Installation and Operation Manual
AA95-1000TSO
Single Channel Audio Controller
REVISION 1.01
IMPORTANT NOTICE
Chelton Avionics Inc. doing business as Cobham Aerospace
Communications is responsible for full distribution and revisions of ICA's (Instructions for Continued Airworthiness).
For inquiries regarding the content and currency of this manual contact Wulfsberg Electronics Division, 6400
Wilkinson Drive, Prescott, Arizona, 86301. Telephone (928)
756-1615 or refer to the following website: www.wulfsberg.com
for more information.
Copyright 2013
AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual
Prepared By: Ken Marshall Checked By: John Peterson Approved By: John Markham
REVISION RECORD
Revision
1.00
Date
Jul 10, 2013
1.01
DCA
W13194 Initial Release
W14157
Description
Updated Section 1.4.1 Lighting specifications to add NVIS
Backlighting specs.
Sept. 12, 2014
Rev 1.01 CONFIDENTIAL AND PROPRIETARY TO COBHAM Page ii
Section
1.
2.1
2.2
2.3
2.3.1
2.3.2
2.3.3
2.3.4
2.3.5
2.4
2.4.1
2.4.2
2.5
2.6
3.
1.1
1.2
1.3
1.4
1.4.1
1.4.2
1.4.3
1.4.4
2.
3.1
3.2
3.3
3.3.1
3.3.2
3.3.3
3.4
3.5
3.5.1
3.5.2
Title
AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual
Table of Contents
Description
Introduction
Product Description
Design Features
Specifications
Electrical Specifications
Physical Specifications
Environmental Specifications
Product Approval
Installation
Introduction
Airworthiness Limitations
Installation Procedures
Warnings
Cautions
Cabling and Wiring
Legend Installation
Post-Installation Checks
Adjustments and Connections
Left Side Panel Adjustments
Right Side Panel Adjustments
Accessories Required But Not Supplied
Installation Drawings
Operation
Introduction
General Information
Controls and Indicators
Receive Audio Select Switches
Transmit Selector Switch
ICS Functions
Emergency Operation
Audio Alerting Functions
Direct Audio
Internal Alerting
Rev 1.01 CONFIDENTIAL AND PROPRIETARY TO COBHAM Page iii
2-1
2-1
2-1
2-1
2-1
2-2
2-2
2-3
2-4
2-4
2-4
2-5
2-5
3-1
3-1
3-1
3-1
3-2
3-3
3-4
3-4
3-4
3-4
Page
1-1
1-1
1-1
1-2
1-2
1-3
1-3
1-4
AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual
1.1 Introduction
Information in this section consists of product description, design features and specifications for the
AA95-1000TSO Single Channel Audio Controller.
Review all notes, warnings and cautions.
1.2 Product Description
The AA95-1000TSO provides control for all aircraft audio, allowing selection of transmit and receive audio, LIVE, KEYED, or VOX intercom, interface for an additional hand-held transmit microphone (hand mic), and pilot isolation/emergency operation.
Transmit and PA functions are controlled with a single rotary switch. Receive audio and ICS operations are controlled with toggle switches. Receive volume, ICS volume and ICS VOX squelch are individually adjusted with rotary controls. Sidetone (S/T) level is adjustable internally.
1.3 Design Features
The AA95-1000TSO is a Dzus rail mounted unit with NVIS Green B lighted faceplate. Transceiver interfacing is accomplished through directly switched microphones. To ensure maximum radio compatibility, it has a ground referenced keyline that does not incorporate diodes or other steering components.
Independent control is provided for each audio channel within the controller, allowing sidetone, ICS audio, and RX audio to be independently set.
Boom mic support is provided for the pilot, co-pilot and rear pilot, with both ICS and XMIT functions via cyclic or yoke switching. Live (Hot Mic) and VOX ICS are also provided, designed to allow immediate transmission via this mode without further control panel switching, and immediate return to ICS operation on completion. The ICS (intercom) function is achieved using dynamic noise reduction and active filtering. This provides the clearest possible ICS audio under high ambient noise conditions by rejecting airframe and wind noise, and passing only voiceband information.
All audio, except the S/T of the radio in use and DIRECT AUDIO input signal, is muted during transmit for clarity. ICS operation allows transmit during any ICS mode by using the transmit PTT switch.
