or
any other evidence of strong local air
outflow near the surface often are indication
of potential or existing wind shear.
On approach, a comparison of the head
wind or tail wind component aloft (as
available) and the surface head or tail wind
component indicates the potential and likely
degree of vertical wind shear.
•
On-board weather radar; and,
•
On-board predictive wind shear system.
LLWAS consists of a central wind sensor
(sensing wind velocity and direction) and
peripheral wind sensors located at
approximately 2 nm from the center.
Center wind sensor data are averaged over
a rolling 2-minute period and compared
every 10 seconds to the data of the
peripheral wind sensors.
An alert is generated whenever a difference
in excess of 15 kt is detected.
Photo Credit : SFENA - Sextant Avionics
LLWAS may not detect downbursts with a
diameter of 2 nm or less.
−
•
A Terminal Doppler Weather Radar
(TDWR) allows to detect approaching wind
shear areas and, thus, to provide pilots with
more advance warning of wind shear
hazard.
Wind Shear Recognition
Timely recognition of a wind shear condition is vital
for the successful implementation of the wind shear
recovery/escape procedure.
Pilot’s reports:
−
The aircraft flight envelope protection provides an
automatic detection of a wind shear condition during
takeoff, approach or go-around, based on the
assessment of the aircraft performance (flight
parameters and accelerations).
PIREPS of wind shear in excess of 20 kt or
downdraft / updraft of 500 ft/mn below
1000 ft above airfield elevation should be
cause for caution.
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The following deviations should be considered as
indications of a possible wind shear condition:
•
Indicated airspeed variations in excess of 15 kt;
•
Ground speed variations (decreasing head wind
or increasing tail wind or shift from head wind to
tail wind);
•
Vertical speed excursions of 500 ft/mn;
•
Pitch attitude excursions of 5 degrees;
•
Glide slope deviation of 1 dot;
•
Heading variations of 10 degrees;
•
Unusual autothrottle activity or throttle levers
position.
If the FD windshear guidance is not available
(e.g., FD not available) a similar recovery technique
is recommended and published in the applicable
FCOM.
Reactive and
Warnings
Predictive
Wind
Shear
In addition to the FD wind-shear-survival guidance,
an optional WINDSHEAR warning is available on
most aircraft models.
The wind shear warning and the FD survival
guidance are activated only when a wind shear
condition is detected based on the assessment of
aircraft performance (flight parameters and
accelerations).
Wind Shear Survival Strategy
The wind shear warning and guidance therefore are
called Reactive Wind Shear Systems, because they
do not incorporate any forward looking and
anticipation capability.
In case of wind shear encounter, a survival strategy
needs to be adopted to minimize the altitude loss
and the associated risk of ground contact.
The following describes the wind shear survival
strategy implemented in the flight director (FD) for
conventional aircraft models.
To complement the reactive wind shear systems
and provide an early warning of wind shear activity,
the last generation of weather radars features
the capability to detect wind shear areas ahead of
the aircraft.
The FD wind shear recovery guidance attempts to:
•
Maintain the speed target (speed selected on
FCU + 10 kt) as long as a positive vertical
speed is possible;
This new equipment is referred to as a Predictive
Wind Shear System.
•
Adjust the pitch attitude as the vertical speed
decreases towards zero;
Predictive wind shear systems provide typically a
one-minute advance warning.
•
Maintain a slightly positive vertical speed until
airspeed decreases to the boundary of the stickshaker (intermittent stick shaker activation);
then,
Predictive wind shear systems generate three levels
of wind shear alert:
•
Maintain the airspeed slightly above the stick
shaker boundary, allowing an altitude loss as
long as required for maintaining the stick-shaker
speed.
The wind shear guidance is available at takeoff, in
approach and during a go-around, when below
1000 ft RA.
•
Advisory alert voice messages;
•
Amber caution (W/S AHEAD); or,
•
Red warning (W/S AHEAD).
Colored patterns and icons are displayed on the
weather radar display (ND) to indicate areas of
windshear activity.
The pitch attitude demand is limited by the stall
protection during all the phases of the above
survival strategy.
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The wind shear survival / escape procedure should
be trained in a full-flight simulator, using realistic
wind shear profiles recorded during actual wind
shear encounters (as illustrated by Figure 1).
Wind Shear Awareness
The following are opportunities to enhance:
•
Wind shear awareness; and,
•
Operational recommendations and procedures.
Standard Operating Procedures
Standard operating procedures (SOPs) should
emphasize the following wind-shear-awareness
items:
•
•
Wind shear awareness and avoidance :
−
Takeoff / departure and
go-around briefings; and,
−
Approach hazards awareness.
/
Photo Credit : SFENA - Sextant Avionics
Wind shear recognition:
−
•
approach
Task sharing for effective cross-check and
back-up,
particularly
for
excessive
parameter-deviations;
−
Energy management during approach; and,
−
Elements of a stabilized approach and
approach gates.
Figure 1
Wind Shear Profile - Typical
Cockpit Preparation – Departure Briefing
Flight crew should consider all available wind shearawareness-items and:
Wind shear survival / escape procedure:
−
Readiness and commitment to respond to
a reactive or predictive wind shear advisory
or warning, as available (wind shear survival
/ escape).
•
Training
A wind shear awareness program should be
developed and implemented, based on the contents
of:
•
The industry-developed Wind Shear Education
and Training Aid; and,
•
The
Flight
Safety Foundation-developed
Windshear Training Package.
•
Assess the conditions for a safe takeoff based
on:
−
Most recent weather reports and forecast;
−
Visual observations; and,
−
Crew
experience
with
the
airport
environment and the prevailing weather
conditions; or,
Delay the takeoff until conditions improve, as
warranted.
Wind Shear Awareness
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−
Takeoff and initial climb
If wind shear conditions are suspected during
takeoff, the flight crew should:
•
Select the most favorable runway, considering
the location of the likely wind shear / downburst;
•
follow the flight director pitch orders (wind
shear survival guidance) or set the required
pitch attitude, if FD is not available (as
recommended in the applicable FCOM).
During initial climb:
•
Select the minimum flaps configuration
compatible with takeoff requirements, to
maximize the climb-gradient capability;
−
disconnect
the
autothrottle/autothrust
(A/THR) and maintain or set the throttle
levers to the maximum takeoff thrust;
•
Use the weather radar (or the predictive wind
shear system, as available) before commencing
the takeoff roll to ensure that the flight path is
clear of potential hazard areas;
−
if the autopilot (AP) is engaged, keep the
AP engaged;
or,
follow the FD pitch orders,
•
Select the maximum takeoff thrust;
or,
•
After triggering the go levers ( setting TOGA ),
select the flight path vector display on the PNF
ND, as available, to obtain a direct visual cue of
the climb flight path angle; and,
set
the
required
pitch
attitude
(as recommended in the applicable FCOM);
•
Closely monitor the airspeed and speed trend
during the takeoff roll to detect any evidence of
impending wind shear.
Recovery technique for wind shear encounter
during takeoff
−
level the wings to maximize climb gradient,
unless a turn is required for obstacle
clearance;
−
closely monitor the airspeed, speed trend
and flight path angle (as available);
−
allow airspeed to decrease to stick shaker
activation boundary (intermittent stick
shaker activation) while monitoring speed
trend;
If wind shear is encountered during takeoff roll or
during initial climb, apply the following recovery
techniques without delay:
•
−
•
(reference to stick shaker applies only to
conventional aircraft models)
Before V1:
reject the takeoff only if unacceptable
airspeed variations occur (not exceeding
the target V1) and if there is sufficient
runway remaining to stop the airplane.
After V1:
−
disconnect
the
autothrottle/autothrust
(A/THR) and maintain or set the
throttle/thrust levers to the maximum takeoff
thrust;
−
rotate normally at V R; and,
−
do not change the flaps and gear
configuration until out of the wind shear
condition;
−
when out of the wind shear condition,
increase the airspeed when a positive climb
is confirmed, retract landing gear and
flaps/slats (as applicable), and then recover
a normal climb profile.
Wind Shear Awareness
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Descent Preparation
Go-around Briefing
–
Getting to Grips with
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Approach
•
and
An expanded review of the wind shear-awarenessitems to be covered in the approach briefing – as
practical and appropriate for the conditions of the
flight – is provided hereafter.
•
•
−
Expected arrival route (standard arrival –
STAR - or more direct radar vectors);
−
Prevailing weather;
−
Reports of potential low level wind shear
(LLWAS warnings, TDRS data, PIREPS).
•
Select less than full flaps for landing (to
maximize the climb-gradient capability) and
adjust the final approach speed accordingly;
•
If an ILS is available, engage the autopilot for a
more accurate approach tracking and for taking
benefit of the glide slope excessive-deviationwarning;
•
Select a final approach speed based on the
reported surface wind;
A speed increment is recommended (usually up
to 15 kt to 20 kt, based on the anticipated wind
shear value);
Before conducting an approach in forecast or
suspected wind shear conditions, the flight crew
should:
•
•
Compare the head wind component or tail wind
component aloft and the surface head wind or
tail wind component to assess the potential and
likely degree of vertical wind shear;
•
Closely monitor the airspeed, speed trend and
ground speed during the approach to detect any
evidence of impending wind shear;
Assess the conditions for a safe approach and
landing based on:
−
Most recent weather reports and forecast;
−
Visual observations; and,
−
Crew
experience
with
the
airport
environment and the prevailing weather
conditions.
the available runway approach aids.
Select the flight path vector display on the PNF
ND to obtain a direct visual cue of the flight path
angle (during the approach or during the
recovery/escape maneuver).
Descent and Approach
•
−
•
Use of automation:
Discuss the intended use of automation for
vertical and lateral navigation as a function of
the suspected or forecast wind shear conditions.
the location of the likely wind shear /
downburst condition; and,
Use the weather radar (or the predictive wind
shear system, as available) during the approach
to ensure that the flight path is clear of potential
hazard areas;
Review and discuss the following items:
Runway in use (type of approach);
−
•
ATIS:
−
Select the most favorable runway, considering:
Microbursts are characterized by a significant
increase of the headwind component preceding
a sudden change to a tailwind component,
whenever wind shear is anticipated closely
monitor the ground speed enhanced wind shear
awareness;
Delay the approach and landing until conditions
improve or divert to a suitable airport;
When downburst / wind shear conditions are
anticipated based on pilot’s reports from
preceding aircraft or based on an alert issued by
the airport low level wind shear alert system
(LLWAS), the landing should be delayed or the
aircraft should divert to the destination alternate
airport.
If ground speed decreases (i.e., increasing
head wind), maintain a ground speed not lower
than V APP – 10 kt to maintain the aircraft
energy level in case of sudden head wind to tail
wind change.
Wind Shear Awareness
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•
Getting to Grips with
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Be alert to respond without delay to :
Factors Affecting Wind Shear Awareness
−
Any predictive windshear advisory, W/S
AHEAD caution or W/S AHEAD warning;
and/or,
The following factors may affect the wind shear
awareness and avoidance or the survival capability.
−
A reactive WINDSHEAR warning.
Prevention strategies and lines-of-defense should
be developed to address these adverse factors
(as possible and practical):
•
For respective W/S AHEAD and WINDSHEAR
procedures, refer to the applicable FCOM and QRH.
−
•
Recovery technique for wind shear encounter
during approach and landing
If wind shear is encountered during the approach or
landing, the following recovery techniques should be
implemented without delay:
•
Aircraft equipment:
Trigger the go-around levers (or set thrust
levers to TOGA, as applicable) and maintain the
maximum go-around thrust;
•
absence of reactive and/or predictive wind
shear system(s).
Airport equipment:
−
Absence of a low level wind shear alert
system (LLWAS) detection and warning
system; and/or,
−
Absence of a terminal Doppler radar system
(TDRS).
Training :
•
Follow the FD pitch orders or set the pitch
attitude target recommended in the FCOM (if
FD is not available);
−
Absence of wind shear awareness program;
and/or,
•
If the AP is engaged keep the AP engaged.
−
Absence of simulator training for wind shear
recovery.
As required, disconnect the AP and follow the
FD orders, or set and maintain the
recommended pitch attitude;
•
•
•
•
•
•
Do not change the flaps and landing gear
configuration until out of the wind shear
condition;
Level the wings to maximize climb gradient,
unless a turn is required for obstacle clearance;
Allow airspeed to decrease to stick shaker
activation boundary (intermittent stick shaker
activation – conventional aircraft only) while
monitoring speed trend;
•
Closely monitor the airspeed, speed trend and
flight path angle (if flight path vector is available
and displayed for the PNF); and,
When out of the wind shear condition, increase
the airspeed when a positive climb is confirmed
then establish a normal climb profile.
Standard operating procedures:
−
Inadequate briefings;
−
Inadequate monitoring of flight progress;
and/or,
−
Incorrect use
automation.
or
interaction
with
Human Factors and CRM:
−
Absence of crosscheck (for excessive
parameter-deviations);
−
Inadequate back-up (callouts); and/or,
−
Fatigue.
Wind Shear Awareness
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Summary of Key Points
Associated Briefing Notes
The following key points and recommendations
should be considered in the development of
company strategies and initiatives enhancing wind
shear awareness.
The following Briefing Notes provide expanded
information on related subjects:
•
1.1 – Operating Philosophy – SOPs,
•
1.2 – Optimum Use of Automation,
•
1.3 - Operations Golden Rules,
•
1.4 – Standard Calls,
Avoidance
•
1.6 – Approach and Go-around Briefing,
−
•
5.1 – Approach Hazards Awareness,
•
6.1 – Being Prepared for Go-around.
Keypoints are grouped into the three domains
associated with wind shear awareness; Avoidance,
Recognition and Recovery / Escape.
•
•
−
Delay the takeoff or the approach, or divert
to a more suitable airport; and,
−
Be prepared and committed for an
immediate response to a predictive wind
shear advisory/caution/warning or to a
reactive wind shear warning.
Regulatory References
The following regulatory references are provided to
assist the reader in a quick and easy reference to
the related regulatory material:
•
ICAO – Preparation of an Operations Manual
(Doc 9376).
Be alert to recognize a potential or existing
wind shear condition, based on all the
available weather data, on-board equipment
and on the monitoring of the aircraft flight
parameters and flight path; and,
•
ICAO – Windshear (Circular 186).
•
ICAO Annex 6 – Part I, 6.26 –
Recommendation, Turbo-jet airplanes –
Forward-looking wind shear warning system.
Enhance instruments scan, whenever
potential wind shear is suspected.
•
FAR 121.135 – Manual Requirements –
Operations Manual – Contents.
Recovery / Escape
•
FAR 121.315 – Cockpit check procedure.
−
Avoid large thrust variations or trim changes
in response to sudden airspeed variations;
•
FAR 121.357 – Airborne weather radar
equipment requirements.
−
Follow the FD wind shear recovery/escape
pitch-guidance or apply the recommended
FCOM recovery/escape procedure; and,
•
FAR 121.358 – Low-altitude wind shear system
equipment requirements.
•
−
Make maximum use of aircraft equipment,
such as the flight path vector (as available).
FAR 121.360 – Ground proximity warning –
glide slope deviation alerting system.
•
FAR 121.424 (b).(1) – Pilots: Initial, transition,
and upgrade flight training – Wind shear
maneuvers.
Recognition
−
−
•
Assess the conditions for a safe takeoff or
approach-and-landing, based on all the
available meteorological data, visual
observations and on-board equipment;
Wind Shear Awareness
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Getting to Grips with
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Other References
FAR 121.542 – Flight crewmember duties
(sterile cockpit rule).
•
FAR 121.599 – Familiarity with weather
conditions.
•
FAA – AC 00-54 - Pilot Wind Shear Guide.
The industry-developed Wind Shear Training Aid
should be used to further illustrate and complement
the information contained in these Briefing Notes.
The two-volume Wind Shear Training Aid is
available from:
U.S. National Technical Information Service
(NTIS),
5285 Port Royal Road
Springfield, VA 22161 U.S.A.,
Telephone: 800-553-6847 (U.S.)
or
+1 703-605-6000,
Fax: +1 703-605-6900,
Internet site: htttp://www.ntis.gov.
Photo Credit : SFENA - Sextant Avionics
Wind Shear Awareness
Page 9
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Flight Operations Support
Getting to Grips with
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Chapter 6
Readiness and Commitment to Go-around
AIRBUS INDUSTRIE
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Approach-and-Landing Briefing Note
6.1 - Being Prepared to Go Around
Introduction
Statistical Data
Failure to recognize the need for and to execute a
go-around and missed-approach when appropriate is
a major cause of approach-and-landing accidents.
More than 70 % of approach-and-landing accidents
contain elements which should have been recognized
by the crew as improper and which should have
prompted a go-around.
Because a go-around is not a frequent occurrence,
the importance of being go-around-prepared and
being go-around-minded must be emphasized.
Inadequate assertiveness and/or decision-making are
causal factors in 75 % of events
To be go-around-prepared and go-around-minded the
flight crew should:
•
Have a clear mental image of applicable briefings,
sequences of actions, task sharing, standard
calls and excessive-deviation callouts;
•
Be ready to abandon the approach if:
•
§
Ceiling and/or visibility (RVR) are below the
required weather minimums;
§
Criteria for a stabilized approach are not
achieved;
§
Doubt exists about the aircraft position;
and/or,
§
Confusion exists
automation;
about
the
use
In only 17 % of rushed and unstabilized approaches,
analyzed by the approach-and-landing accidents
reduction task force, the flight crew initiated
a go-around when conditions clearly dictated that
a go-around was required by:
of
•
An unstabilized approach;
•
Excessive glideslope and/or localizer deviation;
•
Absence of adequate visual references at the
MDA(H) or DA(H);
•
Confusion regarding aircraft position; and/or,
•
Automation-interaction.
Operational Recommendations
After the go-around is initiated, be fully
committed to fly the published missed-approach
procedure.
Task Sharing:
The chain of events resulting in a go-around often
starts at the top-of-descent; this Briefing Note
therefore provides an overview of operational
recommendations starting from the descent
preparation and approach briefing.
Strict adherence to the defined PF/PNF task sharing
is the most important factor to conduct a safe
go-around; this includes task sharing for:
•
Hand flying or flying with AP engaged; and/or,
•
Normal operation or abnormal / emergency
conditions.
Being Prepared to Go Around
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The following Briefing Notes provide expanded
information on PF / PNF task sharing:
•
1.1 – Operating Philosophy - SOPs,
•
1.3 - Operations Golden Rules,
•
1.4 - Standard Calls,
•
6.2 - Flying a Manual Go-around,
•
7.3 - Acquisition of Visual References.
Concept of next target:
Throughout the entire flight a next target should be
defined at all times to stay ahead of the aircraft.
During the descent, approach and landing phases,
successive next targets should be defined and
immediate corrective action(s) should be taken if it
anticipated that one elem ent of the next target would
not be achieved.
Refer to Briefing Note 4.1 - Descent Profile
Management for detailed information.
Descent Preparation:
The descent preparation and the approach / goaround briefing should be planned and conducted in a
timely manner in order to prevent any delay in the
initiation of the descent and any rush in the
management of the descent profile.
Descent Monitoring:
The descent profile should be monitored, using all
available instrument references (e.g., including the
FMS vertical deviation, as applicable).
Approach / Go-around Briefing:
If flight path is significantly above the desired descent
profile (e.g. because of ATC constraint or because of
a higher-than-anticipated tail wind) the desired flight
path can be recovered by:
To be go-around prepared, a formal go-around briefing
should be conducted highlighting the key points of:
•
Go-around maneuver; and,
•
Published missed-approach procedure.
•
Maintaining a high airspeed ( as long as practical
);
The go-around part of the approach briefing should
recall the following key aspects:
•
Using speed brakes;
•
•
Extending the landing gear, if the use of speed
brakes is not sufficient; and,
•
As a last resort, perform a 360-degree turn (as
practical and cleared by ATC).
Target stabilization point, e.g.;
−
3000 ft above airfield elevation;
−
15 nautical mile from touchdown; and,
−
clean maneuvering speed (green dot speed);
•
Go-around standard call (e.g., a loud and clear
Go Around / Flaps call);
•
PF / PNF task sharing (i.e., flow of respective
actions, including desired guidance – mode
engagement – speed target, go-around altitude,
deviations callout); and,
•
If the desired descent flight path cannot be recovered,
ATC should be notified for timely coordination.
Refer to Briefing Notes for expanded information:
Missed-approach vertical and lateral navigation
(including speed and altitude restrictions).
•
4.1 - Descent Profile Management ; and,
•
4.2 - Energy Management during Approach.
See also Briefing Note 1.6 – Approach and
Go-around Briefings , for expanded information.
Being Prepared to Go Around
Page 2
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Final Approach:
(this concept is described in Briefing
7.3 - Acquisition of Visual References).
Because the approach briefing is performed at the
end of cruise, the crew may briefly recall the main
points of the go-around and missed-approach at an
appropriate time during the final approach.
When flying with the AP engaged, the following
aspects should be considered to be ready to take
over manually:
•
Seat and armrest adjustment ( this is of primary
importance for an effective handling of the aircraft
in a dynamic phase of flight ); and,
•
Flying with one hand on the control wheel (or
side stick, as applicable) and one hand on the
throttle levers (thrust levers).
Go-around - Transition back to IMC:
The most frequent reason for performing
a go-around is related to weather minima.
When approaching the MDA(H) or the DA(H), one
crewmember is attempting to acquire the required
visual references. During this period of time, this
crewmember is in almost-visual flying conditions.
The task sharing for the acquisition of visual
references is discussed and expanded in Briefing
Note 7.3 - Acquisition of Visual References.
If a go-around is initiated, an immediate transition
back to instrument flying must take place.
The other crewmember therefore must maintain
instrument references and be ready to make
appropriate callouts if one flight parameter (speed,
pitch attitude, bank angle, thrust) deviates from the
normal and safe value.
To ease this transition, all efforts should be made to
initiate the go-around with wings level and with
no roll rate.
This transition from almost-VMC back to IMC does
not apply when a CAPT-F/O task sharing is
implemented in accordance with the concept known
as Shared approach or Monitored approach or
Delegated handling approach.
Being Prepared to Go Around
Page 3
Note
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Summary of key points
•
FAR 91.175 – Takeoff and landing under IFR –
requirement for immediate go-around in case of
loss of visual references when below MDA(H) or
DA(H) during a non-precision or CAT I ILS
approach.
If the criteria for a safe continuation of the approach
are
not
met,
the
crew
should
be
go-around-committed, initiate a go-around and fly
the published missed-approach.
•
FAR 91.189 – Category II and III operations:
General operating rules – requirement for
immediate go-around in case of loss of visual
references when below DA(H) during a CAT II or
CAT III ILS approach.
Associated Briefing Notes
•
FAA AC 60-A – Pilot’s Spatial Disorientation.
Because a go-around is not a frequent occurrence,
the importance of being go-around-prepared and
go-around-minded should be emphasized.
The following Briefing Notes should be reviewed to
complement the above information:
•
6.2 - Flying a Manual Go-around,
•
1.1 – Operating Philosophy - SOPs,
•
1.3 - Operations Golden Rules,
•
1.4 - Standard Calls,
•
1.6 - Approach and Go-around Briefings,
•
4.1 - Descent and Approach Profile
Management,
•
4.2 - Energy Management during
Approach,
•
7.1 - Flying Stabilized Approaches,
•
7.3 - Acquisition of Visual References.
Regulatory references
•
ICAO – Annex 6 – Operation of Aircraft, Part I –
International Commercial Air Transport –
Aeroplanes, Appendix 2. 5.16, 5.18, 5.19.
•
ICAO – Procedures for Air navigation Services –
Aircraft Operations (PANS-OPS), Doc 8168),
Volume I – Flight Procedures.
•
ICAO – Manual of All-Weather
(Doc 9365).
Operations
Being Prepared to Go Around
Page 4
AIRBUS INDUSTRIE
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Getting to Grips with
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Approach-and-Landing Briefing Note
6.2 - Flying a Manual Go-around
Introduction
Recommendations
Because a go-around is not a frequent occurrence,
the importance of being go-around-prepared and
go-around-minded must be emphasized.
PF / PNF Task Sharing:
Strict adherence to task-sharing principles is
particularly important in the very dynamic phase
associated with initiating a go-around.
