TM-55-1520-234-10

TM-55-1520-234-10
TM 55-1520-234-10
TECHNICAL MANUAL
OPERATORS MANUAL
ARMY MODEL AH-LS (MOD) HELICOPTER
This copy is a reprint which includes
current pages from Changes 1-31.
HEADQUARTERS, DEPARTMENT OF THE ARMY
17 NOVEMBER 1976
TM 55-1520-234-10
TM 55-1520-234-10 is published for the use of all concerned.
By Order of the Secretary of the Army:
Official:
PAUL T. SMITH
Major General, United States Army
The Adjutant General
BERNARD W. ROGERS
General, United States Army
Chief of Staff
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31 (qty rqr block No. 271) Operator Maintenance Requirements
for AH-1S Helicopter.
TM 55-1520-234-10
URGENT
NOTICE:
THIS CHANGE HAS BEEN PRINTED AND DISTRIBUTED OUT OF SEQUENCE.
IT SHOULD BE
INSERTED IN THE MANUAL AND USED. UPON RECEIPT OF THE EARLIER SEQUENCED CHANGE
ENSURE A MORE CURRENT CHANGE PAGE IS NOT REPLACED WITH A LESS CURRENT PAGE.
TM 55-1520-234-10
C 31
CHANGE
NO. 31
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 23 April 1991
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a pointing hand.
Remove pages
Insert pages
4-37 and 4-38
4-37 and 4-38
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
CARLE. VUONO
General, United States Army
Chief of Staff
Official:
PATRICIA P. HICKERSON
Colonel, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31-E, block No. 0149, -10 and CL maintenance requirements
for TM 55-1520-234-10.
URGENT
TM 55-1520-234-10
C 30
CHANGE
NO. 30
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 29 March 1994
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a pointing hand.
Remove page
Insert pages
c/d
2-5 and 2-6
2-13 through 2-20
2-23 through 2-28
2-29 through 2-32
3-15 and 3-16
4-1 and 4-2
4-19 and 4-20
4-23 and 4-24
4-27 and 4-28
4-35 and 4-34
4-34.1/4-34.2
4-35 and 4-36
5-3 through 5-6
6-1 and 6-2
6-5 and 6-6
6-15 and 6-16
7-3 and 7-4
7-9 and 7-10
7-10A/7-10B
7-15 and 7-16
7-49 and 7-50
8-1 and 8-2
8-5 through 8-12
8-17 and 8-18
9-5 through 9-8
9-9 and 9-10
9-11/9-12
A-1 and A-2
Index 1 through Index 4
c/d
2-5 and 2-6
2-13 through 2-20
2-23 through 2-28
2-29 through 2-32
3-15 and 3-16
4-1 and 4-2
4-19 and 4-20
4-23 and 4-24
4-27 and 4-28
4-33 and 4-34
4-34.1/4-34.2
4-35 and 4-36
5-3 through 5-6
6-1 and 6-2
6-5 and 6-6
6-15 and 6-16
7-3 and 7-4
7-9 and 7-10
7-10A/7-10B
7-15 and 7-16
7-49 and 7-50
8-1 and 8-2
8-5 through 8-12
8-17 and 8-18
9-5 through 9-8
9-9 and 9-10
9-11/9-12
A-1 and A-2
Index 1 through Index 4
DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.
TM 55-1520-234-10
C 30
2. Retain this sheet in front of manual for reference purposes.3
By Order of the Secretary of the Army:
GORDON R. SULLIVAN
General, United States Army
Chief of Staff
Official:
MILTON H. HAMILTON
Administrative Assistant to the
Secretary of the Army
02649
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31-E, block No. 0149, requirements for TM 55-1520-234-10.
TM 55-1520-234-10
C 29
URGENT
CHANGE
NO. 29
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 5 October 1990
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a pointing hand.
Remove pages
Insert pages
9-1 and 9-2
9-1 and 9-2
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
CARL E. VUONO
General, United States Army
Chief of Staff
Official:
THOMAS F. SIKORA
Brigadier General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, -10 and CL Maintenance requirements for AH-1S
Helicopter, Attack.
URGENT
TM 55-1520-234-10
C 28
URGENT
CHANGE
NO. 28
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 27 June 1990
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a pointing hand.