All external interconnects, switches and relay contacts are gold plated for maximum reliability. Switches and relays are sealed. Flame-retardant circuit boards are postcoated for maximum moisture resistance and corrosion prevention. Relays are sealed, high vibration rated (50g shock), dry nitrogen filled units.
The front panel is designed with removable legends allowing the installer to configure the panel top match functions of previous AA95 models. The unit backlighting is adjustable from 0-28VDC lighting bus installations. Both backlighting and indicator lighting is compatible with most NV IS “Green” cockpit environments.
Rev 1.01 CONFIDENTIAL AND PROPRIETARY TO COBHAM Page 1-1
AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual
1.4 Specifications
1.4.1 Electrical Specifications
Input Power
Lighting
Input Signals
Quantity
Audio level
Output Signals
Quantity
Impedance
Circuitry Type
Coupling
Keylines
Rated level:
Headset
Direct Audio
Alert
Impedance
27.5 Vdc Nominal
0.50 A max
27.5 Vdc @ <1 mA
Backlighting Color: NVIS Green B u'=0.131; v'=0.623; r=0.057,
Backlighting Luminance=1.0+/-0.5fL
Indicator Color: NVIS Green B u'=0.131; v'=0.623; r=0.057
Indicator Luminance: 15+/-5fL
11 receive channels
7 mic channels
1 ICS tie channel
1 direct channel
2.5 Vrms for receiver inputs
0.25 Vrms for mic inputs
0.34 Vrms for ICS tie input
2.5 Vrms for direct audio inputs
1 k
10% for receive inputs
100
10% for mic inputs
1.6 k
10% for ICS tie input
1.3 k
10% for Direct Audio input
All are single ended inputs
<-60 dB
Pilot & copilot transmit PTT
Rear hand mic transmit PTT
Pilot & copilot ICS PTT
2 Alerts - active low
1 Call Switch Output with Chime
1 Call/ISO Indicator Input
6 Headset outputs
6 Transmitter mic outputs
5 Transmitter keyline outputs
7.7 Vrms or 100 mW (20 dBm) into 600
10 mW (10 dBm) into 600
90 mVrms
10% into 600
20
max
Rev 1.01 CONFIDENTIAL AND PROPRIETARY TO COBHAM Page 1-2
Circuitry Type
AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual
Balanced headset outputs for high common mode noise rejection
Frequency Response:
Sidetone
Receive inputs
Intercom
Distortion
Audio Noise Level
Coupling
Alert 1
Alert 2
Call Chime
Output Regulation at 400% and
75% of rated load.
Annunciators
<3 dB from 350 Hz to 6000 Hz
<3 dB from 350 Hz to 6000 Hz
<3 dB from 350 Hz to 3000 Hz
1.5 kHz
20%
Same as Alert 1 but swept @ 2 cycles/sec
Approximately the same as Alert 2 but on for 2 sec
<10% THD @ rated power output
>60 dB down from rated output (without signal)
<-55 dB
<10% distortion /
3 dB max of rated output power
Green LED will light for transmit operation
Green LED will light for CALL or ISO operation
1.4.2
Height
Depth
Width (behind panel)
Weight
Physical Specifications
Mounting
Faceplate
Material/Finish
Connectors
1.88" (47.6 mm)
6.83" (173.4 mm)
4.99" (126.7 mm)
2.1 lbs. (955 g)
Dzus rail
Engraved acrylic edge lit panel
Chassis & cover are 5052-H32 brushed aluminum with chromate conversion finish
Male 50 pin & 37 pin D-submin with slide locks
1.4.3 Environmental Specifications
Operating Temperatures
Survival Temperatures
Altitude
Humidity
Shock
Vibration
-20
C to +55
C
-55
C to +85
C
25,000 ft. Max
95%
6g (any axis)
RTCA/DO-160C Categories P and S
Qualification of the AA95-1000TSO Single Channel Audio Controller was completed in accordance with DO-160A Env. Cat. A1B1/A/PS/XXXXXXABABA
Rev 1.01 CONFIDENTIAL AND PROPRIETARY TO COBHAM Page 1-3
1.4.4
AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual
Product Approval
FAA: TSO-C50c (RTCA/DO-170 Class I a, RTCA/DO-160 A & C)
Section 1 ends
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AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual
Section 2 Installation
2.1 Introduction
Information in this section consists of unpacking and inspection procedures, installation procedures, postinstallation checks and installation drawings for the AA95-1000TSO Single Channel Audio Controller.