To be go-around-prepared and go-around-minded the
flight crew should:
•
Have a clear mental image of applicable
briefings, sequences of actions, task sharing,
standard calls and excessive -deviation callouts;
•
Be ready to abandon the approach if:
§
Ceiling and/or visibility (RVR) are below the
required minimums;
§
Criteria for a stabilized approach are not
achieved;
§
Doubt exists about the aircraft position;
and/or,
§
Confusion exists
automation.
about
the
use
The PF is responsible for controlling the vertical flight
path
and
lateral
flight
path
and
for energy management, by either:
•
Supervising the autopilot vertical guidance and
lateral guidance and the autothrottle/autothrust
operation (i.e., awareness of the modes being
armed or engaged and of mode changes, and
awareness of selected targets);
or,
•
Flying manually, with FD guidance.
If manual thrust is selected, the PNF should
monitor the speed, speed trend and thrust
closely, and call any parameter excessivedeviation.
of
The PNF is responsible for monitoring tasks and for
performing the actions requested by the PF, this
includes:
See also Briefing Note 6.1 - Being Prepared for Goaround.
If the conditions for a safe approach and landing are
not
met,
the
flight
crew
should
be
go-around-committed; initiate a go-around and fly
the missed-approach procedure as published
(i.e., following the published vertical profile and lateral
navigation or as directed by ATC).
This Briefing Note provides an overview of the flying
techniques and procedures recommended for
the safe conduct of a manual go-around.
•
Monitoring vertical speed and radio altitude;
•
Monitoring pitch attitude, bank angle, speed and
speed trend, and calling any parameter
excessive-deviation;
•
Monitoring thrust;
•
SOP actions and normal checklists;
Flying a Manual Go-around
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•
Actions on FCU or FMS CDU, when in manual
flight; and,
•
Abnormal or emergency checklists
actions and/or QRH procedures ).
Understanding
the
of the go- around:
flight
As a result of these three nose up effects:
The pitch attitude and pitch rate increase; and,
•
The nose up pitch-force required to maintain
the target pitch attitude, decreases until a nose
down pitch force is required to prevent from
reaching an excessive pitch attitude.
dynamics
To maintain the desired pitch attitude target (and
prevent exceeding this target), the PF must therefore:
Note :
The following overview and discussion mainly apply to
conventional
aircraft
models.
Nevertheless,
the basic principles of flight and pitching effects
need to be understood by pilots operating aircraft
models with fly-by-wire controls and protections.
During rotation for takeoff, the aircraft
pre-trimmed and the thrust is already set.
•
Release the backward (nose up) input on the
control column (side stick);
•
Apply progressively an increasing forward (nose
down) input on the control column (side stick), as
the thrust increases; and,
•
Re-trim the aircraft (nose down), as necessary.
is
The initiation of a go-around involves a very dynamic
sequence
of
actions
and
changes
(i.e., thrust increase, configuration change) affecting
the pitch balance.
(on conventional aircraft models only).
The PF should simp ly fly the aircraft while closely
monitoring the PFD.
These effects are amplified:
•
At low gross-weight, low altitude and low outside
air temperature (hence, at high thrust-to-weight
ratio); and/or,
•
With all-engines-operative, as compared to a
one-engine-inoperative go-around.
If the pitch is not positively controlled,
the pitch attitude continues to increase until a
significant speed loss occurs, despite the go-around
thrust.
Flying a manual go-around maneuver:
When initiating a go-around at DA(H), the PF is
expected to minimize the altitude loss.
To conduct a safe go-around, the flight crew should
prioritize the elements of the following 3-Ps rule:
•
Therefore, the PF must simultaneously apply a nose
up pitch command on the control column (side stick)
and trigger the go-around levers (set TOGA):
•
This first (nose up) elevator input initiates a pitch
attitude change that minimizes the altitude loss;
•
Within a few seconds, the thrust increase
creates an additional nose up effect (because of
the pitching effect of underwing-mounted
engines);
•
•
(ECAM
Pitch :
−
•
set and maintain the target pitch attitude;
Power :
− set and check the go-around thrust; and,
•
Performance :
− check the aircraft performance: positive rate of
climb, speed at or above V APP, speed brakes
retracted, radio-altimeter and baro-altimeter
indications increasing, wings level, no roll
rate, gear up, flaps as required.
Retracting one step of flaps also results in
a slight nose up pitching effect.
Flying a Manual Go-around
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•
The operational recommendations and task sharing
for the safe conduct of a manual go-around can be
expanded as follows:
If a high pitch attitude is inadvertently reached,
an immediate and firm elevator nose down input
(together with a nose down pitch trim order, on
conventional aircraft models) must be applied to
recover the target pitch attitude.
For the PF :
•
When calling “ Go-around / Flaps “, without
delay :
− trigger the go-around levers (set TOGA) and
follow-through the A/THR operation;
For the PNF :
− rotate (at the same rate as for a takeoff
rotation, typically 3 degrees per second);
•
− follow the FD Pitch command (not exceeding
the maximum pitch attitude applicable for the
aircraft type, typically 18 degrees);
− check the FMA :
− check go-around Performance :
§
positive rate of climb;
§
speed at or above V APP;
§
speed brakes retracted;
§
radio-altimeter and barometric-altimeter
indications increasing;
§
wings level, no roll rate;
§
gear up; and,
§
flaps as required.
§
§
•
•
loudly
the
FMA,
§
thrust, vertical and
engagement; and,
§
AP / FD engagement status;
lateral
modes
− announce loudly the FMA, unless announced
by PF:
§
THR (thrust) mode, vertical and lateral
modes engaged; and,
§
AP/FD status (i.e. AP engaged or hand
flying with FD guidance);
conditions
− announce “ Positive Climb “ and retract the
landing gear, on PF command;
THR (thrust) mode, vertical and lateral
modes engaged; and,
− monitor :
AP/FD status (i.e. AP engaged or hand
flying with FD guidance);
As thrust increases, be prepared to counteract
the thrust nose up pitching effect (i.e. apply an
increasing forward pressure – nose-down input on the control column/side stick);
Trim the aircraft nose down,
(conventional aircraft models only);
When hearing the “ Go-around – Flaps “ call,
without delay :
− retract one step of flaps, as applicable;
− check go-around Power ( thrust );
− announce
permitting:
Do not allow the pitch attitude to exceed
an ultimate value (e.g. 25 degrees ), because
a significant speed loss would occur;
as
§
the airspeed and speed trend,
§
the pitch attitude and bank angle,
§
the thrust increase (confirm the thrust limit
mode, as applicable, and the actual thrust
on N1/EPR indicators ),
required
Flying a Manual Go-around
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− continue monitoring the flight parameters and
call any excessive parameter deviation :
Strict adherence to the defined PF / PNF task
sharing and to crew resources management
principles should be emphasized for;
§
“ speed “, if airspeed decreases below V
APP – 5 kt;
•
Monitoring of flight and callout of any flight
parameter excessive -deviation; or,
§
“ speed trend “, if negative;
•
Management of any warning or other unexpected
occurrences.
§
“ pitch “, if pitch attitude exceeds
20 degrees;
§
“ bank “, if bank angle exceeds
15 degrees ( 30 degrees if the missedapproach procedure requires a turn );
and/or,
§
“ thrust “, if a significant thrust loss is
observed.
If a warning is activated or if any other abnormal
condition
occurs
during
the
go-around,
the PF must concentrate his/her attention on flying
the aircraft (i.e., vertical flight path and lateral flight
path).
The manual go-around technique must:
•
Minimize the initial altitude loss;
•
Prevent an excessive pitch attitude by :
Summary of key points
− following FD pitch commands (SRS orders),
not exceeding 18-degrees pitch attitude ;
For a safe go-around, strictly adhere to the following
3-Ps rule :
•
− considering a 25-degree pitch attitude as an
ultimate barrier from which the pilot should
return immediately.
Pitch :
− set and maintain the target pitch attitude;
•
Associated Briefing Notes
Power :
− set and check go-around thrust; and,
•
The following Briefing Notes should be reviewed to
further expand the above inform ation:
Performance :
− check / confirm aircraft performance :
•
1.1 - Standard Operating Procedures,
§
positive rate of climb;
•
1.3 - Operations Golden Rules,
§
speed at or above V APP;
•
1.4 - Standard Calls,
§
speed brakes retracted;
•
4.1 – Descent and Approach Management,
§
radio-altimeter and barometric-altimeter
indications increasing;
•
4.2 – Energy Management during Approach,
§
wings level and no roll rate;
•
6.1 - Being Prepared for Go-around,
§
gear up; and,
•
7.1 - Flying Stabilized Approaches.
§
flaps as required.
Flying a Manual Go-around
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Regulatory References
•
ICAO – Annex 6 – Operation of Aircraft, Part I –
International Commercial Air transport –
Aeroplanes, Appendix 2, 5.14, 5.16, 5.18, 5.21
and 5.22.
•
ICAO – Preparations of an Operations Manual
(Doc 9376).
Speed
If dropping below VAPP - 5 kt
Speed trend
If negative
Pitch attitude
If in excess of 20° nose up
Bank angle
If in excess of 15°
Thrust
If significant thrust loss
Figure 1
Excessive Deviation Callouts in Go-around
Flying a Manual Go-around
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Approach-and-Landing Briefing Note
6.3 - Response to GPWS – Pull-Up Maneuver Training
Introduction
Factor
A typical awareness and training program for the
reduction
of
approach-and-landing
accidents
involving controlled-flight-into-terrain (CFIT) should
include the following:
GPWS installed:
40 %
- late crew response; or,
•
Educate flight crews on the factors that may
cause CFIT;
•
Ensure that horizontal situational awareness and
vertical situational awareness is maintained at all
times (SOPs);
GPWS installed:
Ensure that flight crews attain proficiency in the
execution of the approach procedures and
techniques recommended for their aircraft type;
GPWS not installed
•
•
•
% of Events
- inadequate crew response
30 %
- no warning
30 %
Table 1
Provide pilots with an adequate understanding of
the capability and limitations of the GPWS and
EGPWS / TAWS installed on their aircraft; and,
GPWS Factors in CFIT Events
( Circa 1996 )
Ensure that pilots are proficient in performing the
terrain avoidance maneuver required in response
to a GPWS or EGPWS / TAWS warning
(Figure 3 and Figure 4 and applicable FCOM /
QRH).
Training Program Outline
The transition training and recurrent training should
emphasized the following, during descent and
approach:
•
CFIT events account for approximately 45 % of all
approach-and-landing accidents and are the leading
cause of fatalities.
Strict adherence to SOPs (e.g., standard calls)
to re-inforce the horizontal situational awareness
and vertical situational awareness;
•
Optimum use of automated systems and cockpit
displays.
Figure 1 shows that 70 % of CFIT events could have
been avoided by:
The CFIT prevention-training program recommended
hereafter further supports these objectives.
•
Installation of a GPWS; or,
•
An immediate and
the GPWS warning.
This program is designed to be integrated into the
standard transition-training course and/or recurrenttraining course developed by Airbus Industrie or
developed by the airline’s training department.
Statistical Data
adequate
response
to
Response to GPWS/TAWS – Pull-Up Maneuver Training
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•
The recommended program consists of:
•
•
•
A classroom briefing or a self-briefing session
based on the contents of:
−
the Airbus Industrie CFIT Education and
Training Aid;
−
the relevant Approach-and-Landing Briefing
Notes and presentations;
−
the description and operations of the
applicable model of GPWS and EGPWS /
TAWS ( FCOM and QRH ).
Nevertheless, inserting an electronic mountain at
an airport that does not feature such terrain may
result in the trainee dismissing the (E)GPWS /
TAWS warning (assuming a spurious warning),
thus resulting in negative training.
The slope and height of the mountain should be
tailored to the particular aircraft performance
capability
at
a
representative
weight
(e.g. maximum landing weight), so that maximum
performance is required to avoid impact.
The Airbus Industrie CFIT video program,
illustrating the terrain escape maneuver
techniques applicable to conventional aircraft and
protected aircraft, respectively.
The slope of the mountain should therefore be
adjustable up to at least 17 °, depending on the
climb gradients that can be achieved in the
escape maneuver.
Exercises to be incorporated in simulator training
sessions during transition training and/or
recurrent training.
•
Three typical exercises are described hereafter.
•
Additional briefing material to point out the risk
of CFIT during step-down non-precision
approaches and the advantages of using
a constant-angle stabilized profile.
To prevent negative training, the simulator must
realistically represent handling qualities and
performance as the speed reduces to stickshaker speed (or minimum speed, as applicable).
Simulator Exercises
All (E)GPWS
demonstrated.
Briefing Note 7.2 – Flying Constant-Angle Nonprovides
expanded
Precision
Approach
information on the benefits associated with
constant-angle non-precision approaches.
/
TAWS
modes
should
be
The objective should be to gain an understanding
of the parameters and limitations of the (E)GPWS /
TAWS installed on the aircraft type.
These exercises can be performed in either a fixedbase simulator (FBS) or a full-flight simulator (FFS).
Simulator Requirements for CFIT Prevention
Training
•
The capability should be provided to insert an
"electronic mountain" from the instructor panel at
a selected point ahead of the aircraft's present
position, on its projected flight path.
The following scenarios, to be performed in the FFS,
are designed to introduce CFIT awareness and to
demonstrate and practice the correct response to
(E)GPWS / TAWS warnings.
Terrain should be included in the database in the
vicinity of the airports selected for training.
The terrain database should extend over an area
of 25-30 NM radius centered on the airfield
reference point.
These scenarios may be modified in accordance with
the individual airline's training requirements or
operating environment.
This simulator visual system should be able to
display the terrain features.
Response to GPWS/TAWS – Pull-Up Maneuver Training
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Avoidance Maneuver in VMC
(E)GPWS / TAWS Warning in IMC
Objectives:
Objectives:
Demonstrate:
•
(E)GPWS / TAWS warnings and that response
must be immediate;
To re-inforce and confirm correct response to
(E)GPWS / TAWS in IMC, including pilot technique
and crew coordination.
•
Pilot pull-up technique (with special reference to
pitch force, as applicable, and pitch attitude); and,
Briefing:
•
Crew coordination aspects.
Although the trainees will know in advance that the
exercise is to be performed, explain that it is intended
to simulate an inadvertent descent below MSA due to
loss of situational awareness (e.g., because of
a lateral navigation error, an incorrect altitude
selection, an incorrect non-precision approach
procedure or any other factors).
Briefing:
Explain the objectives, point out that this is a training
exercise that is not intended to be a realistic
operational situation; describe the pull-up technique
required
for
the
particular
aircraft
type
( Figure 3 or Figure 4 and applicable FCOM and
QRH ).
Initial conditions:
Establish either one of the two following scenarios:
Initial conditions:
•
Establish initial approach configuration and speed,
at or near the maximum landing weight, in a shallow
descent or in level flight.
or
•
Procedure:
Insert an "electronic mountain" ahead of the aircraft,
talk to flight crew throughout the maneuver insisting
on an immediate and aggressive response.
Initial approach configuration and speed, at or
near the maximum landing weight, in a shallow
descent or in level flight (as in the first scenario).
Landing configuration, V APP, at or near
the maximum landing weight, on a typical
3-degree glide path.
Procedure:
Ensure proper crew coordination, with PNF calling
radio altitudes and trend (e.g. "300 ft decreasing").
Insert an "electronic mountain" ahead of the aircraft;
talk to flight crew throughout the maneuver insisting
on an immediate and aggressive response.
Continue maneuver at maximum performance until
mountain is cleared ( Figure 2 ).
Ensure proper crew coordination, with PNF calling
radio altitudes and trend (e.g. "300 ft decreasing...").
The duration of the maneuver should be long enough
for the pilot to demonstrate proficiency at maintaining
the maximum climb performance.
Continue maneuver at maximum performance until
terrain is cleared ( Figure 2 ); the maneuver should
be long enough for the pilot to demonstrate
proficiency at maintaining the maximum climb
performance.
Repeat the exercise,
proficiency is achieved.
as
needed,
until
crew
Repeat the exercise, as needed, up to proficiency.
Debriefing:
Debriefing:
Review the exercise, as appropriate.
Review the exercise, as appropriate.
Response to GPWS/TAWS – Pull-Up Maneuver Training
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Unexpected (E)GPWS / TAWS warning
Summary of key points
This scenario should be included in the LOFT session
that is normally programmed at the end of the
transition course, and also during recurrent training
LOFT sessions.
The following key points should be highlighted when
discussing CFIT awareness and response to a
(E)GPWS / TAWS warning:
•
Horizontal situational awareness and vertical
situational awareness must be maintained at all
times ( Figure 1 and Figure 2 );
•
Preventive actions must be (ideally) taken before
(E)GPWS / TAWS warning;
•
Response by PF must be immediate ( Figure 2 );
•
PNF must monitor and call the radio altitude and
its trend throughout the terrain avoidance
maneuver;
•
Pull-up maneuver must be continued at
maximum climb performance until warning has
ceased and terrain is cleared, as indicated by a
steadily increasing radio-altimeter reading
( Figure 2 ).
Objectives:
To maintain crew awareness of the CFIT hazard, and
to confirm crew proficiency in responding to
a (E)GPWS / TAWS warning.
Briefing:
None.
Initial conditions:
Establish either clean configuration or initial-approach
configuration and the associated maneuvering speed,
at maximum landing weight, in level flight or
descending.
Associated Briefing Notes
The following Briefing Notes should be reviewed
along with the above information to complete
the CFIT awareness and training program:
Procedure:
Clear the aircraft to descend to an altitude below
the MSA or provide radar vectors towards high
ground.
•
1.1 - Operating Philosophy - SOPs,
•
1.2 - Optimum Use of Automation,
If flight crew take corrective action before any
(E)GPWS / TAWS warning (as expected),
an "electronic mountain" can be inserted at a later
stage in the session at an appropriate time.
•
2.3 - Effective Crew/ATC Communications,
•
3.1 - Altimeter Setting – Use of Radio
Altimeter,
Verify the crew response to (E)GPWS / TAWS, and
the crew coordination during the avoidance
maneuver.
•
3.2 - Altitude deviations,
•
5.2 - Terrain Awareness,
•
7.1 - Flying Stabilized Approaches,
•
7.2 - Flying Constant-angle Non-precision
Approaches,
•
7.3 - Acquisition of Visual References,
•
7.4 - Flying Visual Approaches.
Debriefing:
Review the exercise, as appropriate.
Response to GPWS/TAWS – Pull-Up Maneuver Training
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Regulatory References
•
ICAO – Annex 6 – operation of Aircraft, Part I –
International Commercial Air Transport –
Aeroplanes, Appendix 2, 5.23.
•
FAR 91.223 – Terrain awareness and warning
system (TAWS).
•
FAR 121.354 - Terrain awareness and warning
system (TAWS).
•
FAR 121.360 – Ground proximity warning system
(GPWS) – Glide slope deviation alerting system.
Appendices - Figures
Figure 1
CFIT – An Encounter Avoided
Quito – Equador – March 92
Figure 2
CFIT – An Encounter Avoided
Quito – Equador – March 92
Crew response to RA Alert Light and GPWS Warning
Figure 3
Response to GPWS Warning
Conventional Aircraft Models
Figure 4
Response to GPWS Warning
Fly-by-wire Protected Aircraft Models
Figure 5
Response to GPWS Warning
( Typical Profiles )
Response to GPWS/TAWS – Pull-Up Maneuver Training
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QIT 115.3
VOR-DME
QUITO, ECUADOR
MARISCAL SUCRE INTL
VOR ILS RWY 35
LOC 110.5 IQO
QMS 115.0
VOR-DME
D 16.0 QIT
✳ 13,780 ft
D 16.0 QMS
Pull-up initiated
Projected impact 13,200 ft
✳
16,408 ft
Climbing to 17,000 ft
✳ 15,460 ft
•
ILS approach RWY 35 - Night time - IMC - Rain
•
QMS VOR-DME ( 115.0 ) tuned instead of QIT ( 115.3 )
•
Procedure turn flown with reference to QMS, hence 12 NM further south
•
Crew alerted by 2500-ft radio-altimeter light
•
Crew responded to GPWS MK II warning: Terrain - Terrain - Pull up ! Pull up !
•
GPWS warning remained activated during 40 seconds
•
High terrain was avoided by only 150 ft RA
Figure 1
CFIT – An Encounter Avoided
Quito – Equador – March 92
Drawing adapted from “ Flight Into Terrain And the Ground Proximity Warning System “ by Don Bateman
Response to GPWS/TAWS – Pull-Up Maneuver Training
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200 kt
4000 ft/mn
Terrain along track
Terrain if full procedure turn to right
17 degree pitch
Maximum thrust
Altitude ( ft MSL )
17 000
Flight path
MK II GPWS warning
Terrain-Terrain
Pull up ! Pull up !
16 000
16 DME QMS
( 28 DME QIT )
15 000
14 000
13 000
150 Radial QMS
( outbound )
2500 ft RA
Light
2500 ft RA
Light
12 000
150 ft RA
11 000
10 000
14
15
16
17
18
19
20
21
22
23
24
Distance from RWY 35 - NM
Figure 2
CFIT – An Encounter Avoided
Quito – Equador – March 92
Crew response to RA Alert Light and GPWS Warning
Drawing adapted from “ Flight Into Terrain And the Ground Proximity Warning System “ by Don Bateman
Response to GPWS/TAWS – Pull-Up Maneuver Training
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“ WHOOP WHOOP PULL UP “
Simultaneously :
−
PITCH ATTITUDE .................... AT LEAST 20° NOSE UP
Use stick shaker boundary as upper limit
−
THROTTLES ........................................ FULL FORWARD
−
A/THR ....................................................... DISCONNECT
−
AUTOPILOT .............................................. DISCONNECT
−
BANK ........................................................ WINGS LEVEL
−
SPEEDBRAKES ............................ CHECK RETRACTED
•
When flight path is safe and GPWS warning has ceased :
#
•
Decrease pitch attitude and accelerate
When speed above V LS ( as applicable ) and V/S positive :
#
Clean up aircraft as required
Figure 3
Response to GPWS Warning – Conventional Aircraft Models
!
“ WHOOP WHOOP PULL UP “ - “ TERRAIN TERRAIN
WHOOP WHOOP PULL UP “
Simultaneously :
−
AP ........................................................................... OFF
−
PITCH .............................................................. PULL UP
Pull up to full back stick and maintain
−
THRUST LEVERS................................................. TOGA
−
SPEEDBRAKES .......................... CHECK RETRACTED
−
BANK ....................................... WINGS LEVEL or adjust
•
When flight path is safe and GPWS warning has ceased :
#
•
Decrease pitch attitude and accelerate
When speed above V LS and V/S positive :
#
Clean up aircraft as required
Figure 4
Response to GPWS Warning – Fly-by-wire Protected Aircraft Models
Response to GPWS/TAWS – Pull-Up Maneuver Training
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A310 - 3-degree G/S - 30/40 - Gear down
Altitude ( ft )
5000
Max Landing Weight
4000
V LS + 5 kt
Sea Level
Stick shaker pitch attitude
3000
2000
3-degree / second
1000
up to 20-degree pitch attitude
0
0
1000
2000
3000
4000
5000
6000
7000
Distance ( m )
A319 - 3-degree G/S - CONF FULL - Gear down
Altitude ( ft )
5000
Max Landing Weight
4000
V LS + 5 kt
Sea Level
3000
2000
Pull up to full back stick
1000
0
0
1000
2000
3000
4000
5000
6000
Distance ( m )
Figure 5
Response to GPWS Warning
( Typical Profiles )
Response to GPWS/TAWS – Pull-Up Maneuver Training
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Approach-and-Landing Briefing Note
6.4 - Bounce Recovery – Rejected Landing
•
Introduction
A rejected landing (also referred to as an aborted
landing) is defined as a go-around maneuver initiated
after touchdown of the main landing gear or after
bouncing.
Loss of control following a go-around initiated
after thrust reverser selection (because of a
vehicle obstructing the runway) and failure of one
reverser to stow.
Touch-and-go ( training only )
Although a rare occurrence, a rejected landing is a
challenging maneuver decided and conducted in an
unanticipated and unprepared manner.
The objective of this Briefing Note is to define:
Although a touch-an-go is essentially a training
exercise, the conditions required for the safe conduct
of this maneuver provide a valuable introduction to the
discussion of rejected landings.