Remove pages
Insert pages
5-5 and 5-6
5-5 and 5-6
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
CARL E. VUONO
General, United States Army
Chief of Staff
Official:
WILLIAM J. MEEHAN II
Brigadier General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, -10 and CL Maintenance requirements for AH-1S
Helicopter, Attack.
URGENT
TM 55-1520-234-10
C 27
URGENT
CHANGE
NO. 27
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 30 August 1989
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a pointing hand.
Remove pages
Insert pages
5-5 and 5-6
5-5 and 5-6
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
CARL E. VUONO
General, United States Army
Chief of Staff
Official:
WILLIAM J. MEEHAN II
Brigadier General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, -10 and CL Maintenance requirements for AH-1S
Helicopter, Attack.
URGENT
TM 55-1520-234-10
C 26
URGENT
CHANGE
NO. 26
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 24 August 1989
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a pointing hand.
.
Remove pages
Insert pages
4-33 and 4-34
---4-35 and 4-36
4-33 and 4-34
4-34.1/4-34.2
4-35 and 4-36
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
CARL E. VUONO
General, United States Army
Chief of Staff
Official:
WILLIAM J. MEEHAN 11
Brigadier General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, -10 and CL Maintenance requirements for AH-1S
Helicopter, Attack.
URGENT
TM 55-1520-234-10
C 25
URGENT
CHANGE
NO. 25
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 31 MAY 1989
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a miniature pointing hand.
Remove pages
Insert pages
3-15 and 3-16
3-17 and 3-18
3-15 and 3-16
3-17 and 3-18
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
CARL E. VUONO
General, United States Army
Chief of Staff
Official:
WILLIAM J. MEEHAN II
Brigadier General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, -10 and CL Maintenance requirements for AH-1S
Helicopter, Attack
URGENT
TM 55-1520-234-10
C 24
URGENT
CHANGE
NO. 24
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 13 April 1989
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a miniature pointing hand.
Remove pages
Insert pages
9-5 and 9-6
9-5 and 9-6
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
CARL E. VUONO
General, United States Army
Chief of Staff
Official:
WILLIAM J. MEEHAN II
Brigadier General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, -10 and CL Maintenance requirements for AH-1S
Helicopter, Attack.
URGENT
TM 55-1520-234-10
C 23
URGENT
CHANGE
NO. 23
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 6 February 1989
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a miniature pointing hand.
Remove pages
Insert pages
8-5 and 8-6
8-5 and 8-6
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
CARL E. VUONO
General, United States Army
Chief of Staff
Official:
WILLIAM J. MEEHAN II
Brigadier General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, -10 and CL Maintenance requirements for AH-1S
Helicopter, Attack.
URGENT
TM 55-1520-234-10
C 22
URGENT
CHANGE
NO. 22
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 19 July 1988
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a miniature pointing hand.
Remove pages
Insert pages
9-1 and 9-2
9-1 and 9-2
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
CARL E. VUONO
General, United States Army
Chief of Staff
Official:
R. L. DILWORTH
Brigadier General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, -10 and CL Maintenance requirements for AH-1S
Helicopter, Attack.
URGENT
TM 55-1520-234-10
C 21
URGENT
CHANGE
NO. 21
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 17 May 1988
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a miniature pointing hand.
Remove pages
Insert pages
8-3 and 8-4
8-7 through 8-12
---
8-3 and 8-4
8-7 through 8-12
8-12A/8-12B
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
CARL E. VUONO,
General, United States Army
Chief of Staff
Official:
R. L. DILWORTH
Brigadier General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, -10 and CL Maintenance requirements for AH-1S
Helicopter, Attack.
URGENT
TM 55-1520-234-10
C 20
URGENT
CHANGE
No. 20
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 6 November 1987
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a miniature pointing hand.
Remove pages
Insert pages
---
4-28A/4-28B
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
CARL E. VUONO
General, United States Army
Chief of Staff
Official:
R. L. DILWORTH
Brigadier General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, -10 and CL requirements for AH-1S Helicopter, Attack.
URGENT
CHANGE
No. 19
TM 55-1520-234-10
C 19
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 30 September 1987
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1.
Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar
in the margin. An illustration change is indicated by a miniature pointing hand.