Review all notes, warnings and cautions.
2.2 Airworthiness Limitations
The Airworthiness Limitations Section is FAA approved and specifies maintenance required under 14
CFR §§ 43.16 and 91.403 of the Federal Aviation Regulations unless an alternative program has been
FAA approved.
There are no new (or additional) airworthiness limitations associated with this equipment and/or installation.
Maintenance of the AA95-1000TSO Single Channel Audio Controller is ‘on condition’ only. Periodic maintenance of this product is not required.
2.3 Installation Procedures
2.3.1 Warnings
WARNING:
High volume settings can cause hearing damage.
Set the headset volume control to the minimum volume setting prior to conducting tests, and slowly increase the headset volume to a comfortable listening level.
2.3.2 Cautions
CAUTION:
Do not bundle any lines from this unit with transmitter coax feed lines. Do not bundle any logic, audio, or DC power lines from this unit with 400 Hz synchro wiring or AC power lines. Do not position this unit next to any device with a strong alternating magnetic field such as an inverter, motor or blower, or significant audio interference will result.
In all installations, use shielded cable exactly as shown, and ground only as indicated. Significant problems may result from not following these guidelines.
Failure to follow the installation and wiring instructions provided in this manual for power and ground connections, including the rating of the circuit breaker, may lead to damage in the power input circuitry of the unit.
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AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual
2.3.3 Cabling and Wiring
All wire shall be selected in accordance with the original aircraft manufacturer's Maintenance Instructions or AC43.13-1B Change 1, Paragraphs 11-76 through 11-78. Unshielded wire types shall qualify to
MIL-W-22759 as specified in AC43.13-1B Change 1, Paragraphs 11-85, 11-86, and listed in Table 11-11.
For shielded wire applications, use Tefzel MIL-C-27500 shielded wire with solder sleeves (for shield terminations) to make the most compact and easily terminated interconnect. Follow the interconnect drawing in Section 2.7 as required.
Allow 3" from the end of the shielded wiring to the shield termination to allow the connector hood to be easily installed. Refer to the interconnect drawing in Section 2.7 for shield termination details. Note that the hood is a "clamshell" hood, and is installed after the wiring is complete. Aircraft harnessing shall permit the unit to be removed from the panel for easy access to all side adjustments. Do NOT mount the unit until all adjustments have been performed.
Maintain wire segregation and route wiring in accordance with the original aircraft manufacturers
Maintenance Instructions.
Unless otherwise noted, all wiring shall be a minimum of 22 AWG, except power and ground lines, which shall be a minimum of 20 AWG. Reference the Interconnect drawing for additional specifications. Check that the ground connection is clean and well secured, and that it shares no path with any electrically noisy aircraft accessories such as blowers, turn and bank instruments or similar loads. Power to this unit must be supplied from a separate circuit breaker or fuse (fast blow), and not attached to any other circuit breaker without additional protection. Verify that the selected circuit breaker size and wire gauge are adequate for the installation using the techniques specified in AC43.13-1B Change 1, Paragraphs 11-47 through 11-51 and 11-66 through 11-69.
2.3.4 Legend Installation
Custom removable legends are to be ordered and installed by the customer.
Each AA95-1000TSO requires a set of legends, either purchased individually (Part no. 55-08-xxxx, where xxxx is the description of the legend, e.g., “COM1”) or as a legend kit (Part no. AA95LK-xxx). Each kit consists of a number of printed legends and blanks (to suit customer requirements), and each legend comes complete with a black gasket, either attached or loose in the bag.
When installing the legends for the first time, each legend must be fitted
Legend Gasket with a black gasket to ensure uniformity of legend lighting. The gasket fits into place on the back of the legend, but is easily dislodged or damaged. Take particular care to ensure that it is properly positioned before snapping the legend fully into place. If a replacement gasket is required, the whole legend must be ordered.
If it is necessary to remove or replace a legend, carefully lever the legend away from the faceplate, and insert the new or replacement legend as described above.
CAUTION
If the faceplate is damaged in any way during this process, light leakage may occur, which will necessitate returning the unit to the manufacturer for repair or replacement.