•
Preconditions:
•
Applicable decision criteria for:
−
Full-stop landing; or,
−
Rejected landing and go-around; and,
Four preconditions (usually referred to as the
“4-No rule”) must be observed prior to initiating
a touch-and-go:
Procedures and techniques for bounce recovery,
including:
−
Continued landing; or,
−
Rejected landing (i.e., go-around).
•
No ground spoilers:
− ground spoilers must not be armed or
manually selected after touchdown;
•
No autobrake:
−
Statistical data
•
No global statistical data are available on rejected
landing incidents or accidents but the following three
events illustrate the circumstances that may lead a
flight crew to reject the landing, and the possible
consequences of such a maneuver:
autobrake must not be armed;
No reverse:
− thrust reversers must not be selected upon
touchdown; and,
•
No pedal braking:
•
Tail strike following a go-around initiated due to
directional control difficulties after thrus t reverser
selection;
− pedal braking must not be used after
touchdown.
•
Climb performance limitation following the undue
selection
of
reverse
thrust
during
a
touch-and-go and failure of one reverser to stow;
and,
Performing a rejected landing in revenue service (i.e.,
with ground spoilers and autobrake armed, being
ready to select reverse thrust upon touchdown)
creates an added challenge.
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Aircraft reconfiguration:
Bouncing and bounce recovery
After touchdown for a planned touch-and-go,
the aircraft must be reconfigured to a takeoff
configuration:
Bouncing at landing usually is the result of one or
a combination of the following factors:
•
Loss of visual references;
•
Excessive sink rate;
Pitch trim reset within the takeoff trim setting
range;
•
Late flare initiation;
•
Incorrect flare technique;
•
Rudder trim reset (as applicable); and,
•
Excessive airspeed; and/or,
•
Throttle/thrust levers standup, as required (for
symmetrical engine acceleration).
•
Power-on touchdown (preventing the automatic
extension of ground spoilers, as applicable).
•
Flaps reset to a takeoff configuration;
•
The bounce recovery technique depends
the height reached during the bounce.
on
Task sharing:
Recovery from a light bounce (5 ft or less):
Performing a planned touch-and-go is a dynamic and
demanding maneuver in terms of task sharing:
•
The PF (trainee) is responsible for:
In case of a light bounced, the following typical
recovery technique can be applied:
− Tracking the runway centerline;
•
Maintain or regain a normal landing pitch attitude
(do not increase pitch attitude as this could
cause a tailstrike);
The PNF (instructor) is responsible for:
•
Continue the landing;
− Reconfiguring the aircraft for takeoff;
•
Use power as required to soften the second
touchdown; and,
•
Be aware of the increased landing distance.
− Advancing the throttle levers slightly above
idle.
•
− Resetting systems, as required;
− Monitoring engine parameters and flight modes
annunciations;
Recovery from a high bounce (more than 5 ft):
− Performing the takeoff callouts;
In case of a more severe bounce, do not attempt to
land, as the remaining runway length might not be
sufficient to stop the aircraft.
− Deciding to abort the takeoff, if required; and,
− Ensuring back-up of PF during rotation and
initial climb.
The following generic go-around technique can be
applied:
Perform ing a rejected landing (i.e., a non-anticipated
and non-prepared event) further amplifies the
importance for the PF and PNF to strictly adhere to
the defined task sharing and to concentrate on their
respective tasks.
•
Maintain or regain a normal landing pitch attitude;
•
Initiate a go-around by triggering go-around
levers/switches and advancing throttle levers to
the go-around thrust position;
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•
Be ready for a possible second touchdown;
•
Be alert to apply forward force on control column
(side stick) and reset the pitch trim nose down
as engines spool up (conventional aircraft models
only);
•
•
Commitment for Go-around
Maintain the landing flaps configuration or set the
required flaps configuration, as set forth in the
applicable FCOM;
If a rejected landing is initiated, the flight crew must
be committed to proceed with the go-around
maneuver and not retard the throttle levers in an
ultimate decision to complete the landing.
Reversing a go-around decision usually is observed
when the decision to reject the landing and to initiate
a go-around is taken by the first officer (as PF) but is
overridden by the captain.
When safely established in the go-around and no
risk of further touchdown exists (i.e., with a
steady positive rate of climb), follow normal goaround procedures; and,
Runway overruns, impact with obstructions and major
aircraft damage (or post impact fire) often are the
consequences of reversing an already initiated
rejected landing.
Reengage automation, as desired, to reduce
workload.
Summary of Key Points
The SOPs should define the respective decision
criteria for:
Commitment for Full-Stop Landing
Landing incidents and accidents clearly demonstrate
that after the thrust reversers have been deployed
(even at reverse idle), the landing must be completed
to a full stop, as a successful go-around may not be
possible.
•
•
Full-stop landing; or,
•
Rejected landing and go-around.
Procedures and techniques should be published for
bounce recovery, including:
The following occurrences have resulted in
a significantly reduced rate of climb or in departure
from controlled flight:
•
•
•
Continued landing; or,
•
Rejected landing (i.e., go-around).
Thrust asymmetry resulting from asymmetrical
engine spool up (i.e., asymmetrical engine
acceleration characteristics from a ground idle
level);
Associated Briefing Notes
Thrust asymmetry resulting from one thrust
reverser going to the stow position faster than the
other one; and,
•
6.1 - Being Prepared to Go-around,
•
7.1 - Flying Stabilized Approaches,
Severe thrust asymmetry resulting from one
thrust reverser failing to re-stow.
•
8.1 - Preventing Runway Excursions and
The following Briefing Notes can be reviewed in
association with the above information:
Overruns.
Bounce Recovery – Rejected Landing
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Chapter 7
Approach Techniques
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Approach-and-Landing Briefing Note
7.1 - Flying Stabilized Approaches
Introduction
Factor
Rushed and unstabilized approaches are the largest
contributory factor in CFIT and other approach-andlanding accidents.
High
Plan;
•
Prepare; and,
•
Execute a safe approach.
fast
approach
or
Rushed approaches result in insufficient time for the
flight crew to correctly:
•
and/or
% of Events
66 %
Low and/or slow approach
Flight-handling difficulties :
- demanding ATC clearances
45 %
- adverse wind conditions
This Briefing
discussion of:
Note
provides
an
overview
and
Table 1
•
Criteria defining a stabilized approach; and,
•
Factors involved in rushed and unstabilized
approaches.
Factors Involved
Note :
Factor
Flying stabilized approaches complying with the
stabilization criteria and approach gates defined
hereafter, does not preclude flying a Delayed Flaps
Approach (also called a Decelerated Approach) as
dictated by ATC requirements.
% of Events
Off-runway touchdown,
Tail strike,
75 %
Runway excursion or overrun
Statistical Data
Continuing an unstabilized approach is a causal
factor in 40 % of all approach-and-landing accidents.
Table 1 and Table 2 show the factors involved in
rushed and unstabilized approaches and the
consequences of continuing an unstabilized
approach.
CFIT
-- %
Loss of control
-- %
Table 2
Consequences of Continued Approach
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Approach Gates – Stabilization Heights
Defining a Stabilized Approach
The following approach gates and minimum
stabilization heights are recommended to achieve
timely stabilized approaches:
An approach is considered stabilized only if all the
following conditions are achieved before or when
reaching the applicable stabilization height:
For all types of approach:
Meteorological
Conditions
Height above
Airfield Elevation
IMC
1000 ft
VMC
500 ft
The aircraft is on the correct lateral and vertical flight
path
(based on navaids guidance or visual references)
Table 3
Only small changes in heading and pitch
are required to maintain this flight path
Minimum Stabilization Heights
The aircraft is in the desired landing configuration
The power is stabilized and the aircraft is trimmed to
maintain the target final approach speed
on the desired glide path
The landing checklist has been accomplished
as well as any required specific briefing
No flight parameter exceeds the criteria provided in
Table 6 and Table 7
Table 6 and Table 7 also define the criteria for
flight-parameters excessive-deviation callouts
Table 4
Note :
Non-normal conditions requiring deviation from the
above elements of a stabilized approach should be
briefed formally.
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For visual and circling approaches:
For all types of constant-angle approaches:
For visual approaches,
wings must be level on final
when the aircraft reaches
500 ft above airfield elevat ion
Parameter
Callout Criteria
Airspeed
Lower than V APP – 5 kt
For circling approaches,
wings must be level on final
when the aircraft reaches
300 ft above airfield elevation
or
Greater than V APP + 10 kt
(*)
Table 5
Excessive flight
callouts criteria
parameter
Vertical
Speed
deviation
Greater than – 1000 ft/mn
Note :
If the approach requires more than
– 1000 ft/mn
vertical speed
(e.g., for GS capture from above),
PF and PNF should discuss the
required vertical speed
When reaching the applicable stabilization height and
below, a callout should be performed by the PNF if
any flight parameter exceeds the limits provided in
Table 6 and Table 7.
(*):
The final approach speed V APP is considered to be
equal to V REF + 5 kt (or V LS + 5 kt, as applicable).
Pitch
Attitude
V REF is the reference target threshold speed in the
full flaps landing configuration (i.e., in the absence of
airspeed corrections because of wind, windshear or
non-normal configuration).
Lower than ( ** ) Nose Down
or
Greater than ( ** ) Nose Up
( ** ) :
Refer to the applicable SOPs for applicable pitch
attitude limits.
Bank
Angle
Greater than 7 degrees
Ground
Speed
Lower than V APP - 10 kt
( *** ) :
Monitoring the ground speed provides an awareness
of a possible impending wind shear.
( *** )
Maintaining the ground speed above V APP – 10 kt
provides an energy margin, in readiness for the
sudden head wind to tail wind shift usually
associated with wind shear.
Table 6
Maintaining a minimum ground speed is performed
automatically when flying in managed-speed on
fly-by-wire aircraft models.
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For LOC-only and ILS approaches:
In addition, a stabilized approach provides the
following benefits:
Parameter
Callout Criteria
LOC deviation
LOC-only approach : 1 dot
ILS CAT I : 1 dot
•
More time and attention are available for the
monitoring of ATC communications, weather
conditions, systems operation;
•
More time is available for effective monitoring and
back-up by the PNF;
•
Defined flight -parameter-deviation criteria and
minimum stabilization height support the
decision to land or go-around; and,
•
Landing performance is consistent with published
performance.
ILS CAT II / CAT III :
1/3 dot
or
Factors
Involved
Approaches
Excessive Deviation Warning
GS deviation
( ILS )
in
Unstabilized
The following circumstances, factors and errors are
often cited when discussing rushed and unstabilized
approaches:
1 dot
or
Excessive Deviation Warning
Table 7
•
Fatigue;
•
Pressure of flight schedule (i.e., making up for
takeoff delay);
•
Any
crew-induced
or
controller-induced
circumstances resulting in insufficient time to
plan, prepare and execute a safe approaches;
Benefits of a Stabilized Approach
This includes accepting requests from ATC for
flying higher and/or faster than desired or flying
shorter routings than desired;
Conducting a stabilized approach increases the flight
crew’ overall situational awareness:
•
Horizontal situational awareness, by closely
monitoring the flight path;
•
ATC instructions that result in flying too high
and/or too fast during the initial approach;
•
Speed awareness,
deviations;
•
•
Vertical situational awareness, by monitoring
the vertical flight path and the rate of descent;
Excessive altitude or excessive airspeed
(i.e., inadequate energy management) early in
the approach;
•
•
Energy awareness, by maintaining the engines
thrust to the level required to fly a 3-degree
approach path at the final approach speed (or at
the minimum ground speed, as applicable).
Late runway change (lack of ATC awareness of
the time required to reconfigure the aircraft
systems for a new approach);
•
Excessive
head-down
reprogramming);
by
monitoring
speed
This also enhances the go-around capability.
Flying Stabilized Approaches
Page 4
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(e.g.,
FMS
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•
Short outbound leg or short down-wind leg
(e.g., in case of unidentified traffic in the area);
•
Late takeover from automation (e.g., in case of
AP failing to capture the GS, usually due to crew
failure to arm the approach mode);
•
•
•
•
Steep approach (i.e., above desired flight path
with
excessive
vertical
speed
up
to
– 2200 ft/mn, flight path angle up to
15 % gradient / 9-degree slope);
Steep approaches appear to be twice as frequent
as shallow approaches;
Insufficient awareness of wind conditions:
− tailwind component;
•
Shallow approach (i.e., below desired glide path);
− low altitude wind shear;
•
− local
wind
gradient
and
turbulence
(e.g., caused by terrain or buildings); or,
Low airspeed maneuvering (i.e., inadequate
energy management);
•
Excessive bank angle when capturing the final
approach course (up to 40-degree);
•
Activation of a GPWS warning:
Incorrect anticipation of aircraft deceleration
characteristics in level flight or on a 3-degree
glideslope;
Failure to recognize deviations or to remember
the excessive-parameter-deviation criteria;
•
Belief that the aircraft will be stabilized at the
stabilization height or shortly thereafter;
•
Excessive confidence by the PNF that the PF
will achieve a timely stabilization;
•
PF/PNF over reliance on each other to call
excessive deviations or to call for a go-around;
and,
•
Full approach flown at idle down to touchdown,
because of excessive airspeed and/or altitude
early in the approach;
Premature or late descent due to absence of
positive FAF identification;
− recent weather along the final approach path
(e.g., downdraft caused by a descending cold
air mass following a rain shower);
•
•
in
-
Mode 2A : TERRAIN (not full flaps);
-
Mode 2B : TERRAIN (full flaps).
Late extension of flaps or flaps load relief system
activation (as applicable), resulting in the late
effective extension of flaps;
•
Flight-parameter excessive deviation
crossing the stabilization height:
Unstabilized
The following procedure deviations or flight path
excursions often are observed, alone or in
combination, in rushed and unstabilized approaches
(figures provided between brackets reflect extreme
deviations
observed
in
actual
unstabilized
approaches, worldwide).
Mode 1 : SINK RATE;
•
Visual illusions during the visual segment.
Deviations Observed
Approaches
-
•
-
Excessive airspeed (up to V REF + 70 kt);
-
Not aligned
difference);
-
Excessive bank angle (up to 40 -degrees);
-
Excessive vertical speed
(up to – 2000 ft/mn);
-
Excessive
glide
(up to 2 dots);
(up
to
20-degree
slope
heading
deviation
Excessive bank angle, excessive sink rate or
excessive
maneuvering
while
performing
a side-step;
Flying Stabilized Approaches
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•
Speedbrakes being still extended when in short
final (i.e., below 1000 ft above airfield elevation);
•
Excessive flight-parameter deviation(s) down to
runway threshold;
•
High runway-threshold crossing (up to 220 ft);
•
Long flare and extended touchdown.
Company’s Prevention Strategies
Personal Lines-of-defense
Detect:
Defined excessive-parameter-deviation criteria and a
defined stabilization height provide the PF and PNF
with a common reference for effective:
and
•
Monitoring (i.e., early detection of deviations);
and,
•
Back-up (i.e., timely and precise deviation
callouts for effective corrections).
To provide the time availability and attention required
for an effective monitoring and back-up, the following
should be avoided:
Company’s prevention strategies and personal linesof-defense to reduce the number of unstabilized
approaches should:
•
Late briefings;
•
Unnecessary radio calls (e.g., company calls);
•
Identify and minimize the factors involved;
•
Unnecessary actions (e.g., use of ACARS); and,
•
Provide recommendations for the early detection
and correction of unstabilized approaches.
•
Non-pertinent intra-cockpit conversations (i.e.,
breaking the sterile-cockpit rule).
The following four-step strategy is proposed:
•
Anticipate;
•
Detect;
Reducing the workload and cockpit distractions
and/or interruptions also provides the flight crew with
more alertness and availability to:
•
Correct; and,
•
Cope with fatigue;
•
Decide.
•
Comply with an unanticipated ATC request
(e.g., runway change or visual approach);
Anticipate:
•
Adapt to changing weather
approach hazards; and,
Some factors likely to result in a rushed and
unstabilized approach can be anticipated.
•
Manage a system malfunction (e.g., flaps
jamming or gear failing to extend or downlock).
Whenever practical, flight crews and controllers
should avoid situations that may result in rushed
approaches.
Correct:
The descent-and-approach briefing provides an
opportunity to identify and discuss factors such as :
Positive corrective actions should be taken before
deviations develop into a challenging or a hazardous
situation in which the only safe action is a go-around.
•
Non-standard altitude or speed restrictions
requiring a careful energy management :
conditions
or
Corrective actions may include:
An agreed strategy should be defined for the
management of the descent, deceleration and
stabilisation (i.e., following the concepts of next
targets and approach gate);
•
The timely use of speed brakes or the early
extension
of
landing
gear
to
correct
an excessive altitude or an excessive airspeed;
•
Extending the outbound leg or downwind leg.
This strategy will constitute a common objective
and reference for the PF and PNF.
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Decide:
Next Target and Approach Gate
An immediate go-around must be performed if:
Throughout the entire flight a next target should be
defined to stay ahead of the aircraft at all times.
•
•
The approach is not stabilized when reaching the
minimum stabilization height; or,
The defined next target should be any required
combination of:
Any flight parameter exceeds the related
excessive-deviation
criteria
(other
than
transiently)
when
below
the
minimum
stabilization height.
•
A position;
•
An altitude;
The following behaviors often are involved in the
continuation of an unstabilized approach:
•
A configuration;
•
•
A speed;
•
A vertical speed or flight path angle; and,
•
A power setting.
•
•
Confidence in a quick recovery (i.e., postponing
the go-around decision when parameters are
converging toward target values);
Overconfidence because of a long and dry
runway and/or a low gross-weight, although
airspeed and/or vertical speed are excessive;
During the approach and landing, the successive
next targets should be achieved for the approach to
be continued.
Inadequate readiness or lack of commitment to
conduct a go-around;
If the crew anticipates that one of the elements of the
next target will not be achieved, the required
corrective action(s) should be taken without delay.
A change of mindset should take place from:
•
•
−
“We will land unless …”; to,
−
“Let’s be prepared for a go-around and we will
land if the approach is stabilized and if we
have sufficient visual references to make a
safe approach and landing”.
The minimum stabilization height constitutes
a particular gate along the final approach;
a go-around must be initiated if:
•
Go-around envisaged but not initiated because
the approach was considered being compatible
with a safe landing; and,
The required configuration and speed is not
obtained or the flight path is not stabilized when
reaching the stabilization height;
or,
•
Absence of decision due to fatigue or workload
(i.e., failure to remember the applicable
excessive deviation criteria).
The aircraft becomes unstabilized below the
stabilization height.
Flying Stabilized Approaches
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•
Summary of Key Points
8.3 - Factors Affecting Landing
Distances.
Three essential parameters need to be stabilized for
a safe approach:
•
Aircraft track;
•
Flight path angle; and,
•
Airspeed.
Depending
equipment,
and visual
monitor the
on the type of approach and aircraft
the most appropriate level of automation
cues should be used to achieve and
stabilization of the aircraft.
When breaking-out of the cloud overcast and
transitioning to visual references, the pilot’s
perception of the runway and outside environment
should be kept constant by maintaining the:
•
Drift
correction,
to
continue
tracking
the runway centerline, resisting the tendency to
prematurely align the aircraft with the runway
centerline;
•
Aiming point (i.e., the touchdown zone),
to remain on the correct flight path until flare
height, resisting the tendency to move the aiming
point closer and, thus, descend below the
desired glide path (i.e., “duck-under”); and,
•
Final approach speed and ground speed, to
maintain the energy level.
Associated Briefing Notes
The following Briefing Notes can be reviewed in
association with the above information:
•
4.1 - Descent and Approach Profile
Management,
•
4.2 - Energy Management during
Approach,
•
6.1 - Being Prepared to Go-around,
•
7.2 - Flying Constant-angle Non-precision
Approaches,
•
8.2 - The Final Approach Speed,
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Regulatory references
•
ICAO – Annex 6 – Operations of Aircraft, Part I –
International Commercial Air transport –
Aeroplanes, Appendix 2, 5.18, 5.19.
•
ICAO – Procedures for Air navigation services –
Aircraft Operations (PANS -OPS, Doc 8168),
Volume I – Flight Procedures (particularly, Part IX
- Chapter 1 - Stabilized Approach – Parameters,
Elements of a Stabilized Approach and Goaround Policy).
•
ICAO – Preparation of an Operations Manual
(Doc 9376).
•
FAA Document 8430.6A – Air Carrier Operation
Inspector Handbook – Chapter 7 – paragraph
951.d.(4).(f): procedures for altitude and vertical
speed monitoring.
•
FAA Document 8400.10, stating that a sink rate
of greater than approximately 1000 ft/mn is
unacceptable below 1000 ft above airfield
elevation.
Other References
•
U.S. National Transportation Safety Board
(NTSB) – Report NTSB-AAS-76-5 –.Special
Study: Flight Crew Coordination Procedure in Air
Carrier Instrument Landing System Approach
Accidents.
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Approach-and-Landing Briefing Note
7.2 - Flying Constant-Angle Non-Precision Approaches
Introduction
Statistical Data
Planning and conducting a non-precision approach
(NPA) is certainly the most challenging and
demanding part of a flight, this includes:
Almost 60 % of CFIT incidents and accidents occur
during step-down non-precision approaches.
•
Decision making on strategies and options;
•
Effective task-sharing;
•
Crew coordination (monitoring and callouts);
and,
The
constant-angle
non-precision
approach
(CANPA) technique, described in this Briefing Note,
should be implemented and trained worldwide for
preventing CFIT and other approach-and-landing
accidents.
•
CFIT awareness (response
EGPWS / TAWS warning).
to
GPWS
Defining Non-Precision Approaches
or
A non-precision approach is an instrument approach
that does not incorporate vertical guidance
(i.e., not using a glide slope beam).
Various types of NPAs (also called non-ILS
approaches) share common features but also
involve specific techniques, depending on the
navaid being used or on the strategy being adopted
for:
The navaid being used is therefore primarily used
for lateral guidance.
•
Lateral and vertical guidance;
Non-precision instrument approaches include the
use of the following navaids:
•
Descending from the final approach fix (FAF)
down to the minimum descent altitude(height)
MDA(H); and,
•
•
Making the decision before or when reaching
the MDA(H).
NDB, VOR, LOC-only, VOR-DME, LOC-DME,
LOC BCK CRS.
Note 1:
The LDA
(Simplified
approaches
procedures
approaches.
This Briefing Note describes the features common
to all types of non-precision approaches and
the specific features of each individual type of
approach.
(LOC-type Directional Aid), SDF
Directional Facility) and Circling
share most of the features and
applicable to other non-precision
Note 2:
This Briefing Note highlights the technique of
constant-angle
(constant-slope)
non-precision
approach, as opposed to the traditional step-down
technique.
GPS approaches performed in overlay to a
conventional
non-precision
approach
and
RNAV/RNP approaches, with or without GPS
PRIMARY, also share most of the strategies and
procedures described in this Briefing Note.
Flying Constant-Angle Non-Precision Approaches
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Instrument approaches usually consist of three
approach segments:
•
Initial approach :
−
−
•
Notes :
The charted MDA(H) is referenced to the touchdown
zone elevation (TDZE), to the runway (RWY) or the
airport reference point (APT or ARP).
From an initial approach fix (IAF) to the
intermediate fix (IF), if defined;
The ICAO PANS-OPS define the MDA(H) as a
function of the obstacle clearance altitude (height)
[OCA(H)]:
Minimum obstacle clearance: 1000 ft;
Intermediate approach :
MDA(H) = OCA(H) + 30 ft
−
From the IF to the final approach fix (FAF);
−
Minimum obstacle clearance: 500ft; and,
VDP Concept
•
Final approach:
−
From the FAF to the MDA(H) and visual
descent/decision point (VDP) or MAP;
−
Minimum obstacle clearance: 250 ft.
The Visual Descent/Decision Point (VDP) is a point
in the approach, at the MDA(H), where the aircraft is
approximately on a 3-degree glide path, as
illustrated by Figure 2.