Remove pages
Insert pages
a through c/d
i and ii
1-1 and 1-2
2-3 through 2-8
2-13 and 2-14
2-17 through 2-20
2-23 through 2-28
--2-31 through 2-34
2-34A and 2-34B
2-35 and 2-36
2-36A/2-36B
2-37 through 2-39/2-40
3-17 and 3-18
4-27 through 4-30
4-35 and 4-36
4-39 and 4-40
5-1 through 5-6
5-6A and 5-6B
5-7 through 5-9/5-10
6-1
6-4
6-5 and-6-6
6-10N through 6-10T
6-15 through 6-20
7-1 and 7-2
7-5 and 7-6
7-7 and 7-8
7-9 and 7-10
----7-15 and 7-16
8-1 through 8-28
9-1 through 9-15/9-16
A-1 and A-2
Index 1 through Index 8
a through c/d
i and ii
1-1 and 1-2
2-3 through 2-8
2-13 and 2-14
2-17 through 2-20
2-23 through 2-28
2-28A/2-28B
2-31 through 2-34
2-34A and 2-34B
2-35 and 2-36
2-37 and 2-38
3-17 and 3-18
4-27 through 4-30
4-35 and 4-36
4-39 and 4-40
5-1 through 5-6
5-7 and 5-8
6-1 and 6-2
6-4
6-5 and 6-6
6-10N through 6-10T
6-15 and 6-16
7-1 and 7-2
7-5
7-8
7-9 and 7-10
7-10A/7-10B
7-14A and 7-14B
7-15 and 7-16
8-1 through 8-19/8-20
9-1 through 9-11/9-12
A-1 and A-2
Index 1 through Index 4
TM 55-1520-234-10
C 19
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
Official:
CARL E. VUONO
General, United States Army
Chief of Staff
R. L. DILWORTH
Brigadier General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, -10 and CL requirements for AH-1S Helicopter, Attack.
TM 55-1520-234-10
C 18
URGENT
CHANGE
NO. 18
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 30 June 1986
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICO?TER
TM 55-1520-234-10, 17 November 1976,.is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a miniature pointing hand.
Remove pages
Insert pages
5-1 and 5-2
9-12A/9-12B
9-13 and 9-14
5-1 and 5-2
9-12A/9-12B
9-13 and 9-14
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
JOHN A. WICKHAM, JR.
General, United States Army
Chief of Staff
Official:
R. L. DILWORTH
Brigadier General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, Operator Maintenance Requirements for AH-1S (MOD)
aircraft.
URGENT
TM 55-1520-234-10
C 17
CHANGE
NO. 17
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 9 August 1984
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a miniature pointing hand.
Remove pages
---
Insert pages
5-6A and 5-6B
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
Official:
JOHN A. WICKHAM, JR.
General, United States Army
Chief of Staff
ROBERT M. JOYCE
Major General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, Operator Maintenance Requirements for AH-1S (MOD)
aircraft.
TM 55-1520-234-10
C 16
URGENT
CHANGE
NO. 16
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 13 July 1984
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below. New or changed text material is indicated by a vertical bar in the
margin. An illustration change is indicated by a miniature pointing hand.
Remove Pages
Insert Pages
5-5 through 5-8
8-21 and 8-22
8-22A/8-22B
9-3 and 9-4
9-9 and 9-10
5-5 through 5-8
8-21 and 8-22
8-22A and 8-22B
9-3 and 9-4
9-9 and 9-10
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
JOHN A. WICKHAM, JR.
General, United States Army
Chief of Staff
Official:
ROBERT M. JOYCE
Major General, United State Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, Operator Maintenance Requirements for AH-1S (MOD)
aircraft.
URGENT
TM 55-1520-234-10
C 15
CHANGE
NO. 15
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 7 May 1984
}
Operator's Manual
ARMY MODEL AH-1 (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as Indicated below.