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AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual
2.3.5 Post-Installation Checks
Perform any required adjustments of preset levels, and ensure that the audio controller is properly mounted and secured prior to flight.
2.3.5.1 Voltage/Resistance Checks
Do not attach the AA95-1000TSO until the following conditions are met.
Check the following: a) b) c)
P101 pins
P101 pin <34> for continuity to ground (below 0.5
).
P102 pin
<16>
<19> and <17> for +28 Vdc relative to ground.
for +28 Vdc lights bus voltage. d) Check all Mic, phone, music and key lines for shorts to ground or adjacent pins.
2.3.5.2 Power On Checks
Power up the aircraft’s systems and confirm normal operation of all functions of the AA95-1000TSO.
Refer to Section 3 (Operation) for specific operational details. a) Start with only the pilot's headset installed. Check for correct ICS, radio, and transmit operation. Do not proceed until the radios are functioning correctly. The S/T (sidetone) trimpot accessible through the left side of the controller and the transceiver internal trimpot may have to be adjusted for correct balance for the pilot. Adjustment of the individual radio
RX levels should be set first, and then the front panel RX master volume control. b) Unusual buzzes, hums or other background audio are symptomatic of multiple grounds or noisy external systems sharing the same wire bundle. Note that incorrect jack wiring is a common fault, especially for passenger stations, and may cause loss of audio, a tone on the headset lines, or other problems. Failure to key or correctly modulate a transceiver may be caused by missing grounds on the radio or audio controller. c) Plug in the hand mic and test for correct operation. Note that wiring faults for this accessory may cause peculiar loss of ICS or TX functions because it has over-riding priority in the system. d) Plug in the remaining headsets and check for proper operation. Note that an incorrect drop cord or improper jack wiring may cause a wide range of problems from loss of audio to a tone heard in the headset. e) To verify proper operation, all functions and levels should be checked in-flight. f) Check that preset adjustments are completed before aircraft departure.
Upon satisfactory completion of all performance checks, make all required log book entries, electrical load, weight and balance amendments and other documentation as required by your local regulatory agency before releasing the aircraft for service.
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AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual
Adjustments and Connections 2.4
The unit ships from the factory with all internal adjustments set to the normal test levels. Once installed in the aircraft, it may be desirable to change some of these settings to best suit the local operating environment. The internal adjustments are located on the sides of the unit and are as follows:
2.4.1 Left Side Panel Adjustments
The trimpots on the left side panel are used to adjust the levels of audio in the user’s headphones.
Rotating the trimpots cw increases the level, and ccw reduces it.
The ALERT LEVEL trimpot is used to adjust the levels for the three internally generated Alert signals.
Other parameters relating to these signals are adjusted from the right side panel (see section 2.5.2.)
The S/T LEVEL trimpot adjusts the internal gain of the sidetone of the selected transceiver (from the front panel) in the user’s headphones.
The VOX LEVEL trimpot sets the sensitivity level for the front panel VOX control (the level of audio required to activate microphones).
The POWER ON LED will illuminate to indicate that the unit is connected to the power supply.
2.4.2 Right Side Panel Adjustments
A variety of different signals can be selected to trigger the internal Alert signals. The trimpots on the right side panel are used to adjust the characteristics of the audible signals that the user will hear.
Audio Alert 1 is a single tone signal and Audio Alert 2 and the call chime are two tone signals. The pitch of the signals can be adjusted using the relevant TONE trimpot, and the cycling rate of the two-tone signals can be adjusted using the RATE trimpots. The duration of the call chime can be adjusted from one to three seconds using the TIME trimpot.
The DIR AUD LEVEL trimpot is used to adjust the audio level of the devices connected to the DIR AUD input.
Rev 1.01 CONFIDENTIAL AND PROPRIETARY TO COBHAM Page 2-4
AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual
2.5 Accessories Required But Not Supplied
Installation kit p/n D50S37SL-IKC (crimp) is required to complete the installation. The kit consists of the following:
Quantity
1
Description
50 Pin D-min Female Crimp Kit
COBHAM Part No.
D50SL-IKC
1
D50SL IKC consists of:
37 Pin D-min Female Crimp Kit D37SL-IKC
Quantity
1
50
1*
1*
1
Description
D-min 50 Socket Housing
MS Crimp Socket
Jack Screw Set
Lock Clip Set
50 Pin Connector Hood
COBHAM No.