For non-precision approaches, the intermediate
approach is a transition segment during which the
aircraft is configured for the final approach:
Decision at VDP :
- Descent from VDP
✠
•
Landing gear extended;
•
Landing flaps configuration established;
•
Speed stabilized on the final approach speed;
•
Aircraft aligned with the final approach course;
and,
•
Landing checklist and briefings completed.
or
- Go-around
V
M
VDP
MAP
MDA(H)
FAF ( or FDF )
Figure 2
Visual Descent Point ( VDP ) Concept
Decision
Limit
✠
The VDP location is defined by:
Go-Around
V
M
•
MDA(H)
Distance from a VOR-DME or LOC-DME;
or,
FAF ( or FDF )
MAP
•
Time from the FAF.
The VDP should be considered as the last point
from which a stabilized visual descent to the runway
can be conducted.
Figure 1
Step-down Final Approach
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Constant-Angle
Final
Strategies and Options
Planning a non-precision or RNAV (aRea
NAVigation) approach requires defining strategies
and options for:
Step-down approaches are based solely on an
obstacle-clearance profile; step-down approaches
are not optimized for modern commercial jetliners.
•
Lateral guidance :
− use of selected modes (selected heading
mode and localizer mode); or,
Flying a constant-angle approach profile:
•
Provides a more stabilized flight path;
•
Reduces the workload during this critical flight
phase; and,
•
Eliminates the risk of error in step-down
distances / altitudes and the need for a level-off
at the MDA(H).
− use of selected modes (altitude hold mode
and V/S mode); or,
This reduces the risk of CFIT.
− use of FMS vertical navigation down to the
FAF (or beyond, as applicable, in accordance
with the FCOM).
− use of FMS lateral navigation (NAV mode),
until LOC interception or down to MDA(H).
•
•
Vertical guidance :
Final descent from FAF (or final descent fix):
− use of a step-down descent with level off at
MDA(H); or,
✠
− use of a continuous constant-angle descent
with decision before or when reaching
MDA(H).
Decision
Go-Around
V
M
MDA(H)
Notes :
FAF ( or FDF )
VDP
The requirement to make the decision before
or when reaching the MDA(H) – i.e. the
allowance to descend below the MDA(H)
during the go-around maneuver (dip thru) –
depends upon the applicable operational
regulation.
MAP
Figure 3
Constant-angle Final Approach
On a constant-angle non-precision approach,
the MDA(H) may be considered as a DA(H)
only if the approach has been surveyed and
approved by the state navigation agency
and/or operational authorities.
•
Use of inertial flight path vector (as available),
with or without the autopilot (AP) engaged.
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A non-precision approach may be conducted using
either:
•
Continuing the approach below the MDA(H) is
permitted only if at least one of the visual references
is distinctly visible and identifiable by the PF (refer to
Briefing Note 7.3 - Acquisition of Visual
References).
Lateral navigation guidance, with monitoring of
raw data;
or,
•
Raw data only;
The landing following a non-precision approach is
a visual and manual landing.
Raw data supported by the use of the flight path
vector (as available).
Standard Operating Procedures
or,
•
The importance of task sharing, standard calls and
altitude callouts or parameter excessive-deviation
callouts must be emphasized.
A non-precision approach may be conducted with
the AP engaged:
•
•
Using FMS guidance with:
Refer also to the following Briefing Notes:
−
lateral navigation until LOC interception or
down to the MDA(H); and,
−
vertical navigation down to the FAF (or
beyond, as applicable in accordance with
the FCOM), then using vertical speed mode
down to the MDA(H); or,
should
1.1 – Operating Philosophy - SOPs,
•
1.4 - Standard Calls.
The following overview outlines the actions and
standard calls required by SOPs and illustrates the
typical phases of the approach and the sequence of
decisions involved in a non-precision approach:
Using selected guidance: heading mode and
altitude hold or vertical speed modes, after
leaving the IAF and down to the MDA(H).
The autothrottle/autothrust system
engaged, in the speed mode.
•
Descent / Approach Preparation:
be
CFIT Awareness
During the final descent to the MDA(H), PF and
PNF should monitor the vertical flight path and
lateral flight path, and should not descend to the
next step-down altitude before reaching the
associated descent fix (DME distance or other
reference).
•
Anticipate and confirm the runway in use and
the type of approach to be conducted.
•
Define the
guidance:
−
approach
strategy
for
lateral
Use of selected heading mode and navaid
raw data;
or,
−
In IMC or at night, flight crews should respond
immediately to any GPWS or EGPWS / TAWS
warning.
Descending Below MDA
Use of FMS lateral navigation (NAV mode)
with monitoring of raw data, if :
!
the approach is defined in the FMS
navigation database; and,
!
the FMS navigation accuracy meets the
criteria for approach;
(typically, better than 2 Nm in terminal
area and better than 1 Nm for
approach).
During a non-precision approach the PF is engaged
in either handflying the aircraft or supervising the AP
operation, the PNF is in charge of acquiring and
announcing the visual references.
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•
vertical
•
Use of altitude hold and vertical speed
mode;
Confirm the timing from the FAF to the MAP (or
to the VDP) or confirm the DME distance
defining the VDP and/or MAP;
•
Confirm the navaids set-up
courses, and identification);
•
Compute the expected ground speed;
•
Confirm the published vertical speed for the final
descent segment or compute the target vertical
speed, based on the published approach glide
path and anticipated ground speed; and,
•
Confirm the use of the FD or of the flight path
vector (as applicable).
Define the
guidance:
−
Getting to Grips with
Approach-and-Landing Accidents Reduction
approach
strategy for
or,
−
•
Use of FMS vertical navigation mode, down
to the FAF (or beyond, as applicable, in
accordance with the FCOM);
Insert the desired runway, type of approach and
STAR (from the database) in the FMS flight
plan;
•
Enter the descent and surface winds on the
appropriate FMS page, as applicable;
•
Enter the landing configuration and wind
correction on the appropriate FMS page, as
applicable;
•
If the use of the vertical navigation mode is
authorized after the FAF, enter the MDA(H) on
the appropriate FMS page;
•
Set-up navaids (identify, as required); and,
•
Plan the descent for reaching the IAF at the
prescribed altitude and planned airspeed.
(frequencies,
During Descent:
•
Check FMS navigation accuracy:
−
Check that the FMS bearing/distance to a
tuned VOR-DME and the RMI (ND) raw
data agree within the criteria defined in the
SOPs and confirm strategies for lateral and
vertical guidance (i.e., FMS or selected
guidance).
Before reaching the IAF / Holding fix:
Approach Briefing:
For a detailed overview of the approach briefing,
refer to the Briefing Note 1.6 – Approach and
Go-around briefing.
•
Review terrain features, obstacles position and
other obstacle clearance awareness items;
•
Confirm the arrival minimum safe altitude
(MSA);
•
Review the approach procedure (fixes, altitude
constraints and speed restrictions, required
navaids, etc);
•
Review the approach vertical profile (step-down
altitudes) and MDA (H);
•
Set/check the MDA (H) on the baro altimeter
bug;
•
Review the expected visual
(approach and runway lighting);
•
•
Keep the AP engaged with FMS or selected
modes for lateral navigation and vertical
navigation, as desired;
•
Keep both navigation displays (NDs) in MAP
mode (unless the FMS navigation accuracy is
greater than 1 Nm);
•
If FMS lateral navigation mode is used:
Check the FMS navigation accuracy level
(e.g., R/I or HIGH or […], depending on the
FMS type and standard);
−
Check ND for correct flight plan and for
correct TO WPT;
−
Confirm the FMS NAV mode engagement
on FMA; and,
•
Adjust the descent rate for reaching the IAF at
the charted/prescribed altitude and planned
airspeed;
•
Establish the desired configuration and speed:
references
Review the missed-approach procedure;
−
−
Clean configuration or slats extended; and,
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−
Adjust the weather radar gain and tilt, as
applicable, for optimum use of radar capability
(for weather avoidance and/or enhanced
horizontal situational awareness).
Different procedures may apply depending
on whether the desired ILS-DME is in the
FMS database or not.
Upon reaching the IAF or Holding fix:
•
If FMS lateral navigation mode will be used
beyond the IAF or holding fix, keep both NDs in
MAP mode;
•
If selected heading or localizer mode will be
used to capture and track the final approach
course:
−
For a LOC or LOC- DME approach, set the
final approach course on the ILS course
selector and arm the localizer mode,
•
Set the PF ND to ARC mode or ROSE
mode:
Check and confirm the correct sequencing
of the FMS flight plan:
−
The TO WPT should be the FAF;
−
If a TO WPT other than the FAF is
displayed on the ND, perform a DIR TO
[FAF].
Note :
Ensuring the correct sequencing of the FMS
flight plan is essential to be able
to re-engage the NAV mode in case of
go-around,
The PNF may keep the ND in MAP mode
for situational awareness (i.e., with display
of speed and altitude constraints).
During the holding pattern or when suitable:
Configure the aircraft:
Before reaching the FAF (or the Final Descent
Point, if different):
−
Slats extended only or approach flaps; and,
•
−
Associated maneuvering speed.
Align the aircraft (within 5 degree) with the final
approach course;
•
Select the landing gear down;
Exiting the holding pattern:
•
Arm the ground spoilers;
•
•
Set landing flaps;
•
Set and establish the final approach speed;
•
Set the GA altitude (if the GA altitude is the
same as the FAF crossing altitude, set the GA
altitude only after initiating the final descent);
•
Perform the LANDING checklist;
•
For an NDB approach, set the final
approach course on the ILS course selector,
this will set the ILS course pointer on the ND
and provide a course reference,
If use of FMS vertical navigation is not
authorized beyond the FAF, deselect the FMS
vertical navigation mode by selecting the altitude
hold or the vertical speed mode, as required;
•
For a VOR or VOR-DME approach, set the
final approach course on the VOR course
selector but do not arm the VOR mode,
If V/S mode will be used after the FAF, set the
published or computed vertical speed and
course; and/or,
•
If flight path vector (FPV, as available) will be
used after the FAF set the published or
computed flight path angle (FPA) and track.
•
Select the holding EXIT prompt; in order to allow
the correct sequencing of the FMS flight plan.
Leaving the holding pattern:
•
If FMS lateral navigation mode is not used, use
the selected heading mode (or the track mode as available) to intercept the final approach
course, as follows:
−
−
Capture and track the VOR course using
the selected heading or track mode.
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Approaching the FAF or the Final Descent Fix
(FDF)
At MDA(H) / reaching the VDP :
•
Typically 0.3 nm to 0.2 nm before reaching the FAF
/ FDF (i.e., to begin the descent at the FAF / FDF,
on an accurate profile):
•
Engage the V/S mode and check V/S mode
engagement on FMA;
•
Set the published (or computed) vertical speed,
as a function of the ground speed;
•
Select FPV (as applicable);
•
Start timing (as required); and,
•
Crosscheck and announce the next fix (or DME
distance, as applicable) and crossing altitude.
−
•
•
Check and announce the altitude deviation
from charted crossing altitude;
−
Adjust the vertical speed, as required; and,
−
Call out the next fix (or DME distance) and
the associated crossing altitude.
−
Initiate a go-around; and,
−
Overfly the MAP to ensure adequate
obstacle clearance and fly the published
missed-approach procedure (or follow ATC
instructions).
•
Use of incorrect
approach charts;
•
Late aircraft descent preparation;
•
FMS navigation accuracy not checked;
•
FMS flight plan not correctly setup;
•
Navaids not correctly
identification or course);
•
Incomplete briefing;
•
Incorrect choice of autopilot modes;
•
Incorrect entry of autopilot or autothrottle
targets;
•
Inadequate monitoring of raw data;
•
Absence of cross-check and/or ineffective backup by PF and PNF;
or
outdated
tuned
instrument
(frequency,
Set or confirm the go-around altitude on FCU.
At
MDA(H)
+
1/10
rate
(i.e., MDA(H) + 50 to 100 ft) :
•
If adequate visual references are not acquired :
Training feedback and return on in-service
experience indicate that the following adverse
factors and errors are involved frequently in nonprecision approaches:
Monitor the vertical speed, flight path vector (as
available), course, distances, altitudes and call
out the published vertical profile at each safety
altitude / distance check:
−
Disconnect the AP and continue the
approach visually (the autothrottle/autothrust
should remain engaged in speed mode
down to the retard point, as applicable).
Factors in Non-Precision Approaches
During the descent towards the MDA(H):
•
If adequate visual references are acquired :
of
descent
If the approach has not been surveyed and/or
if the operational authorities do not accept the
MDA(H) as a DA(H), anticipate the go-around
decision to prevent undershooting the MDA (H).
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•
Inaccurate tracking of final approach course
when using the selected heading (or track)
mode;
•
Late aircraft configuration;
•
Final approach speed not stabilized at FAF;
•
Failure to account for prevailing head wind
component when computing the vertical speed
target for the final constant-angle descent
segment;
•
Incorrect identification of FAF (or final descent
fix);
•
Go-around altitude not timely set;
•
Premature descent below the next step-down
altitude (if multiple step-downs) or below the
MDA(H); and,
•
•
Beginning the final descent at the exact final
descent fix;
•
Maintaining the correct flight path angle (and or
vertical speed) during the final descent
segment;
•
Acquiring and announcing visual references;
•
Calling the decision to land or go-around;
•
Not descending below the MDA(H) before
reaching the VDP;
•
Being prepared and minded to go-around.
Associated Briefing Notes
The following Briefing Notes provide expanded
information to supplement the above discussion:
Absence of identification or timing (as relevant)
of the VDP or MAP.
•
1.1 - Standard Operating Procedures,
•
1.4 - Standard Calls,
Summary of Key Points
•
The successful preparation and conduct of a nonprecision approach should include the following key
points:
4.2 - Energy Management During
Approach,
•
7.1 - Flying Stabilized Approaches,
•
7.3 - Acquisition of Visual References.
•
Determining the type of guidance to be used;
•
Preparing the FMS, as applicable;
•
Completing a descent-and-approach briefing;
•
Planning aircraft configuration setup;
•
Monitoring the descent profile;
•
Managing
the
aircraft
energy
intermediate and final approach;
during
•
Not descending below an altitude
reaching the next step-down fix;
before
•
Determining the correct flight path angle (and/or
vertical speed) for the final descent segment;
Regulatory References
•
ICAO – Procedures for Air navigation Services –
Aircraft Operations (PANS-OPS, Doc 8168),
Volume I – Flight Procedures.
•
ICAO – Manual of All Weather Operations (Doc
9365).
•
FAA Special
(11/26/99).
Flying Constant-Angle Non-Precision Approaches
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Approach-and-Landing Briefing Note
7.3 - Acquisition of Visual References
•
Introduction
The transition from instrument references to visual
references is an important element of any type of
instrument approach.
Some variations exist in airline
philosophies about task sharing for:
•
Acquisition of visual references;
•
Conduct of landing; and,
•
Conduct of go-around.
operating
−
This task sharing provides an alternative
definition of the CAPT and F/O functions
during the approach;
−
This operating philosophy usually is referred
to as Shared approach or Monitored
approach or Delegated handling approach.
The lack of acquisition adequate visual references
or the loss of visual references is a frequent causal
factor in approach-and-landing accident; this
includes:
PF-PNF task sharing:
−
−
Statistical data
Two operating philosophies are commonly used for
task sharing during approach:
•
CAPT-F/O task sharing:
The task sharing for the acquisition of visual
references depends on:
!
the type of approach (i.e., on the time
available for the acquisition of visual
references); and,
!
the use of automation (i.e., on the level
of automation and redundancy);
The Airbus Industrie operating philosophy
and training philosophy promote a PF-PNF
task sharing with acquisition of visual
references by:
!
PNF, for non-precision and CAT I ILS
approaches; and,
!
PF, for CAT II / CAT III ILS approaches.
•
Descending below the MDA(H) or DA(H) without
adequate visual references or having acquired
incorrect visual references (e.g., a lighted area
in the airport vicinity, a taxiway or an other
runway);
•
Continuing the approach after the loss of visual
references (e.g., because of a fast moving
rainshower or fog patch).
CFIT awareness
During the final descent, PF and PNF should
monitor the vertical flight path and lateral flight path,
and should not descend below the charted minimum
safe altitude before reaching the next descent fix
(i.e., a DME distance, locator or other reference).
For CAT II / CAT III operations, the
CAPT usually is the PF and only an
automatic approach and landing is
considered.
In IMC or at night, PF should respond immediately
to any GPWS warning or EGPWS / TAWS warning.
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When using external references, the available visual
cues must allow the pilot to assess the pitch attitude
and bank angle, the lateral position and heading, the
horizontal flight path (track) and vertical flight path
(flight path angle).
Defining Visual References
When a low visibility approach is anticipated,
the approach briefing should include a thorough
review of the approach light system (ALS) using the
instrument approach chart and the airport chart.
After adequate visual references have been
acquired, to allow descending below the MDA(H) or
below the DA(H), the different elements of the
approach light system provide visual cues for:
Depending on the type of approach and prevailing
ceiling and visibility conditions, the lighting
element(s) expected to be available at the first
visual contact should be discussed.
Continuing the approach below the MDA(H) or
DA(H) is permitted only if at least one of the
following visual references is distinctly visible and
identifiable (as detailed in the operator’s applicable
regulation):
•
•
Assessing the aircraft position, drift angle and
distance to the touchdown zone; and,
•
Perceiving any rate of change during the final
phase of the approach.
Acquisition of Visual References
The approach light system (ALS):
−
•
e.g., sequenced flashing lights, steady
runway alignment lights, 1000 ft or 500 ft
cross bars;
The task sharing for acquisition of visual references
and for monitoring the flight path and aircraft
systems varies depending on :
The [runway] threshold;
•
The type of approach (i.e., criticality of time
available for acquiring the visual references);
and,
•
The level of automation being used :
The threshold markings; or,
The threshold lights;
•
The runway end identification lights ( REIL );
− hand flying ( using FD );
•
The visual approach slope indicator ( VASI or
PAPI );
or,
•
− AP engaged (i.e. AP monitoring - single AP or
dual AP approach).
The touchdown zone;
The touchdown zone markings;
The formal announcement of visual references
should be limited to the runway or runway/airport
environment (although announcing the view of the
ground may be considered).
The touchdown zone lights; or,
•
The runway;
The runway markings;
Non-precision and CAT I ILS approaches :
The runway edges or centerline lights.
Non-precision approaches and CAT I ILS
approaches can be flown manually following the FD
orders or instruments raw data or with AP engaged.
Acquiring adequate visual references requires that
the visual cues have been in view for sufficient time
for the pilot to make an assessment that the landing
can be completed without further reference to the
aircraft guidance-systems.
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The PF is engaged directly in either:
•
In CAT III weather conditions, automatic landing
usually is mandatory.
Hand-flying the airplane and following the FD
orders while monitoring instruments and navaids
raw data,
Consequently, the terms “visual references” do not
have the same meaning for CAT II and CAT III
approaches.
or,
•
Supervising the autopilot operation, being ready
to take over if required.
For CAT II approaches, having visual references
means being able to see to land (i.e., being able to
land manually).
The PNF therefore is responsible for progressively
acquiring and announcing the visual references
while monitoring the flight progress and backing-up
the PF.
For CAT III approaches, having visual references
means being able to see to verify the aircraft
position.
The PNF scans alternatively inside and outside,
announces
flight-parameter
deviations
and
announces:
The U.S. FAR 91.189 and the European JAR-OPS
1.430 account for this interpretation in defining the
minimum visual cues that must be available at the
DA(RA DH).
•
“Visual“ (or whatever visual reference is in
sight), if adequate visual references are
available; or,
“One hundred above” then “Minimum“ (if no
radio-altimeter autocallout is available), if
adequate visual references are not available.
For CAT III with No DH, no visual cue is specified
but it is a recommended practice for the PF to look
for visual references before touchdown; these visual
cues are later used for monitoring the AP guidance
during the rollout phase.
Note :
The PNF should not lean forward while attempting
to acquire visual references.
During an automatic approach and landing, the flight
path is fully monitored by the AP (autoland warning),
and supervised by the PNF (excessive deviation
callouts).
•
If the PNF calls “Visual” while leaning forward,
the PF might not have visual references yet,
because of his/her different viewing angle (cockpit
cutoff angle).
The PF can concentrate his/her attention on the
acquisition of visual references; progressively
increasing his/her external scanning as the DH is
approached.
The PF confirms the acquisition of visual references
and announces “ Landing “ ( or “ Go Around “,
if visual references are not adequate ).
When an approach is conducted close to the
minimums, the time available for making the
transition from instrument references to visual
references is extremely short; the PF must therefore
dedicate his/her primary attention to the acquisition
of visual references.
For landing, the PF progressively transitions from
instrument flying to external visual references.
The PNF must maintain instrument references
throughout the approach and landing (or go-around)
to:
CAT II / CAT III ILS approaches :
CAT II / CAT III ILS approaches are flown making
use of the automatic landing system.
CAT II automatic approaches can be followed by
a manual landing (although the standard operating
procedure is to use the autoland capability).
•
Monitor the flight path and the instruments; and,
•
Be ready to call any flight-parameter excessivedeviation or warning.
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Implementation
Shared Approach / Monitored Approach /
Delegated Handling Approach
The implementation of the Shared approach /
Monitored approach / Delegated handling approach
concept requires the development of specific SOPs
and standard calls.
Description :
The Shared approach or Monitored approach or
Delegated handling approach provides an
alternative definition of the PF and PNF functions,
based on a CAPT-F/O task sharing.
The sequence of planned or conditional actions and
callouts should be thoroughly and accurately briefed
during the approach briefing.
This task sharing can be summarized as follows:
•
This sequence of actions and callouts usually
include the following:
Regardless of who was the PF for the sector,
the F/O is always the PF for the approach;
•
The CAPT is PNF and monitors the approach
and the acquisition of the visual references;
•
When reaching the DA(H) or before, depending
on the operator’s policy for CAT II / CAT III:
For the CAPT:
•
If visual references are acquired before or at
DA(H):
− Call Landing; and,
− Takeover controls (i.e., control wheel / side
stick and throttle/thrust levers) and call I have
control or My controls, as per company
SOPs;
− The F/O – PF calls Minimum;
− If visual references are acquired, the CAPT
calls Landing, takes over the controls
(i.e., flight controls and throttle levers) and
conduct the landing;
•
If visual references are not acquired at DA(H):
− Call Go-around, monitor and backup the F/O
during the go-around initiation and missedapproach.
− If visual references are not acquired, the
CAPT calls Go-around and the F/O initiates
the go-around and flies the missed-approach.
For the F/O:
•
Whatever the decision, Landing or Go-around,
the F/O maintains instrument references for
the complete approach and landing (or go-around
and missed-approach).
− Call You have control or Your controls, as per
company’s SOPs;
− Continue monitoring instrument references;
Depending on the F/O experience, the above roles
can be reversed.
•
•
Depending on the airline’s operating philosophy, this
concept is applicable to:
•
If CAPT calls Go-around:
− Initiate immediately the go-around and fly the
missed-approach;
This task sharing eliminates the transition from
instrument flying to visual flying (and, in case of a
go-around, from semi-visual references back to
instrument flying) but involves a changeover of
controls at a late stage in the approach.
•
If CAPT calls Landing:
If CAPT does not make any call or does not
takeover controls and throttle levers
(possible subtle incapacitation):
− Call “Go-around/Flaps” and initiate an
immediate go-around.
CAT II / CAT III approaches only (for all other
approaches the PF is also the pilot-landing); or,
The change of controls at a late stage of the
approach requires precise callouts and action
gestures to prevent any misunderstanding and/or
delayed action.
All types of approaches (except automatic
landings where the Captain resumes control
earlier, typically from 1000 ft RA to 200 ft RA).
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Applicable callouts and actions should be recalled
by the flight crew during the CAT II / CAT III briefing.
Low below glide path:
A shallow approach with high thrust, when being too
low, may result in a floating flare and a long landing.
Standard Operating Procedures
The crew should maintain level flight until the
correct flight path is established.
The importance of task sharing and standards
callouts during the final phase of the approach
should be emphasized.
Lateral offset :
Standard calls for confirming the acquisition of
visual references vary from airline to airline.
Determine an aiming point on the extended runway
centerline, approximately half the distance to
the touchdown point and aim towards this point
while maintaining the correct glide path, airspeed
and thrust.
Visual or [acquired visual reference] usually is used
if adequate visual references are available and if the
aircraft is correctly aligned and on the approach
glide path, otherwise the callout Visual or [acquired
visual reference] is followed by an assessment of
the lateral deviation or vertical deviation (offset).