Chapter 2
Chapter 4
Chapter 5
Chapter 6
Chapter 8
Chapter 9
Remove Pages
2-1 thru 2-4
2-15 thru 2-18
2-23 and 2-24
2-29 and 2-30
2-34A and 2-34B
4-3 and 4-4
4-29 and 4-30
5-1 thru 5-6A/5-6B
6-1 thru 6-4
6-11 and 6-12
6-17 thru 6-20
8-7 and 8-8
8-9 thru 8-12
8-15 and 8-16
9-5 thru 9-8
9-11 thru 9-12A/9-12B
9-13 thru 9-15/9-16
Insert Pages
2-1 thru 2-4
2-15 thru 2-18
2-23 and 2-24
2-29 and 2-30
2-34A and 2-34B
4-3 and 4-4
4-29 and 4-30
5-1 thru 5-6B
6-1 thru 6-4
6-11 and 6-12
6-17 thru 6-20
8-7 thru 8-8A/8-8B
8-9 thru 8-12
8-15 and 8-16
9-5 thru 9-8A/9-8B
9-11 thru 9-12A/9-12B
9-13 thru 9-15/9-16
2. New or changed text material is indicated by a vertical bar in the margin. An illustration change is indicated by a
miniature pointing hand.
3. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
Official:
JOHN A. WICKHAM, JR.
General, United States Army
Chief of Staff
ROBERT M. JOYCE
Major General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, Operator Maintenance Requirements for AH-1S (MOD)
aircraft.
TM 55-1520-234-10
C 14
CHANGE
NO.14
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 25 August 1982
}
Operator's Manual
ARMY MODEL AH-LS (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below:
Chapter 2
Chapter 4
Chapter 5
Chapter 8
Remove Pages
Insert Pages
2-5 thru 2-8
2-10
2-13 and 2-14
2-27 thru 2-32
4-1 thru 4-2B
5-1 and 5-2
8-3 and 8-4
2-5 thru 2-8
2-10
2-13 and 2-14
2-27 thru 2-32
4-1 thru 4-2B
5-1 and 5-2
8-3 and 8-4
8-4A/8-4B
8-7 thru 8-10
8-7 thru 8-10
2. New or changed text material is indicated by a vertical bar in the margin. An illustration change is indicated by a
miniature pointing hand.
3. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
Official:
E. C. MEYER
General, United States Army
Chief of Staff
ROBERT M. JOYCE
Major General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, Operator Maintenance Requirements for AH-1S (MOD)
aircraft.
TM 55-1520-234-10
C 13
CHANGE
NO. 13
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 5 February 1982
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below:
Chapter 2
Remove pages
Insert pages
2-33 thru 2-34A/B
2-33 thru 2-34B
2-36A/2-36B
2. New or changed text material is indicated by a vertical bar in the margin. An illustration change is indicated by a
miniature pointing hand.
3. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
Official:
E. C. MEYER
General, United States Army
Chief of Staff
ROBERT M. JOYCE
Brigadier General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, Operator Maintenance Requirements for AH-1S (MOD)
aircraft.
TM 55-1520-234-10
C 12
CHANGE
No. 12
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 14 April 1981
}
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below.
Chapter 8
Remove pages
Insert pages
8-5 and 8-6
8-5 and 8-6
2. New or changed text material is indicated by a vertical bar in the margin. An illustration change is indicated by a
miniature pointing hand.
3. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
Official:
E. C. MEYER
General, United States Army
Chief of Staff
J. C. PENNINGTON
Major General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, Operator Maintenance requirements for AH-1S (MOD) aircraft.
TM 55-1520-234-10
C 10
URGENT
CHANGE
No. 10
}
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 28 March 1980
Operator's Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Remove and insert pages as indicated below.
Chapter 8
Remove pages
Insert pages
8-9 and 8-10
8-9 and 8-10
2. New or changed text material is indicated by a vertical bar in the margin. An illustration change is indicated by a
miniature pointing hand.
3. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
E. C. MEYER
General, United States Army
Chief of Staff
Official:
J. C. PENNINGTON
Major General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, Operator Maintenance requirements for AH-1S (MOD) aircraft.