20-21-050
20-26-901
20-27-002
20-27-004
20-29-051
D37SL-IKC consists of:
Quantity
1
37
1*
1*
1
* Use as required.
Installation Drawings
Description
D-min 37 Socket Housing
MS Crimp Socket
Jack Screw Set
Lock Clip Set
37 Pin Connector Hood
COBHAM No.
20-21-037
20-26-901
20-27-002
20-27-004
20-29-038
2.6
DRAWING REV. DESCRIPTION TYPE
AA95-1000TSO-403-0
AA95-1000TSO-405-0
1.01 Audio Controller
1.01 Audio Controller
Interconnect
Connector Map
AA95-1000TSO-905-0 1.00 Single Channel Audio Controller Faceplate
AA95-1000TSO-922-0 1.01 Audio Controller Mech. Installation
Section 2 ends following the above documents
SERIAL No.
All
All
All
All
Rev 1.01 CONFIDENTIAL AND PROPRIETARY TO COBHAM Page 2-5
AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual
Section 3 Operation
3.1 Introduction
Information in this section consists of functional and operational procedures for the AA95-1000TSO
Single Channel Audio Controller.
3.2 General Information
The AA95-1000TSO provides control for all aircraft audio, allowing selection of transmit and receive audio, LIVE, KEYED, or VOX intercom, interface for an additional hand held transmit microphone (hand mic), and pilot isolation/emergency operation.
Sidetone level is adjustable internally, and receive (RX) and intercom (ICS) levels are adjustable on the front panel. All audio, except the sidetone of the radio in use and the directly connected DIRECT AUDIO input signal (see Section 3.5.1), is muted during transmit for clarity. ICS operation allows transmit during any ICS mode by using the PTT switch.
3.3 Controls and Indicators
All transmit functions are controlled with a single rotary selector switch. Receive audio and ICS operations are controlled with color-coded toggle switches. Receive volume, ICS volume and ICS VOX squelch are individually adjusted with rotary controls.
3.3.1 Receive Audio Select Switches
The transceiver receive audio select switches (white switch bats) are two position switches. When set to the up position, the respective transceiver receive audio is selected on. When set to the down position, the respective transceiver receive audio is selected off.
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AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual
When the Patient Phones ON/OFF switch is placed in the OFF position, the PAT Phones output is disconnected. This is normally used when a PAX station is connected to a user whom the installer wishes to have controlled access to the interphone system, such as an airlifted patient on board an air medical aircraft who should not hear all interphone communications. However, the PAT phones output can be used for any PAX user if the PAT switch is left on.
When the CALL/ISO input to the AA95-1000TSO is grounded, the CALL/ISO indicator LED will light. When the
CALL button is pressed, the call chime will activate and a CALL switch connection from the AA95-1000TSO to another AA95-1000TSO CALL/ISO input will cause the CALL/ISO indicator LED to illuminate.
The NAV receive audio select switches (blue switch bats) are three position switches. When set to the up or down position, the respective NAV receive audio is selected on. When set to the center off position, the respective NAV receive audio is selected off.
The master receive volume control (RX VOL) adjusts all receive audio concurrently from 1% to full. It is important to set the individual radio volume controls to a nominal level, then use the master receive volume on the audio controller to adjust for changing flight conditions.
When the red mode switch is set to NORMAL, the passengers will hear the radio audio as selected on the controller. The passengers will not hear any radio audio when the red mode switch is in the ISO/EMR position.
3.3.2 Transmit Selector Switch
The transmit selector switch is a six position switch used to select the desired transceiver. When the hand mic or transmit PTT switch is activated, the mic will be coupled to the radio selected. The pilot has priority over the copilot during transmit operations.
Receive audio for the transceiver selected is automatically activated as a function of the rotary selector switch, and no additional switching is needed to establish outside communication. During transmit, all audio selected is muted except the sidetone of the transceiver in use.
The front panel TX indicator will illuminate green when either the pilot or co-pilot transmits.
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3.3.3
AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual
ICS Functions
3.3.3.1 ICS Modes
Intercom audio may be implemented in three modes: LIVE (on constantly), VOX (voice activated), or
KEYED (active only when switched by ICS PTT switch). It is common to use the LIVE mode during ground operations, startup, etc. and to use VOX or KEYED operation if conditions are so noisy that ‘pilot fatigue’ will result.