To prevent overshooting the runway centerline,
anticipate the alignment by beginning the final turn
shortly before crossing the extended inner runway
edge line.
The PF (CAPT) determines whether the lateral
deviation or vertical deviation (offset position) can
be safely corrected and announces Continue (or
Landing) or Go-around.
Loss Of Visual References below MDA(H)
or DA(H)
Recovery from Offset Position
If loss of adequate visual references occurs when
below the MDA(H) or DA(H), an immediate goaround must be initiated.
Recovery from a lateral deviation or vertical
deviation (offset position) when going visual requires
careful control of the pitch attitude, bank angle and
power with reference to instruments to prevent crew
spatial disorientation by visual illusions.
The U.S. FAR 91.175 and 121.189 state that each
pilot […] shall immediately execute an
appropriate missed-approach procedure […]
whenever [the conditions for operating below the
authorized MDA [or DH] are not met.
The
PNF
is
responsible
for
monitoring
the instruments and for calling any excessive
parameter-deviation from established criteria.
Summary of key points
Vertical deviation :
During non-precision approaches and CAT I ILS
approaches, both the PF and PNF must acquire
the same – and correct – visual references.
High above glide path:
The use of a high sink rate with low thrust, when
being too high, may result in landing short of the
runway or in a hard landing.
During CAT II / CAT III ILS approaches and all
shared approaches, the F/O must remain headdown
to monitor flight instruments during the complete
approach and landing (and go-around).
The crew should establish the correct flight path, not
exceeding the maximum permissible sink rate
(usually 1000 ft/mn).
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Associated Briefing Notes
Other References
The following Briefing Notes can be reviewed to
amplify and complement the above information:
•
•
1.1 - Operating Philosophy - SOPs,
•
1.2 - Optimum Use of Automation,
•
1.4 - Standard Calls,
•
5.3 - Visual Illusions Awareness.
U.S. National Transportation Safety Board
(NTSB) – Special Report NTSB-AAS-76-5 –
Special Study: Flight Crew Coordination
Procedure in Air Carrier Instrument Landing
System Approach Accidents.
Regulatory references
•
ICAO – Annex 6 – Operations of Aircraft - Part I
– International Commercial Air Transport –
Aeroplanes, 4.2.7, 4.4.1.
•
ICAO – Manual of All-Weather Operations
(Doc 9365).
•
FAR 91.175 – Takeoff and landing under IFR –
requirement for immediate go-around in case of
loss of visual references when below MDA(H) or
DA(H) during a non-precision approach or a
CAT I ILS approach.
•
FAR 91.189 – Takeoff and landing under IFR –
requirement for immediate go-around in case of
loss of visual references when below DA(H) or
RA DH during a CAT II or a CAT III ILS
approach.
•
FAR
121.567
–
Instrument
approach
procedures and IFR landing minimum.
•
AC 91-25A related to the loss of adequate
visual references.
•
FAA AC 120-29 and 120-28D related to
autoland and CAT II / CAT III approaches.
•
JAR-OPS 1.430, Appendix 1 to JAR-OPS
1.430, AMC OPS 1.430(b)(4) and IEM to
Appendix 1 to JAR-OPS 1.430 – Definition of
required visual references for various types and
categories of approaches.
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Approach-and-Landing Briefing Note
7.4 - Flying Visual Approaches
Introduction
Statistical data
Accepting an ATC request for a visual approach or
requesting a visual an approach should be evaluated
carefully against the following decision criteria:
Visual Approaches account for:
•
Ceiling and visibility conditions;
•
Darkness (or twilight);
•
Weather activity:
•
30 % of all approach-and-landing accidents;
•
40 % of fatal accidents.
Visual approaches at night present a greater risk
exposure because of fewer visual cues and
a greater potential for visual illusions and spatial
disorientation.
− wind, turbulence;
•
− rain showers; and/or,
Defining a visual approach
− fog or smoke patches;
The JAR-OPS 1, the U.S. FAA Aeronautical
Information Manual (AIM) and the ICAO provide
different definitions for visual approaches.
Crew experience
environment:
with
airport
and
airport
The U.S. FAA AIM definition is proposed as
reference for this Briefing Note:
− surrounding terrain; and/or,
− specific
airport
(obstructions, …);
•
and
runway
•
[A visual approach is] an approach conducted on
an instrument flight rules (IFR) flight plan which
authorizes the pilot to proceed visually and clear
of clouds to the airport;
•
The pilot must, at all times, have either the
airport or the preceding aircraft in sight;
•
The visual approach must be authorized and
under the control of the appropriate air traffic
control facility; and,
•
Reported weather at the airport must be ceiling at
or above 1000 ft and visibility 3 miles or greater.
hazards
Runway visual aids:
− Type of approach lighting system; and,
− Availability of a VASI or PAPI.
This Briefing Note provides an overview and
discussion of the operational factors involved in the
preparation, conduct and monitoring of a visual
approach.
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Flying a visual approach at night
Terrain awareness:
Hazards associated with visual approaches and
landings at night must be fully understood.
When selecting or accepting a visual approach
at night, flight crew should be aware of
the surrounding terrain features and man-made
obstacles.
A visual approach at night should be considered only
if:
•
Weather is suitable for flight under VFR;
•
A visual pattern or a published VISUAL approach
chart is available and used;
•
A pattern altitude is defined; and,
•
Flight crew is familiar with airport hazards and
obstructions (this includes the availability of
active NOTAMs).
In darkness, an unlighted hillside between a lighted
area and the runway threshold may prevent the flight
crew from correctly perceiving the rising terrain.
Objective:
The objective of a visual approach is to conduct an
approach:
At night, when an instrument approach is available
(particularly an ILS approach) an instrument
approach should be preferred to a visual approach, to
reduce the risk of accidents caused by visual
illusions.
•
Using visual references;
•
Being stabilized by 500 ft above airfield elevation
(or per company SOPs):
- on a nominal 3-degree glide path;
- in the landing configuration;
Visual illusions (e.g., black-hole effect) affect the
flight crew vertical and horizontal situational
awareness, particularly during the base leg and when
turning final.
- at the final approach speed; and,
- with aircraft and crew ready for landing.
If the aircraft is not stabilized at 500 ft above airfield
elevation or if the approach becomes unstable when
below 500 ft above airfield elevation, a go-around
must be initiated.
If a precision approach is not available, selecting an
approach supported by a VASI or PAPI
(as available) should be the preferred option.
Visual Approach Overview
Use of automated systems:
The following overview provides a generic description
of the various phases and techniques involved in a
visual approaches.
The use of automated systems (autopilot, flight
director, autothrottle/autothrust) should be adapted to
the type of visual approach (published approach or
pattern) and to the ATC environment (planned
navigation or radar vectors).
References:
Visual approaches
reference to either:
should
be
performed
with
•
A published VISUAL approach chart for the
intended runway; or,
•
The visual approach circuit pattern (altitude,
configuration and speed schedule) published in
the FCOM or QRH.
During the final phase of the approach, it is
recommended to disconnect the autopilot, clear the
flight director bars, keep the autothrottle/autothrust
engaged in speed mode (at pilot’s discretion) and
select the flight path vector symbol (as available).
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Initial / intermediate approach:
Base leg:
The FMS may be used to build the teardrop outbound
leg or the downwind leg, for enhanced horizontal
situational awareness. Nevertheless, this should be
planned
and
prepared
when
setting
the FMS before reaching the top-of-descent.
Resist the tendency to fly a continuous closing-in
turn towards the runway threshold.
Before turning final (depending on the distance to the
runway threshold), extend landing flaps and begin
reducing speed to the final approach speed.
As applicable, setup navaids for the instrument
approach associated with the landing runway
(for monitoring and in case of loss of visual
references).
Estimate the glide path angle to the runway threshold
based
on
available
visual
cues
(e.g., VASI) or navaids data (ILS glide slope or
altitude/distance from touchdown zone, based on a
typical 300-ft/nautical mile glide path).
Brief (or rebrief) the key points of the visual approach
and rebrief also the key points of the associated
instrument approach.
Note : GS deviation and VASI information are
reliable only when within 30 degree from
the final approach course.
Review and discuss the published missed-approach
procedure (if different from the IFR missed approach
procedure).
corresponding
Do not exceed 30-degree bank angle when tuning
final.
Barometric-altimeter bug and radio-altimeter DH may
be set (as per company’s SOPs) for enhanced terrain
awareness.
Anticipate the crosswind effect (as applicable) in
order to complete the turn being correctly established
on the extended runway centerline with the required
drift correction.
Outbound leg or Downwind leg:
Final approach:
In order to be lined-up on the final approach course
and stabilized at 500 ft above airfield elevation,
intercept the final approach course at typically 3 nm
from the runway threshold (time the outbound leg or
downwind leg accordingly, as a function of the
prevailing airspeed and wind component).
Aim at being fully aligned (i.e., with wings level) and
stabilized at the final approach speed by 500 ft above
airfield elevation (or per company SOPs).
Extend slats and
maneuvering speed.
fly
at
the
Monitor ground speed variations (for windshear
awareness) and perform altitude callouts and
excessive-parameter-deviation callouts as for an
instrument approach.
Maintain typically 1500 ft above airfield elevation
(or the charted altitude) until starting the final descent
segment or turning base leg.
Maintain visual scanning toward the aiming point
(typically, 1000 ft from the runway threshold) to avoid
any tendency to inadvertently descend (“duck-under”)
below the final approach glide path (use the GS
deviation index or the VASI / PAPI, as available, for
crosscheck).
Configure the aircraft as per the SOPs or circuit
pattern, typically aiming at turning base leg with
approach flaps, landing gear down and ground
spoilers armed.
Do not exceed 30-degree bank angle when turning
into base leg.
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Factors Affecting Visual Approaches
Typical Deviations in Visual Approaches
The following factors often are involved in rushed and
unstabilized visual approaches:
The following observations are typical of rushed or
unstabilized visual approaches:
•
Pressure of flight schedule (adopting shortcuts in
an attempt to make up for delay);
•
Steep approach (i.e., high
excessive rate of descent);
•
Crew-induced or ATC-induced circumstances
resulting in insufficient time or distance to plan
and execute the approach;
•
Shallow approach (i.e., below desired glide path);
•
GPWS activation :
•
Excessive altitude or airspeed (i.e., inadequate
energy management) early in the approach;
•
Too short downwind leg (circuit pattern), too short
outbound leg (teardrop pattern) or too close
interception (direct base leg interception);
•
Lack of awareness of tail wind and/or crosswind
component or failure to account for prevailing
wind component;
•
Incorrect anticipation of aircraft deceleration
characteristics in level flight or on a 3-degree
glide path;
•
Failure to recognize deviations or to remember
the excessive-parameter-deviation criteria;
•
Belief that the aircraft will be stabilized at the
stabilization height or shortly thereafter;
•
PNF excessive confidence in the PF in achieving
a timely stabilization or reluctance to challenge
the PF;
•
fast,
with
-
Mode 1 : SINK RATE;
-
Mode 2A : TERRAIN (less than full flaps);
-
Mode 2B : TERRAIN (full flaps);
•
Final-approach-course interception too close to
the runway threshold because of an insufficient
outbound teardrop leg or downwind leg;
•
Laterally unstable final approach due to lack of
crosswind awareness and correction;
•
Excessive bank angle and maneuvering to
capture the extended runway centerline
(overshoot) or to perform a side-step maneuver;
•
Unstabilized approach with late or no go-around
decision; and,
•
Inadvertently descending below (“ducking-under”)
the 3-degree glide path.
Summary of Key Points
The following key points should be discussed during
flight crews training for enhancing safe visual
approaches:
PF and PNF excessive reliance on each other to
call excessive deviations or to call for
a go-around;
•
Visual illusions (e.g., black hole, runway slope,
off-airport light patterns such as brightly lighted
parking lots or streets);
•
Inadvertent (unconscious) modification of the
aircraft trajectory to maintain a constant
perception of visual references; and,
•
and
Loss of ground, airport or runway vi sual
references, with both PF and PNF looking
outside to reacquire visual references.
•
Assessing the company or personal exposure
(i.e., operating environment);
•
Developing company prevention strategies and
personal lines-of-defense;
•
Weighing the time saved against the possible
risk;
•
Awareness of and accounting for all weather
factors;
•
Awareness of surrounding terrain and obstacles;
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•
Awareness of airport environment, airport and
runway hazards (i.e., black hole effect);
•
Use of a published visual approach chart or visual
circuit pattern;
•
Tuning and monitoring all available navaids;
•
Optimum use of automation with timely reversion
to hand flying;
•
Adherence to defined PF/PNF task sharing:
•
5.3 - Visual Illusions Awareness,
•
7.1 - Flying Stabilized Approaches.
− PF should fly and look outside (i.e., being
head up), while,
− PNF should monitor instruments (i.e., being
head down);
•
Maintaining visual contact with runway and other
traffic at all times; and,
•
Performing altitude callouts and excessiveparameters-deviation callouts, as for instrument
approaches; and,
•
Complying with associated go-around policy.
Associated Briefing Notes
The following Briefing Notes provide expanded
information on operational aspects and techniques
involved in visual approaches:
•
1.1 - Operating Philosophy - SOPs,
•
1.2 - Optimum Use of Automation,
•
1.3 - Operations Golden Rules,
•
1.4 - Standard Calls,
•
1.5 - Normal Checklists,
•
1.6 - Approach and Go-around Briefings,
•
3.1 - Altimeter Setting – Use of Radio
Altimeter,
•
4.2 - Energy Management during
Approach,
•
5.2 - Terrain ( CFIT ) Awareness,
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Regulatory References
•
ICAO – Annex 4 – Chapter 12 – Visual Approach
Charts.
•
FAA – AC 60-A – Pilot’s Spatial Disorientation.
•
FAA – AIM – Pilot/Controller Glossary.
•
FAR 91.175 – Takeoff and landing under IFR –
Loss of visual references.
•
JAR-OPS 1 – Subpart E – 1.435 (a) (8) – Visual
approach.
Flying Visual Approaches
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Chapter 8
Landing Techniques
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Approach-and-Landing Briefing Note
8.1 - Preventing Runway Excursions and Overruns
Introduction
Runway excursions and runway overruns may occur
following all types of approaches:
Runway excursions include the following types of
events:
•
Visual;
•
•
Non-precision; or,
•
Precision approaches.
Veering off the runway during the landing roll;
or,
•
Veering off the runway or taxiway when vacating
the runway.
Runway excursions and overruns are observed
regardless of daytime or nighttime conditions.
Runway overruns define events where the aircraft
rollout extends beyond the end of the landing
runway.
Runway excursions and overruns often are
associated with one or several of the following
weather conditions:
This Briefing Note provides an overview of the
factors involved in runway excursions and runway
overruns, and suggests the development of
corresponding prevention strategies and lines-ofdefense.
•
Low visibility or fog;
•
Heavy rain (i.e., runway contaminated with
standing water or runway slippery-when-wet);
•
Cold
weather
operation
(i.e.,
contaminated with slush or ice); and,
•
Steady or gusting crosswind or tail wind
component.
Statistical Data
Runway excursions and overruns account for
typically 20 % of all approach-and-landing
accidents.
Event
runway
Runway excursion or overrun events also have
been experienced with good weather and dry
runway conditions.
% of Events
Runway excursion
8%
Factors Involved in Runway Excursions
Runway overrun
12 %
Runway excursions often are the result of the
following operational factors and circumstances:
Table 1
Weather factors:
Runway Excursions and Overruns
Landing overruns represent 80 % of all observed
runway overrun events (i.e., including runway
overruns following a rejected takeoff).
•
Runway condition (wet or contaminated by
standing water, slush, snow or ice);
•
Wind shear;
Preventing Runway Excursions and Overruns
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•
Cross-wind component;
•
Inaccurate information on wind and/or runway
conditions; and,
•
Reverse-thrust effect in crosswind and on
contaminated runway.
Performance factors:
•
Crew technique or decision factors:
•
Incorrect
crosswind
landing
techniques
(e.g., drifting during the decrab and align phase,
absence of decrab when landing in high
crosswind conditions);
•
Inappropriate differential braking by crew;
•
Use of nose-wheel-steering tiller at high speed;
and,
•
•
•
Unanticipated runway condition (i.e., worse than
anticipated);
shear
or
tail
Unstable approach path (steep and fast):
− Excessive height over threshold (up to 220 ft)
resulting in a long landing;
Weather factors:
wind
braking capability (e.g., anti-skid);
− Landing fast (up to V APP + 40 kt at runway
threshold); and/or,
The following operational factors and circumstances
are observed as recurring patterns, alone or in
combination, in runway-overrun events:
Unanticipated
component.
−
Inoperative brake(s) not accounted for per
MEL/DDG provision.
•
Absence of
warranted;
•
Captain (PNF)’s decision to land following
intention or initiation of go-around by first officer
(PF);
•
Long flare ( allowing the aircraft to float to bleed
an excess-speed uses three times more runway
than decelerating on the ground );
•
Failure to arm
associated with
inoperative);
•
Power-on touchdown (i.e., preventing automatic
extension of ground spoilers);
•
Failure to detect the non-deployment of ground
spoilers (e.g., absence of related standard call);
•
Forward
throttle/thrust
levers
movement
resulting in the premature retraction of ground
spoilers and in the loss of autobrake;
Uncommanded differential braking.
•
lift dumping (e.g., ground spoilers);or,
Crew technique or decision factors:
Asymmetric thrust (i.e., forward thrust on one
side, reverse thrust on opposite side); or,
Inaccurate surface wind information; and,
−
•
Vacating the runway at an excessive speed.
•
aircraft configuration (e.g., slats, flaps or roll
spoilers);
Incorrect assessment of landing distance for
prevailing wind and runway conditions; and,
Factors Involved in Runway Overruns
•
−
•
Systems factors:
•
Incorrect assessment of landing distance
following an in-flight malfunction or an MEL
condition affecting:
wind
Preventing Runway Excursions and Overruns
Page 2
go-around
ground
thrust
decision,
when
spoilers (usually
reversers being
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•
Bouncing and incorrect bounce recovery;
Standard operating procedures (SOPs):
•
Late braking (or late takeover from autobrake
system, when required); and,
•
•
Reduced braking efficiency while assuring
directional control in crosswind conditions.
Define criteria and callouts for stabilized
approach and define minimum stabilization
heights (approach gates) depending on weather
conditions (i.e., IMC versus VMC);
•
Define task sharing and standard calls for final
approach and rollout phases; and,
•
Incorporate a crew callout for runway length
remaining (e.g., xyz ft(m) runway remaining or
xyw ft(m) to go), in low visibility conditions,
based on:
Systems factors:
•
Loss of pedal braking; or,
•
Antiskid malfunction resulting in aquaplaning (as
evidenced by extensive spots on all affected
tires).
− runway-lighting color change;
− runway-distance-remaining
available); and/or,
Prevention Strategies and Lines-of-Defense
markers
(as
− other available visual cues (such as runway
or taxiway intersections).
The following prevention strategies and lines-ofdefense should be implemented to address the
factors involved in runway excursions and overruns:
Performance data:
Policies:
•
•
Define policy and procedures to promote the
readiness and commitment to go-around if the
conditions for a safe landing are not achieved.
(i.e., discouraging any attempt to rescue what is
likely to be an hazardous landing);
•
•
•
•
•
Define policy to ensure that inoperative brakes
(“cold brakes”) are reported in the aircraft
logbook and accounted for in accordance with
the MEL;
Publish landing distances for various:
−
type of braking (i.e., pedal braking or
autobrake); and,
−
runway conditions; and,
Provide flight crews with landing distance
corrections for runways featuring
−
downhill slope; and/or,
−
high elevation.
Crew techniques:
Define policy and procedures for rejected
landing (i.e., bounce recovery);
•
Define policy and procedures prohibiting landing
beyond the published touchdown point (zone);
and,
Publish procedures and provide training for
crosswind landing technique (i.e., crabbed
approach with wings-level);
•
Publish procedures and provide training for
decrab technique, depending on crosswind
component and runway condition (i.e., complete
decrab, partial decrab or absence of decrab);
•
Publish procedures for optimum use of
autobrake system and thrust reversers on
contaminated runway;
Define policy encouraging a firm touchdown
when operating on a runway contaminated with
standing water or slush.
Preventing Runway Excursions and Overruns
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Summary of key points
Provide recommendations for the use of rudder,
differential braking, nosewheel steering for
directional control, depending on the speed and
runway condition; and,
Runway excursions and runway overruns can be
categorized into six families of events, depending on
their primary causal factor:
Publish specific recommendations for aircraft
lateral and directional control after crosswind
landing.
•
Events resulting from an unstabilized approach;
•
Event resulting
technique;
•
Events resulting from unanticipated or moresevere-than-expected
adverse
weather
conditions;
•
Events resulting from reduced or loss of lift
dumping or braking efficiency;
•
Events
resulting
from
configuration, including:
from
an
incorrect
flare
Crew awareness:
•
Ensure
flight
crews
awareness
and
understanding of all factors affecting landing
distances;
•
Ensure
flight
crews
awareness
and
understanding of conditions conducive to
hydroplaning;
an
abnormal
•
Ensure
flight
crews
awareness
and
understanding of crosswind and wheel cornering
issues;
•
Ensure flight crews awareness of windshear
hazards and develop corresponding procedures
and techniques (with special emphasis on
monitoring ground speed variations during
approach);
•
Develop flight crews awareness of relationships
among
braking
action,
runway friction
coefficient,
runway-condition
index,
and
maximum recommended crosswind component
depending on runway condition; and,
Corresponding company prevention strategies and
individual lines-of-defense can be developed for
each family through:
•
•
Ensure flight crews awareness of runway
lighting changes when approaching the runway
end, e.g.:
-
Centerline lighting
lighting only):
•
-
(standard
Runway edges lighting (HIRL only):
•
aircraft dispatch under minimum equipment
list [MEL] / dispatch deviation guide [DDG];
or,
−
in-flight malfunction; and,
Events resulting from incorrect crew action and
coordination, under adverse technical or
weather conditions.
•
Strict adherence to SOPs;
•
Enhanced awareness of environmental factors;
•
Enhanced
understanding
of
aircraft
performance and handling techniques; and,
•
Enhanced alertness for:
centerline
white lights changing to alternating red
and white lights between 3000 ft and
1000 ft from runway end, and to red
lights for the last 1000 ft; and,
−
−
flight-parameters monitoring:
−
excessive-deviation callouts; and,
−
mutual cross-check and back-up.
White lights changing to yellow lights on
the last 2000 ft of the runway.
Preventing Runway Excursions and Overruns
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Associated Briefing Notes
The following specific Briefing Notes provide
expanded information to supplement the above
overview:
•
1.1 - Operating Philosophy - SOPs,
•
1.4 - Standard Calls,
•
6.4 - Bouncing Recovery – Rejected
Landing,
•
7.1 - Flying Stabilized Approaches,
•
8.2 - The Final Approach Speed,
•
8.3 - Factors Affecting Landing
Distances,
•
8.4 - Optimum Use of Braking Devices,
•
8.5 - Operation on Wet or Contaminated
Runway,
•
8.6 - About Wind Information,
•
8.7 - Crosswind Landing.
Preventing Runway Excursions and Overruns
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Approach-and-Landing Briefing Note
8.2 - The Final Approach Speed
Assuring a safe landing requires achieving
a balanced distribution of safety margins between:
The final approach speed computation is the result
of a tactical choice performed by the flight crew to
assure the safest approach and landing for the
prevailing conditions in terms of:
•
The computed final approach speed; and,
•
Gross weight;
•
The resulting landing distance.
•
Wind conditions;
•
Flaps configuration (when several
configuration are certified for landing);
Introduction
This Briefing Note provides an overview of:
flaps
•
The definition of the final approach speed;
•
•
Aircraft configuration (speed corrections for
abnormal configurations);
Factors affecting the computation of this target
speed; and,
•
Icing conditions;
•
Use of A/THR in SPD mode; or,
•
Autoland.
•
Rule applied for the combination of speed
corrections.
The final approach speed V APP can be computed
based on the reference threshold speed V REF or on
the minimum selectable speed V LS (as available).