URGENT
TM 55-1520-234-10
C9
CHANGE
No. 9
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 12 December 1979
}
Operators Manual
ARMY MODEL AH-1S (MOD) HELICOPTER
TM 55-1520-234-10, 17 November 1976, is changed as follows:
1. Warning Page is superseded as follows.
2. Remove and insert pages as indicated below.
Remove pages
Insert pages
Chapter 2
2-3 and 2-4
2-10 thru 2-14
2-17 thru 2-20
2-23 and 2-34
2-35 and 2-36
2-39/2-40
2-3 and 2-4
2-10 thru 2-14
2-17 thru 2-20
2-23 thru 2-34A/2-34B
2-35 and 2-36
2-39/2-40
Chapter 3
3-1 and 3-2
3-3 and 3-4
3-11 and 3-12
3-15 thru 3-17/3-18
3-1 and 3-2
3-4
3-11 and 3-12
3-15 thru 3-18
Chapter 4
4-1 thru 4-2A/4-2B
4-3 and 4-4
4-11 and 4-12
4-15 thru 4-18
4-19 thru 4-24
4-27 and 4-28
4-29 thru 4-38
5-1 thru 5-9/5-10
4-1 thru 4-2B
4-3 and 4-4
4-11 and 4-12
4-15 thru 4-17/4-18
4-19 thru 4-24
4-27 thru 4-28A/4-28B
4-29 thru 4-38
5-1 thru 5-9/5-10
Chapter 6
6-1 and 6-2
6-4 thru 6-10
6-11 thru 6-20
6-1
6-4 thru 6-10T
6-11 thru 6-20
Chapter 7
7-15 and 7-16
7-21 thru 7-44
7-15 and 7-16
7-21 thru 7-44
Chapter 8
8-3 thru 8-12
8-25 and 8-26
8-3 thru 8-12
8-25 and 8-26
Chapter 9
9-1 and 9-2
9-3 and 9-4
9-9 and 9-10
9-11 thru 9-14
9-1 and 9-2
9-3 and 9-4
9-9 thru 9-10A/9-10B
9-11 thru 9-14
Chapter 5
3. New or changed text material is indicated by a vertical bar in the margin. An illustration change is indicated by a
miniature pointing hand.
4. Retain these sheets in front of manual for reference purposes.
TM 55-1520-234-10
C9
By Order of the Secretary of the Army:
Official:
E. C. MEYER
General, United States Army
Chief of Staff
J. C. PENNINGTON
Major General, United States Army
The Adjutant General
DISTRIBUTION:
To be distributed in accordance with DA Form 12-31, Operator Maintenance requirements for AH-1S (MOD) aircraft.
TM 55-1520-234-10
WARNING PAGE
WARNING
Personnel performing operations, procedures, and practices which are included or implied in
this manual shall observe the following warnings.
Disregard of these warnings and
precautionary information can cause serious injury or loss of life. Procedures outlined in
paragraph 1-6, AR 40-46 are applicable.
STARTING ENGINES
Coordinate all cockpit actions with ground observer. Ensure that rotors and blast area are clear
and fire guard is posted.
GROUND OPERATION
Engine will be started and helicopter operated only by authorized personnel. Reference AR95-1.
GROUNDING HELICOPTER
The helicopter should be electrically grounded when parked and will be grounded during
refueling operations.
HIGH VOLTAGE
Serious burns and/or electrical shock can result from contact with exposed electrical wires or
connections.
FIRE EXTINGUISHER
Exposure to high concentrations of monobromotrifluoromethane (CF3br) extinguishing agent or
decomposition products should be avoided. The agent should not be allowed to come in
contact with the skin, as it may cause frostbite or low-temperature burns.
When helicopter is to be parked where ambient temperature equals or exceeds 90°F (32°C), the
fire extinguisher shall be removed until the next mission.
Should an extinguisher be left in the helicopter inadvertently during a high temperature period,
the extinguisher shall be weight checked prior to the next mission.
ARMAMENT
Loaded weapons, or weapons being loaded or unloaded, shall be pointed in a direction which
offers the least exposure to personnel or property in the event of an accidental firing. Personnel
should remain clear of a hazardous area (forward or aft) of all loaded weapons. Any rotation of
the turret or wing gun pod machine gun barrels or pushing the turret grenade launcher aft may
cause the weapon to fire.
Change 19
a
TM 55-1520-234-10
WARNING PAGE
VERTIGO
The rotating beacon light should be turned off during flight through clouds to prevent
sensations of vertigo as a result of reflections of the light on the clouds.