LIVE (Hot Mic Operation)
ICS mode switch (orange switch bat) set to the up (VOX) position and the VOX squelch control set to the full counter-clockwise position.
KEYED ICS (PTT Operation)
ICS toggle switch (orange switch bat) set to the down (KEY) position. Keyed ICS is inherent to the pilot and copilot microphone circuits only.
VOX (Voice Activated)
ICS toggle switch (orange switch bat) set to the up (VOX) position. Set the ICS VOX Squelch control fully counter-clockwise and then slowly rotate clockwise until the intercom just becomes quiet. This setting will vary with ambient noise conditions, and the quality and number of microphones connected in the system.
3.3.3.2 General ICS Functions
Passenger ICS audio is LIVE when the controller is in the LIVE or KEYED mode of ICS operation. It is
VOX triggered when that mode is selected. The passengers are always LIVE unless interrupted by an inline PTT cord, or if the controller is set for VOX operation. Passenger and observer (copilot) operations can be optimized by using in-line PTT type cord assemblies designed for use with NAT audio controllers.
All ICS audio is controlled by the front panel ICS volume control and may be varied to suit conditions.
The ICS VOL control provides adjustment from approximately 1% to full output.
The mode switch (red switch bat) is used to select between NORMAL and PILOT ISO/EMR modes. In the NORMAL position (down), all operations of the ICS are functional as described above. When the switch is in the pilot isolate/emergency position (PILOT ISO/EMR), the pilot is isolated from the rest of the
Rev 1.01 CONFIDENTIAL AND PROPRIETARY TO COBHAM Page 3-3
AA95-1000TSO Single Channel Audio Controller
Installation and Operation Manual passengers. If the controller is operated in the ISO/EMR mode, ICS operation will continue (if there is no fault condition) between the passengers and copilot, but will exclude the pilot. See section 3.4 for further details.
3.4 Emergency Operation
When the red PILOT ISO/EMR NORMAL mode switch is set to the ISO/EMR position, the pilot is removed from the ICS bus and connected directly to the selected radios. This mode should be selected in the event of a box fault or power failure.
In the ISO/EMR mode, all functions are retained by the pilot, except ICS and possibly boom mic operation. If the box or airframe fault prevents the TX annunciator from lighting during transmit (indicating a failure in the mic keying circuit), then the hand mic should be used. A power fault of any kind will prevent the TX annunciator from lighting, giving an immediate indication of failure. If ICS audio is still available, then the power to the controller has not failed, and loss of the TX light indicates TX switch failure.
In the ISO/EMR mode, all switches work exactly as they do during NORMAL operation, except for the RX and ICS volume controls, which have no effect.
The ISO/EMR function should be tested prior to flight to ensure proper operation, and allow the radio levels to be set adequately for emergency operation.
Any selected receive audio is switched to the primary user (pilot) in the ‘emergency’ mode, but not to any passengers in the system. Audio level will be lower than in NORMAL operation because the signals are obtained directly from the radios, bypassing the electronics in the controller. This is provided for failure situations that make operation impossible in the NORMAL mode (i.e., loss of power or amplifier failure, etc.)
3.5 Audio Alerting Functions
Two types of audio alerting are supported in the AA95-1000TSO: Direct Audio and Internal Alerting. The use of these alerting features should be determined, defined and recorded so that the operator has an opportunity to use these features as they were intended for their specific installation.
3.5.1 Direct Audio
Direct Audio is when an audio signal from an existing warning system is connected ‘directly’ into the audio system, and is not front panel selectable. There is one Direct Audio input on the AA95-1000TSO. Direct
Audio is amplified/adjustable and is connected directly to the pilot's headset output.
3.5.2 Internal Alerting
Internal Alerting is provided by three separate, internal tone generators that are coupled to the headset output. These tones are a function of the AA95-1000TSO itself, and can be used to supplement existing warning tones (Low Rotor, Engine Out warnings) or provide unique alerting capability for functions such as ICS Call, Radar Altimeter DH warning, etc. The internal alerts and how they will be used, are determined at the time of installation and are not front panel selectable.
Section 3 ends
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