Statistical Data
The assessment of the final approach speed rarely
is a factor in approach-and-landing incidents and
accidents (even in runway overrun events), but
approaching at a speed significantly faster than the
computed target speed often is cited as a causal
factor.
V REF is defined as:
( )
V REF = 1.X * x (stall speed with full landing flaps* )
V LS is defined as:
Defining the Final Approach Speed
V LS = 1.X * x (stall speed in actual configuration* )
The final approach speed is the speed to be
maintained down to 50 ft over the runway threshold.
( * ) 1.3 and minimum stall speed ( V S MIN )
on conventional aircraft models; or,
( )
1.23 and stall speed under 1g ( V S 1g )
on fly-by-wire aircraft models.
The Final Approach Speed
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The final approach speed V APP can be determined
based on V REF or V LS, as follows:
Factors Affecting the Final Approach Speed
The speed corrections on V REF account for:
The following speed corrections should are not be
added, only the highest speed correction should be
considered (unless otherwise stated in the
applicable FCOM and QRH):
•
Aircraft configuration ( CONF CORR ):
•
Wind correction;
−
landing with less than full flaps; or,
•
Speed correction for ice accretion;
−
abnormal configuration;
•
Speed correction for the use of the A/THR in
SPD mode or for autoland;
•
Speed correction for forecast downburst / wind
shear conditions.
V APP = V REF + Corrections
•
Operational factors:
−
WIND CORR for wind component, gusty
crosswind or suspected wind shear; and,
−
+ 5 kt for use of A/THR in SPD mode or if
significant ice accretion is suspected.
The FCOM and QRH provide the rules applicable
for the aircraft type and model.
Gross weight:
or,
Because V REF is referenced to the stall speed
(V S MIN or V S 1g), V REF depends on the gross
weight.
V APP = V LS + Increments + Corrections
The speed increments on V LS account for:
•
The FCOM and QRH provide V REF tables for
normal landings and overweight landings.
Configuration conditions that are not included in
the computation of the V LS.
Wind conditions:
The speed corrections on V LS account for:
•
The wind correction on the final approach speed
provides an additional margin relative to the stall
speed, to cope with speed excursions caused by
turbulence and wind gradient.
Operational factors only:
−
WIND CORR for wind component, gusty
crosswind or suspected wind shear; and,
−
+ 5 kt for use of A/THR in SPD mode or
if significant ice accretion is suspected.
Airbus Industrie uses the following wind corrections
(WIND CORR):
•
A320/A330/A340 series:
−
(the speed correction for ice accretion is
+ 5 kt or + 10 kt, depending on aircraft
model).
•
A310/A300-600:
−
The resulting final approach speed V APP provides
the best compromise between handling qualities
(stall margin and/or maneuverability / controllability)
and landing distance.
•
For clarity and commonality among various Airbus
models, the following overview and discussion
refers only to the computation of V APP based on
V REF.
1/3 of the headwind component (excluding
the gust), limited to 15 kt;
(1/3 of the tower average wind) or (the gust
increment), whichever is higher, limited to
15 kt; or,
A300B2/B4 and A300 FFCC:
−
A graphical assessment based on the tower
wind velocity and wind angle, limited to
15 kt.
The Final Approach Speed
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No wind correction is applied for tailwinds.
Use of A/THR in SPD mode:
On some aircraft models, the WIND CORR can be
entered on the appropriate FMS page.
When using the A/THR in SPD mode during the
final approach, a 5-kt speed correction on V REF
should be added to account for the accuracy of the
autothrottle/autothrust system in maintaining the
final approach target speed.
Flaps configuration:
When several flap configurations are certified for
landing, the reference threshold speed (for the
selected configuration) is defined as:
This speed correction ensures that a speed equal to
or greater than V REF ( V LS ) is maintained at all
times down to 50 ft over the runway threshold.
V REF full flaps + ∆V REF.
CAT II / CAT III autoland:
In calm-wind conditions, in light-and-variable wind
conditions and in light turbulence conditions,
V REF + 5 kt is a typical target threshold speed.
For CAT II approaches using the A/THR in SPD
mode, CAT III approaches and autoland
approaches (regardless of weather conditions),
the 5-kt speed correction on V REF is required by
certification.
Abnormal configuration:
System malfunctions (such as the loss of one
hydraulic system or the jamming of either slats or
flaps) require a speed correction to restore:
•
The stall margin (e.g., loss or jamming of slats
and/or flaps); or,
•
The controllability / maneuverability (e.g., loss of
part of roll spoilers, V MCL limitation if
applicable).
Ice accretion:
When severe icing conditions are encountered,
a 5-kt or 10-kt speed correction must be considered
to account for the accretion of ice on the unheated
surfaces of the aircraft.
Downburst / Windshear:
The speed corrections provided in the FCOM and
QRH take into account all the consequential effects
associated
with
the
primary
malfunction
(i.e. no combination of speed corrections is
required, unless otherwise stated and explained).
The following rules are used to
the different types of speed corrections:
Downburst / windshear
anticipated based on;
conditions
may
be
•
Pilot’s reports from preceding aircraft;
•
Alerts issued by the airport low level windshear
alert system (LLWAS); or,
•
Data from a terminal Doppler weather radar
(TDWR).
combine
•
When two malfunctions affect the stall margin,
both speed corrections are added;
•
When two malfunctions affect the controllability /
maneuverability , only the higher speed
correction is considered;
When downburst / windshear conditions are
anticipated the landing should be delayed or the
aircraft should divert to the destination alternate
airport.
•
When one malfunction affects the stall margin
and the other one affects the controllability /
maneuverability, then only the higher speed
correction is considered.
If delayed landing or diversion is possible, a speed
correction (usually up to 15 kt to 20 kt, based on the
anticipated windshear) is recommended.
These rules are provided herein for enhanced
understanding purposes only.
Landing with less than full flaps is recommended
to maximize the climb gradient capability; the final
approach speed should be adjusted accordingly.
The Final Approach Speed
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Microbursts or other types of wind shear usually are
characterized by a significant increase of the head
wind component preceding a sudden shift to a tail
wind component.
The CONF CORR and WIND CORR are combined
according to the following rules (or as directed by
FCOM and QRH):
When wind shear is anticipated the ground speed
should be monitored closely for enhanced wind
shear awareness.
•
If the CONF CORR is equal to or greater than
20 kt, no WIND CORR is applied;
•
If the CONF CORR is lower than 20 kt, then the
CONF CORR + WIND CORR is limited to
20 kt.
To ensure an adequate energy margin, a minimum
ground speed should be maintained at all times.
The 5-kt speed correction for the use of
autothrottle/autothrust and the 5-kt or 10-kt speed
correction for ice accretion (as applicable) may be
disregarded if the other speed corrections exceed
5 kt.
This minimum-ground-speed technique (known as
GS mini) is implemented as follows:
•
Conventional aircraft models:
−
•
By adjusting manually the thrust to maintain
the GS not below V APP – 10 kt;
The above strategies allow distributing and
balancing the safety margins between the landing
speed and the landing distance.
Fly-by-wire aircraft models:
−
By selecting managed speed.
When and How To Combine
Increments and Corrections ?
Note :
Speed configuration corrections for autoland are not
discussed in this Briefing Note because in case of
system malfunction requiring a CONF CORR,
autoland usually is not permitted.
Speed
The different speed corrections are added or not in
order to equally distribute the safety margins related
to the following objectives:
Summary of key points
•
Stall margin;
•
Controllability / maneuverability; and,
The data and rules provided in the FCOM and QRH
allow achieving a balanced distribution of safety
margins between:
•
Landing distance.
•
The computed final approach speed; and,
•
The resulting landing distance.
In case of system malfunction(s) resulting in a
configuration correction (CONF CORR) on V REF,
the final approach speed becomes equal to:
The applicable FCOM and QRH provide speed
increments, speed corrections and rules for each
individual aircraft model.
V REF + CONF CORR + WIND CORR
The WIND CORR is limited to 15 kt.
The CONF CORR is determined by referring to
the FCOM or QRH.
The Final Approach Speed
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Associated Briefing Notes
The following related Briefing Notes supplement the
above discussion information:
•
7.1 - Flying Stabilized Approaches,
•
5.4 – Wind Shear Awareness,
•
8.1 - Preventing Runway Excursions and
Overruns,
•
8.3 - Factors Affecting Landing
Distances,
•
8.4 - Optimum Use of Braking Devices.
Regulatory References
•
FAA AC 120-29 – Criteria For Approval of
Category I and Category II Landing Weather
Mimima for FAR 121 Operators.
•
FAA AC 120-28D – Criteria For Approval of
Category III Weather Mimima for Takeoff,
Landing and Rollout.
The Final Approach Speed
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Approach-and-Landing Briefing Note
8.3 - Factors Affecting Landing Distance
Required Landing Distance - JAA / FAA
Introduction
Runway overruns are involved in 12 % of approachand-landing accidents.
Dry runway
Wet runway
Understanding the factors affecting landing distance
can contribute to reducing the number of runwayoverrun events.
Actual Landing
Regulatory
Distance ( dry )
Factor = 1.67
50 ft at threshold
This Briefing Note is supplemented by the Briefing
Notes 8.2 – The Final Approach Speed and
8.4 - Optimum Use of Braking Devices .
+15%
If wet
Required runway length (dry) = Actual landing distance (dry) x
1.67
Defining the Landing Distance
Required runway length (wet) = Actual landing distance (dry) x
When
referring
to
the
landing
two definitions must be considered:
•
distance,
Figure 1
The actual landing distance achieved to land
and come to a complete stop (on a dry runway)
after crossing the runway threshold at 50 ft.
Required Landing Distance - UK CAA
The actual landing distance is used as reference
for any in-flight assessment of the landing
distance.
•
Dry or
Wet runway
The required landing distance is obtained by
applying a regulatory factor to the actual landing
distance.
The required landing distance is used for
dispatch purposes (i.e., for selecting the
destination, alternate and diversion airports).
Actual landing distances are demonstrated during
certification flight tests without the use of thrust
reversers.
Actual landing
Regulatory
Distance ( dry )
Factor = 1.92
50 ft at threshold
Required runway length (dry or wet) = Actual landing distance (dry) x
1.92
Figure 1 and Figure 2 illustrate the actual and
required landing distances, as defined by
the European JAA / U.S. FAA and by the U.K. CAA.
Figure 2
Factors Affecting Landing Distance
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Factors Affecting Landing Distance
Runway profile (sl ope):
The actual landing distance is affected by various
operational factors; thus reducing the regulatory
margins, this includes:
All Airbus aircraft models are certified for landing
operation on runways not exceeding a mean downhill
slope of 2%.
•
Airfield elevation or low
(i.e., increased ground speed);
QNH
condition
•
Runway profile (i.e., downhill slope);
The applicable operational regulation (JAR-OPS)
requires to account for the runway slope only when
the downhill slope exceeds 2%.
•
Runway condition (i.e., nature and depth of
contaminant; wet runway
or runway
contaminated by standing water, slush, snow or
ice);
Therefore, the landing distance tables published in
the FCOM and QRH are applicable without correction
within the certified envelope.
•
Wind conditions (e.g., tailwind component);
•
Type of braking used (i.e., pedal braking or
autobrake, use of thrust reversers);
The following information is provided for enhanced
understanding only.
•
Anti-skid failure;
The runway profile (i.e., downhill slope) affects the
landing distance without autobrake.
•
Incremental addition of all speed corrections on
the final approach speed;
A 1 % downhill slope increases the landing distance
without autobrake by 2 % (factor 1.02).
•
Deviation from the final approach speed;
•
Landing techniques (i.e., height and speed at
threshold, thrust reduction and flare technique);
•
Deviations from SOPs (e.g., failure to arm ground
spoilers);
•
MEL conditions (i.e., thrust reversers, brake unit,
anti-skid or ground spoilers inoperative); and,
•
In-flight system malfunctions resulting in an
increased final approach speed, or affecting the
lift-dumping or braking capability.
When autobrake is used, the selected deceleration
rate is achieved regardless of the runway slope.
Runway conditions:
Runway contamination increases the rolling drag
(i.e., the displacement drag) and the aerodynamic
drag (i.e., the impingement drag) but also decreases
the braking efficiency.
The following landing distance factors are typical on a
contaminated runway:
These factors are discussed hereafter and illustrated
in Figure 4.
Runway Condition
Factors
Airfield elevation:
Airfield elevation or a corresponding low QNH value
results in a higher TAS and ground speed and, thus,
in a greater landing distance.
At 1000-ft airfield elevation or at sea level with an
equivalent pressure altitude (i.e. with a low QNH of
980 hPa), the landing distance is increased by
5 % to 10 % (factor 1.05 to 1.10).
Wet
1.3 to 1.4
Standing water or slush
2.0 to 2.3
Compacted snow
1.6 to 1.7
Ice
3.5 to 4.5
Table 1
Landing Distance Factors - Contaminated Runway
Factors Affecting Landing Distance
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Briefing Note 8.5 - Landing on Contaminated Runway
provides expanded and illustrated information for
operation on runway contaminated with standing
water, slush, snow or ice.
At given gross weight ( GW ), any increment of or
deviation from V APP results in a corresponding
increase of energy ( ∆E ) such that:
∆E ( in % ) = 2 x ∆ VAPP ( in % )
Wind conditions:
The landing distance LD being a direct function of the
energy E, the corresponding increase in landing
distance ( ∆LD ) can be expressed also as:
In accordance with certification requirements and
operational regulations, the published landing
distance factors account for:
•
50 % of the head wind component; and,
•
150 % of the tail wind component.
∆LD ( in % ) = 2 x ∆ VAPP ( in % )
Note :
In pilot’s terms :
In case of gusting crosswind, a tailwind component
may exist but is not reported. This condition may be
undetected and therefore be not accounted for.
• a 10 % increase in final approach speed;
results in,
• a 20 % increase in landing distance.
Type of braking:
Actual landing distances are demonstrated during
certification flight tests using the following technique:
•
Flying an optimum flight segment from 50 ft over
the runway threshold down to the flare point;
•
Performing a firm touchdown; and,
•
Using full pedal braking, upon main landing gear
touchdown.
Note :
The above rule assumes a normal flare and
touchdown (i.e., not allowing the aircraft to float to
bleed off the excess speed).
Height over threshold:
Crossing the runway threshold at 100 ft results in an
increase of the landing distance of typically 1000 ft or
300 m, regardless of the runway condition and
aircraft model.
The published actual landing distances seldom can
be achieved in revenue service.
The landing distances published for automatic
landing with use of autobrake provide more
achievable references for line operations.
1000 ft/300 m
Speed Over Runway Threshold:
100 ft at threshold
The actual landing distance ( LD ) is a direct function
of the kinetic energy ( E ) to be absorbed.
50 ft at threshold
For an aircraft crossing the runway threshold at a
given gross-weight ( GW ) and at the final approach
speed ( V APP ), the kinetic energy is:
Figure 3
E = ½ .GW.( V APP )
2
Factors Affecting Landing Distance
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Flare technique:
Note:
On A300/A310 series, if ground spoilers do not
deploy automatically, the PF can manually extend the
ground spoilers using the speed brakes lever.
Performing a long flare (i.e., allowing the aircraft to
float to bleed off an excessive speed) further
increases the landing distance.
Delaying the derotation (i.e., the nose landing gear
touchdown) maintains a higher lift on main landing
gears for longer, resulting in less load on the main
landing gears and, hence, in less braking efficiency.
For example, a 5 % increase (excess) of the final
approach speed increases the landing distance by:
• 10 %, if a normal flare and touchdown is
performed (i.e., deceleration on the ground);
or,
This also delays the spin-up signal from the nosewheels; this signal is required for the optimum
operation of the anti-skid system.
• 30 %, if a long flare is performed
(i.e., deceleration while airborne).
MEL conditions:
When operating under the provision of the MEL
for an item affecting the landing speed, the liftdumping or the braking capability, the applicable
landing speed correction and landing distance factor
must be accounted for.
Performing a power-on touchdown in an attempt to
lessen an excessive rate-of-descent or to smooth out
the touchdown results in:
•
A long flare; and,
•
The inhibition of the automatic extension of
ground-spoilers.
Systems malfunctions:
This increases the risk of bouncing upon touchdown
and of a subsequent hard landing.
System malfunctions, such as an hydraulic system
low pres sure, may result in multiple effects on the
landing speed and landing distance, such as:
Ground spoiler not armed:
Failure to arm the ground spoilers (usually in
conjunction with thrust reversers being inoperative) is
frequently a causal factor in runway overruns.
The ground spoilers extend automatically when
reverse thrust is selected (regardless of whether the
ground spoilers are armed or not); this design feature
must not be relied upon for extension of ground
spoilers. Ground spoilers must be armed per SOPs.
Failure to arm the ground spoilers results in a typical
landing distance factor of 1.3 (1.4 if thrust reversers
are inoperative).
•
Landing speed correction due to slats or flaps
inoperative (i.e., restoring the stall margin);
•
Landing speed correction due to loss of roll
spoilers (i.e., restoring the maneuverability);
•
Landing distance factor due to loss of ground
spoilers (i.e., loss of lift dumping capability); and,
•
Landing distance factor due to loss of normal
braking system (i.e., reduced braking capability).
The FCOM and QRH provide the applicable final
approach speed corrections and landing distance
factors for all malfunctions (including their
consequential effects).
The automatic extension of ground spoilers should be
monitored and announced by calling Ground Spoilers
or No Spoilers.
Factors Affecting Landing Distance
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Combining Landing Distance Factors
Summary of key points
The landing distance factors provided in the FCOM
and QRH take into account all the consequential
effects associated with the primary malfunction.
When assessing the landing distance, the following
factors should be accounted for and combined, as
specified in the applicable FCOM / QRH:
No combination of landing distance factors is
needed, unless otherwise stated and explained.
•
Dispatch conditions, as applicable (dispatch
under minimum equipment list [MEL] / dispatch
deviation guide [DDG] );
•
In-flight failures, as applicable;
•
Weather conditions (e.g., icing conditions /
ice accretion);
•
Wind conditions (i.e., wind component and gust,
suspected wind shear);
•
Airfield elevation;
•
Runway slope (i.e., if down hill);
•
Runway condition (i.e., nature and depth of
contaminant); and,
•
Use of braking devices (e.g., thrust reversers,
autobrake).
Nevertheless, understanding the rules used to
combine landing distance factors provides an
enhanced understanding of the achievable landing
distance.
Landing distance factors result from:
•
•
A landing speed correction (e.g., because of
a failure affecting the stall margin or
maneuverability / controllability); or,
A reduced lift-dumping or braking capability (e.g.,
because of a failure affecting ground spoilers,
anti-skid or brakes).
Briefing Note 8.2 - The Final Approach Speed
provides the rules used for the combination of landing
speed corrections.
The following rules are used to combine
the different types of landing distance factors:
•
If landing speed corrections are added
(as
described
in
Briefing
Note
8.2),
the corresponding landing distance factors are
multiplied;
•
If only the higher speed correction is retained,
then only the higher landing distance factor is
considered; or,
•
When one or both of the two landing distance
factors is (are) related to lift-dumping or braking,
both landing-distance factors are multiplied.
Factors Affecting Landing Distance
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Landing Distance Summary
Figure 4 illustrates the landing distance factor for
different runway conditions or operational factors.
Required Landing Distance ( wet runway
)
1.92
Reference
( no reverse )
1000 ft elevation
10 kt tail wind
V Approach + 10 kt
100 ft at threshold
Long flare
No ground spoilers
Wet runway
Compacted snow
Water and slush
Icy runway
1.0
1.2
1.4
1.6
2.0
Landing Distance Factor
Factors Affecting Landing Distance
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Associated Briefing Notes
The following Briefing Notes provide expanded
information on braking issues, on dry, wet or
contaminated runway:
•
1.4 - Standard Calls,
•
6.4 - Bounce Recovery – Rejected Landing,
•
8.2 - The Final Approach Speed,
•
8.4 - Optimum Use of Braking Devices,
•
8.5 - Landing on Contaminated Runway.
Regulatory References
•
ICAO – Preparation of an Operations Manual
(Doc 9376),
•
FAR 121.97 or 121.117 – Airports: Required
Data,
•
FAR 121 Subpart I – Airplane Performance
Operating Limitations:
−
FAR 121.171 – Applicability,
−
FAR 121.195 – Airplanes: Turbine enginepowered: Landing limitations: Destination
airports,
−
FAR 121.197 – Airplanes: Turbine enginepowered: Landing limitations: Alternate
airports,
•
FAA – AC 91-6A and 91-6B – Water, Slush and
Snow on the Runway.
•
JAR-OPS 1.515 – Landing – Dry Runways,
•
JAR-OPS 1.520 – Landing
Contaminated Runways,
•
UK CAA – AIC 11/98 – Landing Performance of
Large Transport Aeroplanes,
•
UK CAA – AIC 61/99 – Risks and factors
Associated with Operations on Runways
Affected by Snow, Slush or Water.
–
Wet
and
Factors Affecting Landing Distance
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Approach-and-Landing Briefing Note
8.4 - Optimum Use of Braking Devices
Introduction
Braking Devices Overview
To ensure an optimum use of braking devices,
the following aspects must be understood:
The following braking devices are used to
decelerate the aircraft and bring it to a complete
stop:
•
Design and operation of each braking device
(i.e., ground spoilers, brakes and thrust
reversers);
•
Distribution of stopping forces during landing
roll;
•
Type of braking required to achieve a desired
stopping distance;
•
Factors affecting the optimum use of braking
devices; and,
•
•
Ground spoilers;
•
Wheel brakes (including anti-skid and autobrake
systems); and,
•
Thrust reverser system.
Ground spoilers:
Ground spoilers deploy automatically upon main
landing gear touchdown (if armed) or upon selection
of the thrust reversers.
Applicable operational guidelines.
Statistical Data
Ground spoilers provide two distinct aerodynamic
effects, as illustrated by Figure 1 :
Runway excursions and overruns account for 20 %
of all approach-and-landing serious incidents and
accidents.
•
Increased aerodynamic drag, which contributes
to aircraft deceleration;
•
Lift dumping, which increases the load on the
wheels and increases the wheel-brakes
efficiency.
Slowed or delayed braking action was a causal
factor in 45 % of these events.
Landing overruns represent 80 % of all observed
overrun events (i.e., including runway overruns
following a rejected takeoff).
The use of braking devices is only one among
several causal factors resulting in a runway
excursion or overrun.
Optimum Use of Braking Devices
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Negligible Weight
on Main Wheels
85 % Weight
on Main Wheels
60 % Weight
on Main Wheels
130 % Drag
Increase from
Ground Spoilers
Touchdown
V APP ( V LS )
Nose Wheel Down
Ground Spoilers Extended
Figure 1
Maximizing Weight-on-Wheels and Aerodynamic Drag
Wheel brakes:
Braking action results from the friction force
between the tires and the runway surface.
Tire Braking Force
Antiskid activation
100
This friction force depends on several parameters:
•
Aircraft speed;
•
Wheel speed (i.e., free rolling, skidding or
locked wheel);
80
70
Force ( % )
•
90
Runway condition (i.e., nature and depth of
contaminant);
60
50
40
30
20
•
Tire condition
surface);
and
pressure
(i.e.,
friction
•
The load applied on the wheel (i.e., the friction
force depends on the load applied on the wheel
and on the runway braking coefficient);
•
The number of operative brakes ( MEL status,
as applicable).
10
0
0
5
8
Free rolling wheel
10
15
20
30
40
50
Slip Ratio ( % )
60
70
80
90
100
Locked wheel
Figure 2
Tire Braking Force versus Slip Ratio
Anti-skid systems are designed to maintain the
wheel skidding factor (also called the slip ratio)
close to the point providing the maximum friction
force, approximately 10 % on a scale going from
0 % (free rolling) to 100 % (locked wheel), as
illustrated by Figure 2.
With anti-skid operative, full pedal braking results in
a deceleration rate of 8 knots-per-second to
10 knots-per-second on a dry runway.
Optimum Use of Braking Devices
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Autobrake System:
Autobrake system is designed to provide a selected
deceleration rate for enhanced passenger comfort,
typically between 3 knots-per-second and
6 knots-per-second, depending on the selected
mode.
When a low deceleration rate ( i.e., LOW mode ),
the brake pressure is applied after a specific time
delay to give priority to the thrust-reversers effect
high speed (Figure 3).