CARBON MONOXIDE
When smoke, suspected carbon monoxide fumes, or symptoms of anoxia exist, the crew should
immediately ventilate cockpits and open canopy to intermediate position at 40 KIAS or below.
FUEL, OIL, AND HYDRAULIC FLUIDS
Turbine fuels and lubricating oils contain additives which are poisonous and readily absorbed
through the skin. Do not allow them to remain on skin longer than necessary. Prolonged
contact may cause a skin rash. Prolonged contact with hydraulic fluid will cause burns. Refer to
FM 10-68 when handling fuel.
When handling hydraulic fluid (MIL-H-83282), observe the following:
-Prolonged contact with liquid or mist can irritate eyes and skin.
-After any prolonged contact with skin, immediately wash contacted area with soap and water. If liquid contacts
eyes, flush them immediately with clear water.
-If liquid is swallowed, do not induce vomiting; get immediate medical attention.
-Wear rubber gloves when handling liquid. If prolonged contact with mist is likely, wear an appropriate respirator.
-When fluid is decomposed by heating, toxic gases are released.
ELECTROLYTE
Battery electrolyte is harmful to the skin and clothing. If potassium hydroxide is spilled on
clothing or other material, wash immediately with clean water. If spilled on personnel,
immediately start flushing the affected area with clean water. Continue flushing until medical
assistance arrives.
ROTOR BLADES
Personnel shall stay clear of turning main and tail rotor blades. Wind gusts, coast down, or
cyclic movement may cause the main rotor blade to flap down below the height of a person.
Dangerous winds are created by the main rotor blades when blades are at operating rpm.
RADIOACTIVE MATERIALS
Self-luminous dials contain radioactive materials. If such an instrument is broken or becomes
unsealed, avoid personnel contact.
NOISE LEVEL
Sound pressure levels in the helicopter during some operating conditions exceed the Surgeon
Generals hearing conservation criteria as defined in TB MED251. Hearing protection devices,
such as the aviator helmet, ear plugs, or ear muffs shall be worn by all personnel in and around
the helicopter during operation.
WING STORES JETTISON
All jettison safety pins shall be installed when the helicopter is on the ground. Serious injury
can result from accidental ground jettison. Safety pins shall be removed prior to flight. Failure
to do so will prevent emergency jettison of wing stores.
Change 19
b
TM 55-1520-234-10
WARNING PAGE
CANOPY REMOVAL SYSTEM
Ground safety pins shall be installed in pilot and gunner canopy removal arming/firing
mechanisms when the helicopter is on the ground. Pilot safety pin shall be removed prior to
flight. Safety pins shall be installed during engine shutdown check. Debris may be expelled 50
feet outward when system is actuated. Pilot and gunner helmet visor should be down to prevent
eye injury.
JETTISON
Jettison circuit may be activated with battery switch OFF and pilot's wing stores jettison circuit
breaker pulled. For positive deactivation of jettison circuit, open both the pilot's wing stores
jettison circuit breaker and the jettison circuit breaker located in the aft electrical compartment.
Serious injury can result from accidental ground jettison.
Change 30
c/(d blank)
TM 55-1520-234-10
OPERATOR'S MANUAL
HELICOPTER, ATTACK AH-1S
REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS
You can help improve this manual. If you find any mistake or if you know of a way to improve the procedures, please let
us know. Mail your letter, DA Form 2028 (Recommended Changes to Publications and Blank Forms), or DA Form 20282 located in the back of this manual direct to: Commander, U.S. Army Aviation Systems Command, ATTN: AMSAVMPSD, 4300 Goodfellow Boulevard, St. Louis, MO 63120 -1798. A reply will be furnished directly to you.