Runway conditions
Runway contamination increases:
Thrust reversers:
Thrust reversers provide a deceleration force that
is independent from the runway condition.
Thrust reverse efficiency is higher at high speed
(as illustrated by Figure 3); thrust reversers
therefore should be selected as early as possible
after touchdown (in accordance with applicable
SOPs).
•
Impingement drag (i.e., the drag resulting from
the spray of contaminant striking the landing
gear and airframe); and,
•
Rolling drag (i.e., the displacement drag).
Runway contamination also affects the braking
efficiency.
The following landing distance factors are typical on
wet or contaminated runway :
Thrust reversers should be returned to reverse idle
at low speed ( to prevent engine stall and/or foreign
objet damage caused by exhaust gas re-ingestion )
and stowed at taxi speed.
Runway Condition
Nevertheless, maximum reverse thrust can be
maintained down to a complete stop in an
emergency.
Factors
Wet
1.3 to 1.4
Standing water or slush
2.0 to 2.3
Compacted snow
1.6 to 1.7
Ice
3.5 to 4.5
Table 1
Reverse(d) thrust t t t t
Landing Distance Factors
Wet or Contaminated Runway
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Understanding a Typical Landing Roll
The resulting total stopping force ( red curve ) is the
combined effect of:
Figure 3 illustrates a typical landing roll and shows
the contribution of the different deceleration forces
to the total stopping force, as a function of
decelerating airspeed (i.e., from touchdown speed
to taxi speed).
•
Aerodynamic drag ( green curve );
•
Reverse thrust ( blue curve ); and,
•
Rolling drag ( purple curve ).
The ground spoilers are armed and the autobrake
system is selected with the LOW mode (i.e., for time
delayed brake application).
During the initial landing roll, the total stopping force
already exceeds the autobrake demand.
The autobrake demand in LOW mode (typically a
3 knots-per-second constant deceleration-rate) is
equivalent, at given gross weight, to a constant
stopping force ( pink dotted line ).
•
as long as the total stopping force exceeds the
autobrake demand; or,
•
until the autobrake time delay has elapsed.
At touchdown, the ground spoilers automatically
extend and the thrust reversers are selected with
the maximum reverse thrust.
As airspeed decreases, the total stopping force
decreases because of a corresponding decrease in:
Autobrake activation is, thus, inhibited:
•
aerodynamic drag; and,
•
reverse thrust
efficiency).
Typical Decelerating Forces during Landing Roll
Stopping Force
(i.e.,
decreasing
reverse
When the total stopping force becomes
lower than the autobrake demand (or when
the autobrake time delay has elapsed)
the wheel brakes begin contributing to the
total deceleration and stopping force.
Autobrake LOW Mode
Total Stopping Force
Typically at 80 kt IAS or when IAS
fluctuations occur, whichever come first, the
thrust-reverser levers are returned to the
reverse idle position (then to the stow
position, when reaching taxi speed).
Autobrake Demand
Aerodynamic Drag
Braking and
Rolling Drag
Maximum
Reverse
Thrust
Reverse Idle
Forward Idle
120
100
80
60
40
20
Airspeed ( kt )
Figure 3
As a result, the wheel-brakes’ contribution
(purple curve) increases in order to maintain
the desired deceleration rate (autobrake
demand) until the pilot takes over with pedal
braking.
This generic sequence of events is
applicable to any aircraft equipped with
ground spoilers, autobrake and thrust
reversers.
Stopping Forces Distribution
(Typical)
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Figure 4 provides the following information:
How do Ground Spoilers, Thrust Reversers
and Brakes Contribute to Stop the Aircraft?
•
Figure 4 illustrates the respective contributions of
the different braking devices to the total stopping
energy, as a function of the achieved or desired
stopping distance.
For a given braking mode (i.e., pedal braking or
autobrake mode):
−
•
Achieved stopping distance ( landing roll );
For a desired or required stopping distance:
−
Required type of braking (e.g., pedal
braking or autobrake mode).
Max Landing Weight - Sea Level - ISA - Dry runway
% of Total Stopping Energy
No Braking
Maximum pedal braking
( typically 8 to 10 kt/s )
80
Autobrake MED
( typically 6 kt/s )
70
60
Autobrake LOW
( typically 3 kt/s )
50
Aerodynamic Drag
40
Maximum Reverse Thrust
30
20
10
Braking and Rolling Drag
1000
2000
3000
Stopping Distance (m)
Figure 4
Stopping Energy Distribution versus Stopping Distance
(Typical)
Optimum Use of Braking Devices
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Factors Affecting Optimum Braking
Operational Guidelines and Key Points
The following factors often are involved in runway
excursions (i.e., aircraft veering off the runway or
taxiway), or in runway overruns:
Strict adherence to the following operational
standards and guidelines ensures optimum braking
during the landing roll:
•
•
Arm ground spoilers;
•
Arm autobrake with the most appropriate mode
for prevailing conditions (short runway, runway
with downhill slope, low visibility, contaminated
runway);
•
Select thrust reversers as soon as possible with
maximum reverse thrust ( this increases safety
on dry and wet runway, and is mandatory on
runway contaminated with standing water, slush,
snow or ice );
•
Monitor and call ground spoilers extension;
•
Monitor and call autobrake operation;
•
Be ready to take over from autobrake, if
required;
•
Monitor engine operation in reverse thrust
(e.g., increasing EGT and/or evidence of surge);
•
Monitor airspeed indication and return reverse
levers to the reverse idle position at the
published indicated airspeed or when airspeed
fluctuations occur, whichever come first;
•
If required, use maximum pedal braking; and,
•
Do not stop braking until assured that the
aircraft will stop within the remaining runway
length.
Failure to arm ground spoilers, with thrust
reversers deactivated (e.g., reliance on thrust
reverser signal for ground spoilers extension);
•
Failure to use any braking devices (i.e., use of
the inappropriate nose high “aerodynamic
braking” technique);
•
Asymmetric thrust (i.e. one engine being above
idle level in forward thrust or one engine failing
to go into reverse thrust);
•
Brake unit inoperative (i.e., brake unit reported
as “cold brake” for several flights, without
corresponding MEL entry);
•
Anti-skid tachometer malfunction;
•
Absence of switching or late switching from
NORM braking to ALTN braking or to
emergency braking in case of abnormal braking;
•
Late selection of thrust reversers;
•
Absence of takeover or late takeover from
autobrake, when required;
•
Inadequate crosswind landing technique; and,
•
Incorrect differential braking technique.
Optimum Use of Braking Devices
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Associated Briefing Notes
The following Briefing Notes provide expanded
information on landing performance and techniques:
•
8.3 - Factors Affecting Landing
Distances,
•
8.5 - Landing on Wet and Contaminated
Runway,
•
8.7 - Crosswind Landing.
Regulatory References
•
ICAO – Preparation of an Operations Manual
(Doc 9376),
•
FAR 121.97 or 121.117 – Airports: Required
Data,
•
FAR 121 Subpart I – Airplane Performance
Operating Limitations:
−
FAR 121.171 – Applicability,
−
FAR 121.195 – Airplanes: Turbine enginepowered: Landing limitations: Destination
airports,
−
FAR 121.197 – Airplanes: Turbine enginepowered: Landing limitations: Alternate
airports,
•
FAA – AC 916A and 91-6B,
•
JAR-OPS 1.515 – Landing – Dry Runways,
•
JAR-OPS 1.520 – Landing
Contaminated Runways,
•
UK CAA – AIC 11/98 – Landing Performance of
Large Transport Aeroplanes,
•
UK CAA – AIC 61/99 – Risks and factors
Associated with Operations on Runways
Affected by Snow, Slush or Water.
–
Wet
and
Optimum Use of Braking Devices
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Approach-and-Landing Briefing Note
8.5 - Landing on Wet or Contaminated Runway
Introduction
Damp runway:
Factors associated with landing on a wet runway or
on a runway contaminated with standing water,
slush, snow or ice should be assessed carefully
before beginning the approach.
A runway is considered damp “when the surface is
not dry, but when the moisture on the surface does
not give a shiny appearance”.
Wet runway:
This Briefing Note provides an overview and
discussion of operational factors involved in
planning and conducting a landing on a wet or
contaminated runway.
A runway is considered to be wet “when the surface
is covered with water, or equivalent, not exceeding
3 mm - or when there is sufficient moisture on the
runway surface to cause it to appear reflective
(shiny) - but without significant areas of standing
water”.
Statistical Data
Runway condition, alone or in combination with
adverse crosswind, is a circumstantial factor
in 75 % of runway excursions or runway overruns at
landing.
Contaminated runway:
A runway is considered to be contaminated “when
more than 25 % of the runway surface (whether in
isolated areas or not) - within the required length
and width being used – is covered by either:
Runway contamination with standing water, slush,
snow or ice is a causal factor in 18 % of all landing
accidents.
Defining the Runway Condition
•
Standing water, more than 3 mm (1/8 inch)
deep;
•
Slush (i.e., water saturated with snow) or loose
snow, equivalent to 3 mm (1/8 inch) - or more of water;
•
Snow which has been compressed into a solid
mass which resists further compression and will
hold together or break into lumps if picked up
(i.e., compacted snow); or,
•
Ice, including wet ice contaminant (runway
friction coefficient 0.05 or below)”.
The European JAA defines the runway condition as
follows:
Dry runway:
A dry runway is “one that is neither wet nor
contaminated”.
This “includes paved runways that have been
specially prepared with grooved or porous pavement
and maintained to retain an effectively dry braking
action, even when moisture is present”.
Uncleaned rubber deposits in the touchdown zone
result in the runway surface to be slippery-whenwet.
Landing on Wet or Contaminated Runway
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Hydroplaning results in a partial or total reduction of
contact surface between the tire and the runway and
in a corresponding loss of friction coefficient.
Factors and Effects
Braking action:
Main-wheels and nose-wheels equally can be
affected by hydroplaning, thus affecting the braking
performance and the effectiveness of the nosewheel-steering.
The presence of fluid contaminant (i.e., standing
water, slush or loose snow) or hard contaminant
(i.e., compacted snow or ice) on the runway
adversely affects the braking performance (stopping
force) by:
•
Hydroplaning always occurs in some degree when
operating on a fluid-contaminated runway.
Reducing the friction force between the tires and
the runway surface.
The reduction of friction force depends on the
following factors:
The potential for severe hydroplaning directly
depends on the following factors:
− tire tread condition (wear) and inflation
pressure;
•
Absence of runway surface roughness and
drainage (e.g., transverse saw-cut grooves);
− type of runway surface; and,
•
Thickness and nature (e.g., water or slush)
of the fluid contaminant layer;
•
Tire inflation pressure;
•
Ground speed; and,
•
Antiskid operation (e.g., locked-wheel case).
− anti-skid system performance.
•
Creating a fluid layer between the tires and
the runway surface, thus reducing the contact
area and creating a risk of hydroplaning
(i.e., complete loss of contact and friction
between the tires and the runway surface).
A minimum hydroplaning speed can be defined for
each aircraft type and runway contaminant.
Fluid contaminants (such as standing water, slush
or loose snow) also positively contribute to the
stopping force at landing by:
•
•
Hydroplaning may occur at touchdown, preventing
the wheels from spinning and from sending the
wheel-rotation-signal to various aircraft systems.
Resisting to the wheels forward movement, thus
causing a displacement drag;
Performing a firm touchdown can prevent
hydroplaning at touchdown and ensure rotation of
main-landing-gear wheels.
Creating a spray pattern that strikes the landing
gears and airframe, thus causing an
impingement drag.
Directional control:
Certification regulations require the spray
pattern to be diverted away from engine air
inlets to prevent affecting engine performance.
On contaminated runway, directional control should
be maintained using rudder pedals (do not use
nose-wheel-steering tiller until aircraft has slowed
down to taxi speed).
The braking action is the net effect of the above
stopping forces (as illustrated by Figure 1 and
Figure 2).
On wet or contaminated runway, use of nose-wheelsteering above taxi speed may result in
hydroplaning of nose-wheels, hence in loss of nosewheels cornering force and, thus, in loss of
directional control.
Hydroplaning (aquaplaning):
Hydroplaning occurs when the tire cannot squeeze
any more of the fluid contaminant layer between its
tread and the runway surface; the tire lifts from the
runway surface and surfs the wave of water.
If differential braking is necessary, pedal braking
should be applied on the required side and be
completely released on the opposite side, to regain
tire cornering.
Landing on Wet or Contaminated Runway
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Briefing Note 8.7 - Crosswind Landing provides
expanded information on directional control under
crosswind conditions.
Understanding
Landing Roll
Landing distances are provided in the FCOM and
QRH for a dry runway and for the following runway
conditions and contaminants:
Wet;
•
6.3 mm (1/4 inch) standing water;
•
12.7 mm (1/2 inch) standing water;
•
6.3 mm (1/4 inch) slush;
•
12.7 mm (1/2 inch) slush;
•
Compacted snow; and,
•
Ice.
•
Aerodynamic drag, including the impingement
drag ( green curve );
Note :
•
An even distribution of the contaminant;
•
The use of full pedal braking beginning at
touchdown; and,
•
An operative anti-skid system.
The term aerodynamic drag refers to the drag of
the airplane during the rollout (including the
impingement drag, on fluid contaminated
runway), not to the (inappropriate) technique of
keeping the nose high to (supposedly) increase
the overall aerodynamic stopping force.
Autoland landing distances using autobrake are
published for all runway conditions.
•
Reverse thrust ( blue curve ); and,
•
Braking and rolling drag, including
displacement drag ( red curve ).
Stopping
Force
Airport elevation:
Autobrake LOW Mode
− Typically, + 5 % per 1000 ft;
Total Stopping Force
Wind component:
− Typically, + 10 % per 5 kt tailwind component;
Autobrake Demand
Aerodynamic Drag
− Typically, – 2.5 % per 5 kt headwind
component; and,
•
the
Typical Decelerating Forces during Landing Roll
In addition, correction factors (in %) are provided to
account for the following effects:
•
during
The total stopping force is the combined effect of:
Actual landing distances are provided for all runway
conditions and assume:
•
Forces
Figure 1 shows the distribution of the respective
stopping forces, as a function of the decreasing
airspeed, during a typical landing roll using
autobrake in LOW mode and maximum reverse
thrust ( see also Briefing Note 8.4 - Optimum Use
of Braking Devices ).
Assessing Landing Distance
•
Stopping
Braking and
Rolling Drag
Maximum
Reverse
Thrust
Thrust reversers effect:
− Thrust reverser effect depends on runway
condition and type of braking, as illustrated
by Figure 4.
140
120
100
80
Airspeed ( kt )
Figure 1
Landing on Wet or Contaminated Runway
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Distribution
The contribution of the different braking devices to
the total stopping energy on a runway contaminated
with ¼ inch of standing water can be compared to
their respective contributions on a dry runway, as
illustrated in Briefing Note 8.4 – Optimum Use of
Braking Devices, Figure 4 ):
on
Figure 2 illustrates the contribution to the total
stopping energy of the different braking devices, as
a function of the desired or achieved stopping
distance, on a runway contaminated with ¼ inch of
water.
•
The contribution of the aerodynamic drag
increases due to the additional impingement
drag;
•
The contribution of the braking and rolling drag
(i.e., net effect of braking force and
displacement drag) decreases;
•
The contribution of the thrust reverser stopping
force is independent from the runway condition.
Figure 2 provides:
•
The stopping distance ( landing roll ) achieved
for a given type of braking (i.e., pedal braking or
selected autobrake mode);
or,
•
The necessary type of braking (i.e., pedal
braking or selected autobrake mode) for a
desired or required stopping distance.
Given Aircraft - Maximum Landing Weight - V APP – Both Reversers
Sea Level - ISA – ¼ Inch Water
Maximum pedal braking ( typically – 5 kt/s )
% of Stopping Energy
Autobrake medium ( typically – 4 kt/s )
Autobrake low ( typically – 3 kt/s )
80
No braking
70
60
Aerodynamic Drag
50
40
Maximum Reverse Thrust
30
20
10
Braking and Rolling Drag
0
1000
2000
3000
Stopping ( Landing ) Distance (m)
Figure 2
Landing on Wet or Contaminated Runway
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On runway contaminated by standing water or
slush, the landing distances with medium or low
autobrake settings are very similar, because:
Factors Affecting Landing Distance
Runway condition and type of braking:
Figure 3 illustrates the effect of runway condition on
landing distance, for various applicable runway
conditions and for three braking modes.
•
The deceleration rate is driven primarily by the
aerodynamic drag, rolling drag and reverse
thrust; and because,
•
The selected autobrake deceleration rate
( e.g., when using a medium autobrake mode )
cannot be achieved; the light indicating that the
selected deceleration rate is achieved does not
illuminate.
Effect of Braking and Runway Condition
4000
Thrust reverser:
3000
2500
Figure 4 illustrates the effect of reverse thrust
(i.e., reduction of landing distance, in %) with both
reversers operative.
2000
Manual Landing
Pedal Braking
Autoland
Autobrake Medium
Autoland
Autobrake Low
When autobrake is used, the thrust reverser effect
(i.e., contribution to the landing distance reduction)
depends on:
Ice
no
w
ds
•
The selected deceleration rate and the time
delay for autobrake activation, as applicable;
and,
•
Runway condition (i.e., contribution
contaminant to the deceleration rate).
Runway condition
Figure 3
( Typical )
of
Effect of Thrust Reverser
Figure 3 is based on a reference 1000-m landing
distance ( typical landing distance for a manual
landing on dry runway with full pedal braking and no
reverse ).
•
Landing distance for autoland with low or
medium autobrake.
Landing Distance Reduction (%)
Landing distance for manual landing with
full pedal braking; or,
For manual landing with full pedal braking or for
autoland with autobrake, the effect of runway
condition can be assessed.
5
10
15
20
25
Manual Landing
Pedal Braking
30
Autoland
Autobrake Medium
35
Autoland
Autobrake Low
40
When autobrake is used, the braking contribution
depends on the selected deceleration rate and on
the anti-skid activation point, whichever is achieved
first, as illustrated by Figure 3 and Figure 4.
Figure 4
( Typical )
Landing on Wet or Contaminated Runway
Page 5
ed
Ic e
pa
ct
Co
m
s lu
sh
in
1 /2
in
s lu
sh
wa
te r
in
0
For each runway condition, the following landing
distances can be compared:
•
1 /4
Dr
y
wa
te r
sn
ow
Runway Condition
1 /2
h
slu
s
1/2
Co
mp
ac
te
in
h
slu
s
1/4
in
wa
ter
1/2
in
wa
ter
1/4
in
We
t
Dr
y
0
in
500
1 /4
1000
t
1500
We
Landing distance (m)
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On dry or wet runway, the effect of thrust reverser
on landing distance depends on the selected
autobrake mode (i.e., selected deceleration rate)
and associated time-delay (e.g., medium autobrake
mode without time delay versus low autobrake
mode with time delay), as illustrated by Figure 1
and Figure 4.
Operational Guidelines
The operational guidelines provide in Briefing Note
8.4 - Optimum Use of Braking Devices, for
operation on dry runway, are fully applicable when
operating on a wet runway or on a runway
contaminated with standing water, slush, snow or
ice.
•
Aiming for the touchdown zone;
•
Performing a firm touchdown (to prevent
hydroplaning and ensure rotation of main
landing gear wheels);
•
Using maximum reverse thrust as soon as
possible after touchdown (because thrust
reverser efficiency is higher at high speed);
•
Confirm the extension of ground spoilers;
•
Monitoring the operation of autobrake (on
contaminated runway, the selected deceleration
rate may not be achieved, therefore the light
indicating that the selected deceleration rate is
achieved may not illuminate);
•
Lowering the nose landing gear without undue
delay to:
The following operational recommendations need to
be emphasized:
•
Diversion to an airport with better runway
conditions and/or less crosswind component,
when actual conditions significantly differ from
forecast conditions or in case of system
malfunction;
−
increase the weight-on-wheels and, thus,
increase the braking efficiency; and,
−
activate systems associated with nose
landing gear switches (e.g., anti-skid
reference speed);
•
Anticipating asymmetry effects that would
prevent efficient braking or directional control
(e.g.,
crosswind,
single-thrust-reverser
operation);
As required, or when taking over from
autobrake, applying brakes normally with a
steady pressure;
•
Using rudder pedals and differential braking, as
required, for directional control (i.e., not using
the nose-wheel-steering tiller);
•
Avoiding landing on a contaminated runway
without antiskid or with a single thrust reverser.
•
•
For inoperative items affecting the braking or lift
dumping capability, referring to the applicable:
If differential braking is necessary, applying
pedal braking on the required side and releasing
completely the pedal action on the opposite
side; and,
•
After reaching taxi speed, using nose-wheelsteering with care.
•
•
−
FCOM and QRH, for in-flight malfunctions,
or,
−
Minimum Equipment List (MEL) or Dispatch
Deviation Guide (DDG), for known dispatch
conditions;
Associated Briefing Notes
The following Briefing Notes provide expanded
information for a complete overview of factors
involved when landing on a contaminated runway:
Selecting autobrake with a medium or low
setting, if the contaminant is evenly distributed);
On contaminated runway, use of medium setting
usually is recommended to assure immediate
braking action after touchdown (i.e., without time
delay).
•
Approaching on glide path and at the target final
approach speed;
•
7.1 - Flying Stabilized Approaches,
•
8.3 - Factors Affecting Landing
Distances,
•
8.4 - Optimum Use of Braking Devices,
•
8.7 - Crosswind Landing.
Landing on Wet or Contaminated Runway
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Regulatory references
•
ICAO – Preparation of an Operations Manual
(Doc 9376),
•
FAR 121.97 or 121.117 – Airports: Required
Data,
•
FAR 121 Subpart I – Airplane Performance
Operating Limitations:
−
FAR 121.171 – Applicability,
−
FAR 121.195 – Airplanes: Turbine enginepowered: Landing limitations: Destination
airports,
−
FAR 121.197 – Airplanes: Turbine enginepowered: Landing limitations: Alternate
airports.
•
FAA – AC 91-6A – Water, Slush and Snow on
the Runway,
•
JAR-OPS 1.515 – Landing – Dry Runways,
•
JAR-OPS 1.520 – Landing
Contaminated Runways,
•
UK CAA – AIC 11/98 – Landing Performance of
Large Transport Aeroplanes,
•
UK CAA – AIC 61/99 – Risks and factors
Associated with Operations on Runways
Affected by Snow, Slush or Water.
–
Wet
and
Landing on Wet or Contaminated Runway
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Approach-and-Landing Briefing Note
8.6 - What’s Your Current Wind ?
Introduction
Defining Average-Wind and Gust
Several sources of wind information are available to
the flight crew:
Wind direction and velocity are sampled every
second.
•
ATC (i.e., METAR, ATIS and tower winds); and,
•
Aircraft systems (i.e. IRS and FMS winds).
The wind profile is averaged over the last
2-minute period to provide the ATIS or towerreported average-wind.
Each wind information must be understood for
appropriate use during various flight phases.
The average wind is available to the controller on
a display terminal ( some control towers, however,
can also provide instantaneous indications of wind
direction and velocity ).
Statistical Data
The wind profile is also observed over the last
10-minute period, the maximum ( peak ) wind value
recorded during this period defines the gust value.
Adverse wind conditions (i.e., tail wind component,
high crosswind component, wind gustiness or low
level wind shear) are involved in more than 30 %
of landing incidents and accidents.
Because wind sensors often are distant from
the touchdown zone, wind conditions at touchdown
frequently differ from conditions reported by ATC.
ICAO considers that the wind is gusty only if the
10-minute peak value exceeds the 2-minute
average-wind by 10 kt or more, however gust values
lower than 10 kt often are provided by airport
weather services.
ICAO Standards
Figure 1 shows a 10-minute wind profile featuring:
Recommendations for measuring and reporting
wind information are defined by the International
Civil Aviation Organization (ICAO) and:
•
Relayed
to
the
Organization (WMO);
World
•
A 2-minute average wind of 15kt; and,
•
A 10-minute gust of 10 kt (i.e., a 25 kt peak wind
velocity during the 10-minute period).
Meteorological
•
Implemented by the member states’ National
Weather Services (NWS);
•
Through the local Airport Weather Services
(AWS).
Note:
The ATIS and tower winds are referenced to the
magnetic north (unless all airport directions are
referenced to the true north, for example in regions
with large magnetic variation).
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Average-wind and gust values displayed to the
controller are refreshed every minute.
Wind ( kt )
Gust
25
Average
Wind
20
The 2-minute average-wind and the 10-minute gust
are used by ATC for:
15
•
ATIS messages;
10
•
Wind information on GND, TWR, APP and
INFO frequencies.
5
0
0
1
2
3
4
5
6
7
8
9
10
Minutes
METAR observation messages include a 10-minute
average-wind and the 10-minute gust, as illustrated
by Figure 3 ( XXX is the wind direction, referenced
to the true north).
Wind 15 kt Gusting 25 kt
Wind ( kt )
Figure 1
Gust
25
20
If the wind peak value is observed during the last
2-minute period, the gust becomes part of the
average wind, as illustrated by Figure 2.
Average
Wind
15
10
Wind ( kt )
5
25
Average
Wind
0
0
20
1
2
3
4
5
6
7
8
9
10
Minutes
15
METAR - Wind XXX15G23KT
10
Figure 3
5
0
0
1
2
3
4
5
6
7
8
9
10
Minutes
Maximum Demonstrated Crosswind
The maximum demonstrated crosswind, published
in the Performance section of the approved
Airplane Flight Manual (AFM), is the maximum
crosswind component that has been encountered
and documented during certification flight tests or
subsequently.
Wind 20 kt Gusting 25 kt ( * )
Figure 2
The wind value is recorded during a period
bracketing the touchdown time ( typically from
100 ft above airfield elevation down to taxi speed ).
( * ) : or no reference to gust if the 5-kt gust is not
accounted for.
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For some aircraft models, if a significant gust could
be recorded during this period, a demonstrated gust
value is also published in the AFM and FCOM.
Factors Affecting Crosswind Capability
The following factors, runway conditions
configurations affect the crosswind capability:
or
The maximum demonstrated crosswind:
•
Is not an operating limitation;
•
Does not necessarily reflect the
maximum crosswind capability; and,
•
Generally applies to a steady wind.
aircraft
Nevertheless, a survey conducted by Airbus
Industrie indicates that 75% of operators consider
the maximum demonstrated crosswind as
a limitation.
50% of operators consider that only the ATIS
and tower average-wind must be lower than the
maximum demonstrated crosswind; and,
•
50% of operators consider that the ATIS and
tower gust must be lower than the maximum
demonstrated crosswind.
Runway condition (i.e., nature and depth of
contaminant);
•
Systems malfunctions (e.g., rudder jam); or,
•
MEL conditions (e.g. nose wheel steering
inoperative).
Wind Information on Navigation Display
Wind information on the navigation display (ND)
consists of two elements, as shown on Figure 4:
When no demonstrated gust value is available:
•
•
•
− The direction of the wind arrow is referenced
to the magnetic north ( because the magnetic
north is the reference for the ND map ) and
reflects the wind direction;
− The length of the wind arrow is fixed (i.e., the
length does not vary with varying wind
velocity).
The majority of operators have published and
implemented reduced crosswind limits for operation
on contaminated runway.
The wind arrow is the primary wind visual-cue
during the final approach ( together with the
ground speed [GS] display ).
The crosswind limits published by operators for dry
or wet runway and for runway contaminated with
standing water, slush, snow or ice often are lower
( by typically 5 kt ) than the demonstrated values or
recommended values published by Airbus Industrie.
•
The maximum computed crosswind reflects the
computed design capability of the aircraft in terms
of:
Rudder authority;
•
Roll control authority; and,
•
Wheel-cornering capability.
A digital wind information that provide the wind
direction (referenced to the true north) and wind
velocity.
The digital wind information is primarily used to
compare the current wind to the predicted wind
provided on the computerized flight plan.
Maximum Computed Crosswind
•
A wind arrow:
Depending on aircraft models and standards, the
wind information may be computed either by the
inertial reference system (IRS) or by the flight
management system (FMS).
Depending on the wind source, different time delays
are applied for smoothing (i.e., averaging) the wind
value.
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The wind information on the ND is refreshed
typically 10 times per second.
GS 482
TAS 468
17
16
18
19
20
The IRS wind is computed and transmitted to the
aircraft electronic flight instrument system (EFIS) for
display on the navigation display (ND) typically
10 times per second.
The IRS wind display is therefore a near-real-time
wind information.
180 °
CDN
50 NM
FMS Wind
21
15
22
14
The FMS wind is computed similarly to the IRS wind
but with the following differences:
AMB
•
The accuracy of the ground speed received
from the IRS is increased by including a
correction based on the DME-DME position or
GPS position, when available; and,
•
The FMS wind is averaged over a 30-second
period.
80
CDN
40
Because of this 30-second smoothing, the FMS
wind is less accurate under the following conditions:
212/20
Figure 4
(Typical display)
•
Shifting wind;
•
Sideslip; or,
•
Climbing or descending turn.
The FMS wind cannot be considered as
an instantaneous wind but, nevertheless, the FMS
wind is:
IRS Wind
•
The IRS wind is assessed geometrically using the
triangle consisting of the true air speed (TAS)
vector, ground speed (GS) vector and wind vector.
A more recent wind information than the ATIS or
tower average wind; and,
•
The wind prevailing along the aircraft flight path
(aft of the aircraft).
The TAS vector and GS vector are defined by their
velocity and direction, as follows:
Summary of Key Points
•
The METAR wind is a 10-minute-average wind.
TAS vector:
− velocity: TAS from the air data computer
(ADC);
The ATIS or tower average wind is a 2-minuteaverage wind.
− direction: magnetic heading from IRS.
•
The ATIS or tower gust is the wind peak value
during the last 10-minute period.
GS vector:
− velocity: GS from IRS;
The ATIS message is updated only if the wind
direction changes by more than 30-degree or if the
wind velocity changes by more than 5-kt over
a 5-minute time period.
− direction: magnetic track from IRS.
What’s Your Current Wind ?
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If an instantaneous wind reading is desired and
requested from the ATC, the phraseology
“ instant-wind “ should be used in the request (some
controllers may provide such instant-wind without
request under shifting and/or gusting wind
conditions).
The IRS wind is a near-real-time wind.
The FMS wind is a 30-second-average wind.
The maximum demonstrated crosswind generally
applies to a steady wind and is not a limitation
(unless otherwise stated).
Depending on the flight phase and on the intended
use, flight crews should select the most appropriate
source of wind information.
Associated Briefing Notes
The following Briefing Notes provide expanded
information for a complete awareness of
wind-related factors:
•
8.5 - Landing on Wet or Contaminated
Runway.
•
8.7 - Crosswind Landing,
Regulatory References
•
ICAO - Annex 3 – Meteorological Service for
International Air navigation, Chapter 4.
•
ICAO - Annex 11 – Air Traffic Services.
•
World Meteorological Organization (WMO)
Guide to Meteorological Instruments and
Methods of Observation (WMO – No 8).
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Approach-and-Landing Briefing Note
8.7 – Crosswind Landings
Introduction
On a runway contaminated with standing water,
slush, snow or ice, a maximum recommended
crosswind is defined (Table 1), depending on:
Operations in crosswind conditions require strict
adherence to applicable crosswind limitations or
maximum
recommended
crosswind
values,
operational
recommendations
and
handling
techniques, particularly when operating on wet or
contaminated runways.
This Briefing Note provides an overview and
discussion of operational factors involved in planning
and conducting the approach and flare under
crosswind conditions, particularly on a contaminated
runway.
Briefing Note 8.5 – Landing on Wet or Contaminated
Runway provides expanded information on operations
on wet or contaminated runways.
•
Reported braking action (if available); or,
•
Reported
runway
(if available); or,
•
Equivalent runway condition (if braking action and
runway friction coefficient are not available).
Reported
Runway
Friction
Coefficient
Equivalent
Runway
Condition
Maximum
Recommended
Crosswind
Good
0.40 and
above
Note 1
35 kt
0.36 to 0.39
Note 1
30 kt
0.30 to 0.35
Note 2 and
Note 3
25 kt
0.26 to 0.29
Note 2 and
Note 3
20 kt
0.25 and
below
Note 3 and
Note 4
15 kt
Unreliable
Note 4 and
Note 5
5 kt
Good /
Medium
Adverse wind conditions (i.e., strong crosswinds,
tail winds and wind shear) are involved in 33 % of
approach-and-landing accidents.
(4)
Medium
(3)
Crosswind in association with runway condition is a
circumstantial factor in nearly 70 % of runway
excursion events.
Medium /
Poor
85 % of crosswind incidents and accidents occur
at landing.
(2)
Poor
Runway
Condition
and
Recommended Crosswind
coefficient
Reported
Braking
Action
( Index )
(5)
Statistical Data
friction
(1)
Maximum
Unreliable
The maximum demonstrated crosswind and
maximum computed crosswind, discussed in Briefing
Note
8.6
–
What’s
your
Current
Wind ?, are applicable only on dry, damp or wet
runway.
(9)
Table 1
Maximum Recommended Crosswind - Typical
Crosswind Landings
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Final Approach Technique
The Equivalent Runway Condition, defined by
Note 1 through Note 5, can be used only for the
determination of the maximum recommended
crosswind.
Figure
1 shows that depending on the
recommendations published in the aircraft-operating
manual, the final approach under crosswind
conditions may be conducted :
This Equivalent Runway Condition cannot be used
for the computation of takeoff and landing
performance, because it does not account for the
effects of the displacement drag and impingement
drag ( as defined in Briefing Note 8.5 – Landing on
Wet or Contaminated Runway ).
Note 1 :
Dry, damp or wet runway (i.e., less than 3mm water
depth) without risk of hydroplaning.
•
With wings-level (i.e., applying a drift correction
in order to track the runway centerline, this type
of approach is called a crabbed approach); or,
•
With a steady sideslip (i.e., with the aircraft
fuselage aligned with the runway centerline,
using a combination of into-wind aileron and
opposite rudder to correct the drift).
Note 2 :
Runway covered with slush.
Note 3 :
Runway covered with dry snow.
Note 4 :
Runway covered with standing water, with risk of
hydroplaning, or with wet snow.
Note 5 :
Runway with high risk of hydroplaning.
The maximum recommended crosswind on
a contaminated runway is based on computation
rather than flight tests, but the calculated values are
adjusted in a conservative manner based on
operational experience.
Some operators consider reduced maximum
crosswind values when the first officer is PF, during
line training and initial line operation.
Crabbed Approach
Sideslip Approach
Figure 1
The maximum crosswind for performing an autoland
is a certified limitation.
Crabbed Approach versus Sideslip Approach
Assignment by ATC of a given landing runway should
be questioned by the PF if prevailing runway
conditions and crosswind component are considered
inadequate for a safe landing.
This Briefing Note focus on the wings-level / crabbed
approach technique, recommended by Airbus
Industrie, to discuss the associated flare and decrab
techniques depending on the crosswind component.
Crosswind Landings
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•
Airframe manufacturers consider the following factors
when recommending a wings-level or a steady-sideslip approach :
•
Aircraft geometry (i.e., pitch attitude and bank
angle limits for preventing tail strike, engine
nacelle contact or wingtip contact);
•
Ailerons (roll) and rudder (yaw) authority; and,
•
Crosswind component.
Bank angle at a given crab angle or crab angle at
a given bank angle:
− The graph provides the bank angle / crab
angle relationship required to correct the drift
and track the runway centerline at the final
approach speed ( V APP ) in a steady -side-slip
condition.
Positive crab angles reflect normal drift
corrections and sideslip conditions (i.e., with
the aircraft pointing into wind).
Negative crab angles result from an excessive
rudder correction (i.e., aircraft pointing away
from wind direction) and require a more-thandesired bank angle to maintain a steadysideslip.
Flare Technique
Approaching the flare point with wings-level and with
a crab angle, as required for drift correction, three
flare techniques are possible (depending on runway
condition, crosswind component and company
SOPs):
•
Align the aircraft with the runway centerline, while
preventing drifting sideways, by applying intowind aileron and opposite rudder (cross-controls);
•
Perform a partial decrab, using the cross-controls
technique to continue tracking the runway
centerline; or,
•
•
− This limitation reflects the maximum pitch
attitude and/or bank angle that can be
achieved without incurring a tail strike or
scrapping the engine nacelle, the flaps or
the wingtip (as applicable).
•
Crosswind
Ailerons / rudder authority :
− This limitation reflects the aircraft maximum
capability to maintain a steady -sideslip under
crosswind conditions.
Maintain the crab angle, for drift correction, until
main-landing-gear touchdown.
Understanding
Limitations
Aircraft geometry limitation :
Figure 2 and Figure 3 assume that the approach is
stabilized and that the flare is performed at a normal
height and with a normal pitch rate.
Landing
These figures may not be available and published for
all aircraft types and models, but all aircraft are
subject to the same basic laws of flight dynamics
that these figures reflect.
The following discussion of flight dynamics can
provide an increased understanding of the various
crosswind landing techniques (i.e., final approach,
flare and align phases):
Geometry limits usually are not a concern in high
crosswinds as the roll and rudder authority is
reached before any aircraft-to-ground contact occurs.
Crosswind landing capability – Design factors
Figures 2 and Figure 3 illustrate the limitations
involved in crosswind landing (for a given steady
crosswind component).
This assumes achieving a steady sideslip without
overcontrol (i.e., without excessive rudder and roll
inputs) during the decrab / align phase.
Crosswind Landings
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Crab Angle versus Bank Angle
Typical - Maximum Landing Weight - Landing Configuration - 10 kt Crosswind
16
14
12
10
8
Pitch Attitude Limit
Crab Angle (Degree)
6
B
X
4
Roll / Rudder Limit
0 Degree Bank-Angle
2
2 Degree
AX
0
4 Degree
-2
6 Degree
-4
8 Degree
-6
10 Degree
-8
12 Degree
-10
-12
-14
115
120
130
140
V APP
150
160
Indicated Airspeed (kt)
Figure 2
Crab Angle versus Bank Angle
Typical - Maximum Landing Weight - Landing Configuration - 30 kt Crosswind
16
B
14
Pitch Attitude Limit
Crab Angle (Degree)
X
12
Roll / Rudder Limit
10
0 Degree Bank-Angle
8
2 Degree
6
4 Degree
4
6 Degree
C X
8 Degree
2
10 Degree
0
AX
XD
12 Degree
-2
-4
-6
-8
-10
-12
-14
115
120
130
V APP
140
Indicated Airspeed (kt)
Figure 3
Crosswind Landings
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Figure 2 shows that with a 10 kt steady crosswind
component:
•
•
Operational
techniques
Achieving a steady sideslip landing (i.e., with
zero crab angle) requires only a 3-degree
into-wing bank angle ( point A plotted on the
graph ); or,
•
Achieving a wings level touchdown (i.e., with no
decrab) only requires a 4-degree to 5-degree crab
angle at touchdown ( point B ).
handling
With low crosswind ( typically up to 15 kt to 20
kt crosswind component ), a safe crosswind
landing (i.e., flare and touchdown) can be
performed with either:
− A steady-sideslip (i.e., no crab angle); or,
− Wings-level,
touchdown.
•
Figure 3 shows that with a 30 kt steady crosswind
component:
•
and
Figure 2 and Figure 3 shows that:
A steady-sideslip landing can be performed safely
(i.e., while retaining significant margins relative to
geometry or roll / rudder limits).
•
recommendations
Achieving a steady-sideslip landing (i.e., with
zero crab angle) requires nearly a 9-degree intowind bank angle, placing the aircraft closer to its
geometry and roll /r udder limits ( point A on the
graph ); or,
with
no
decrab
prior
to
With higher crosswind ( typically above 15 kt to
20 kt crosswind component ), a safe crosswind
landing requires:
−
a crabbed-approach; and,
−
a partial decrab prior to touchdown, using
a combination of bank angle and crab angle
(achieved by applying cross-controls).
On most Airbus models, this requires touching
down with:
Achieving a wings-level touchdown (i.e., with no
decrab) would result in a 13-degree crab angle at
touchdown, potentially resulting in landing gear
damage ( point B ).
−
5 degrees of crab angle; and,
−
5 degrees of bank angle.
The decision to perform the flare with no decrab, with
partial decrab or with complete decrab should depend
upon the prevailing crosswind component but also on
the following factors (or as specified by company’
SOPs):
With 30 kt crosswind, adopting a combination of
sideslip and crab-angle (i.e., moving from point A to
point C ) restores significant margins relative to
geometry and roll / rudder limits while eliminating the
risk of landing gear damage). This requires, typically:
•
5 degrees of crab angle; and,
•
Wind gustiness;
•
5 degrees of bank angle,
•
Runway length;
•
Runway surface condition;
•
Type of aircraft; and,
•
Pilot experience on type.
On aircraft models limited by their geometry
characteristics, increasing the final approach speed
(i.e., by applying a wind correction on the final
approach speed, even under full crosswind, thus
moving from point A to point D ) increases the margin
with respect to the geometry limitation.
Crosswind Landings
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Touchdown – Friction Forces
Figure 4 illustrates these friction forces.
Assuming a crabbed-approach with no decrab or with
partial decrab during flare, upon touchdown the flight
should be on the up-wind side of the runway
centerline to ensure that the left and right main
landing gears are on their respective sides of
the runway centerline.
Aircraft motion
Crosswind
Upon touchdown of the main landing gear, the aircraft
transitions
from
the
“
laws
of
flight
dynamics “ to the “ laws of ground dynamics “.
Tire
cornering force
The following are among the events that occur upon
touchdown:
•
Wheel
rotation,
experienced.
unless
hydroplaning
is
Tire
braking force
Wheel rotation is the trigger for:
− Automatic ground spoilers extension;
Figure 4
− Autobrake operation; and,
− Anti-skid operation.
Wheels/tires-braking forces and tires-cornering
forces depend on the tire and runway conditions
but also on each other, the higher the braking
force, the lower the cornering force, as illustrated
by Figure 5.
To minimize the risk of hydroplaning and ensure
a positive spin up of wheels, it is recommended
to perform a firm touchdown when landing on
a contaminated runway.
Buildup of friction forces between the wheel tires
and the runway surface, under the combined
effect of:
Tire Braking and Cornering Forces
100
−
Wheels/tires-braking forces; and,
90
−
Tire-cornering forces.
80
Antiskid
Activation
70
60
Force ( % )
•
Braking Force
Cornering Force
50
40
30
20
10
0
0
5
Free rolling wheel
Photo credit : Sextant Avionics
8
10
15
20
25
30
Slip Ratio ( % )
Figure 5
Crosswind Landings
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Effect of Fuselage and Fin Side Force
Transient effects such as the distortion of the tire
thread ( caused by any yawing movement of the
wheel ) or the activation of the anti-skid system
affect the tire-cornering and wheel-braking forces (
in both magnitude and direction ) and, thus, affect
the overall balance of friction forces.
As the aircraft touches down, the side force created
by the crosswind component on the fuselage and fin
tends to make the aircraft skid sideways (downwind)
off the centerline, as illustrated by Figure 6.
As a consequence, the ideal balance of forces
illustrated by Figure 3 rarely is steadily
maintained during the initial landing roll.
Effect of Thrust Reversers
When selecting reverse thrust with some crab angle,
the reverse thrust results into two force components,
as illustrated by Figure 6:
Effect of Touchdown on Alignment
When touching down with some crab angle on a dry
runway, the aircraft automatically realigns with the
direction of travel down the runway.
•
A stopping force aligned along the aircraft
direction of travel (runway centerline); and,
•
A side force, perpendicular to the runway
centerline, which further increases the tendency
to skid sideways.
On a contaminated runway, the aircraft tends to
travel along the runway centerline with the existing
crab angle.
Crosswind
component
Touchdown
with partial
decrab
Aircraft
skidding
sideways
due to
fuselage/fin
side force
and reverse
thrust side
force
Reverse
cancelled
and brakes
released
Directional
control and
centerline
regained
Figure 6
Directional Control during Crosswind Landing
Crosswind Landings
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Maintaining / Regaining Directional Control
The thrust reverser effect decreases with decreasing
airspeed.
The higher the wheel/tire braking force, the lower the
tire-cornering force; therefore, if the aircraft tends to
skid
sideways,
releasing
the
brakes
(i.e., by taking over from the autobrake) increases the
tire-cornering and contributes to maintaining or
regaining directional control.
As airspeed decreases, the rudder efficiency
decreases and is further affected by the airflow
disruption created in the wake of the engine reverse
flow, possibly resulting in difficulties to maintain
directional control.
Selecting reverse idle cancels the effects of reverse
thrust (i.e., the side force and rudder airflow
disruption) and, thus, further assists in regaining
directional control.
Effect of Braking
In a high crosswind, cross-controls may have to be
maintained after touchdown to prevent the into-wind
wing from lifting and to counteract the weather-vane
effect (some flight crew training manuals adequately
state that the pilot should continue to fly the aircraft
during the landing roll ).
After directional control has been recovered and
the runway centerline has been regained:
However, into-wind aileron decreases the lift on the
into-wind wing, thus resulting in an increased load on
the into-wind landing gear.
Because the friction force increases as higher loads
are applied on the wheels and tires, the braking force
increases on the into-wind landing gear, creating an
additional tendency to turn into-wind, as illustrated by
Figure 7.
•
Pedal braking can be applied (autobrake was
previously disarmed when taking over) in a
symmetrical or differential manner, as required;
and,
•
Reverse thrust can be reselected.
Optimum Braking
Refer to Briefing Note 8.4 – Optimum Use of Braking
Devices.
When the runway contaminant is not evenly
distributed, the antiskid system may release
the brakes on one side only.
Factors Involved in Crosswind-Landing
Incidents and Accidents
The following factors often are involved in crosswindlanding incidents and accidents:
Figure 7
Effect of Uneven MLG Loads on Braking
•
Reluctance to recognize changes in landing data
over time (i.e., wind direction shift, wind velocity
or gust increase);
•
Failure to seek additional evidence to confirm the
initial
information
and
initial
options
(i.e., reluctance to change pre-established
plans);
•
Reluctance to divert to an airport with less
crosswind conditions;
•
Lack of time to observe, evaluate and control the
aircraft attitude and flight path in a highly
dynamic situation;
Crosswind Landings
Page 8
AIRBUS INDUSTRIE
Flight Operations Support
•
•
Getting to Grips with
Approach-and-Landing Accidents Reduction
Associated Briefing Notes
Difficulties with pitching effect of under-wingmounted engines in gusty conditions (i.e., headon gust effect on indicated airspeed and pitch
attitude); and,
The following Briefing Notes complement the above
information and provide a comprehensive overview of
landing techniques:
Ineffective differential braking due to the partial
release of the brake pedal (i.e., if the brake pedal
is only partially released, the braking demand
may still exceed the anti-skid regulated pressure
and, thus, still produce a symmetrical braking
action).
8.1 – Preventing Runway Excursions and
Overruns,
8.2 – The Final Approach Speed,
8.3 – Factors Affecting Landing Distances,
Summary of Key Points
8.4 – Optimum Use of Braking Devices,
Adherence to the following key points increases
safety during crosswind-landing operations:
8.5 – Landing on Wet and Contaminated
Runway,
•
•
Understand all applicable operating factors,
maximum recommended values and limitations;
8.6 – What’s Your Current Wind ?
Use recommended and published flying
techniques associated with crosswind landing;
Regulatory References
Note :
A wings-level touchdown (i.e., without any
decrab) may be safer than a steady-sideslip
touchdown with an excessive bank angle;
•
Request the assignment of a more favorable
runway, if prevailing runway conditions and
crosswind component are considered inadequate
for a safe landing;
•
Adapt the autopilot disconnect altitude to
prevailing conditions in order to have time to
establish manual control and trim the aircraft
(conventional aircraft models) before the align /
decrab phase and flare;
•
Be alert to detect changes in ATIS and tower
messages (i.e., wind direction shift, velocity
and/or gust increase); and,
•
Beware of small-scale local effects associated
with strong winds:
−
Updrafts and downdrafts;
−
Vortices created by buildings, forests or
terrain.
•
ICAO – Preparation of an Operations Manual
(Doc 9376).
•
JAR-OPS 1.1045 and associated Appendix 1,
2.1.(n) – Operations manual – structure and
contents.
Crosswind Landings
Page 9
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