CHAPTER 1
Page
INTRODUCTION ................................................................................................................. 1-1
CHAPTER 2
Section I
II
III
IV
V
VI
VII
VIII
IX
X
XI
XII
XIII
XIV
HELICOPTER AND SYSTEMS DESCRIPTION AND OPERATION
Helicopter ............................................................................................................................ 2-1
Emergency equipment .........................................................................................................2-10
Engine and related systems .................................................................................................2-11
Helicopter fuel system..........................................................................................................2-16
Flight controls ......................................................................................................................2-16
Hydraulic systems................................................................................................................2-17
Power train system ..............................................................................................................2-18
Main and tail rotors .............................................................................................................2-19
Utility system ......................................................................................................................2-20
Heating, ventilation, cooling and environmental control unit ................................................2-20
Electrical power supply and distribution system ...................................................................2-23
Lighting ...............................................................................................................................2-28
Flight instruments ...............................................................................................................2-29
Servicing, parking, and mooring ..........................................................................................2-33
CHAPTER 3
Section I
II
III
AVIONICS
Communications .................................................................................................................. 3-5
Navigation ...........................................................................................................................3-11
Transponder and radar.........................................................................................................3-15
CHAPTER 4
Section I
II
MISSION EQUIPMENT
Mission avionics................................................................................................................... 4-1
Armament............................................................................................................................ 4-1
CHAPTER 5
Section I
II
III
IV
V
VI
VII
VIII
OPERATING LIMITS AND RESTRICTIONS
General................................................................................................................................
System limits .......................................................................................................................
Power limits .........................................................................................................................
Loading limits.......................................................................................................................
Airspeed limits .....................................................................................................................
Maneuvering limits...............................................................................................................
Environmental restrictions....................................................................................................
Height velocity ....................................................................................................................
Change 19
i
5-1
5-1
5-2
5-5
5-5
5-6
5-8
5-8
TM 55-1520-234-10
Page
CHAPTER 6
Section I
II
III
IV
V
VI
VII
VIII
WEIGHT/BALANCE AND LOADING
General ............................................................................................................................ 6-1
Weight and balance .......................................................................................................... 6-4
Personnel ........................................................................................................................ 6-4
Mission equipment ............................................................................................................ 6-4
Cargo loading (not applicable) ......................................................................................... 6-4
Fuel/Oil ............................................................................................................................ 6-4
Allowable loading ............................................................................................................. 6-4
DD Form 365 ................................................................................................................... 6-16
CHAPTER 7
Section I
II
III
IV
V
VI
VII
VIII
IX
X
XI
PERFORMANCE DATA
Introduction ......................................................................................................................
Performance planning ......................................................................................................
Torque available ..............................................................................................................
Hover ...............................................................................................................................
Takeoff ............................................................................................................................
Climb performance ..........................................................................................................
Cruise ..............................................................................................................................
Drag .................................................................................................................................
Climb-descent and landing................................................................................................
Idle fuel ............................................................................................................................
Airspeed calibration ..........................................................................................................
CHAPTER 8
Section I
II
III
IV
V
NORMAL PROCEDURES
Mission planning ............................................................................................................... 8-1
Operating procedures and maneuvers .............................................................................. 8-3
Instrument flight ................................................................................................................ 8-12
Flight characteristics ......................................................................................................... 8-12
Adverse environmental conditions .................................................................................... 8-17
CHAPTER 9
Section I
II
EMERGENCY PROCEDURES
Helicopter systems............................................................................................................ 9-1
Mission equipment ............................................................................................................ 9-10
APPENDIX A
REFERENCES .................................................................................................................
INDEX
.........................................................................................................................................Index 1
Change 19
ii
7-1
7-5
7-9
7-9
7-10
7-10
.7-19
7-46
7-46
7-47
7-47
A-1
TM 55-1520-234-10
CHAPTER 1
INTRODUCTION
These instructions are for use by the operator. They
apply to AH-1S helicopter.
Your flying experience is recognized, and therefore,
basic flight principles are not included. THIS MANUAL
SHALL BE CARRIED IN THE HELICOPTER AT ALL
TIMES.
1-2. Warnings, Cautions and Notes Definition.
1-4. Appendix A, References.
Warnings, cautions and notes are used to
emphasize important and critical instructions and are
used for the following conditions:
Appendix A is a listing of official publications cited
within the manual, applicable to and available for flight
crews.
1-1. General.
WARNING
1-5. Index.
An operating procedure, practice,
etc., which, if not correctly followed,
could result in personal injury or
loss of life.
The index lists, in alphabetical order, every titled
paragraph, figure, and table contained in this manual.
Chapter 7, performance data, shall have an additional
index within the chapter.
1-6. Army Aviation Safety Program.
CAUTION
Reports necessary to comply with the safety
program are prescribed in AR 385-40.
An operating procedure, practice,
etc., which, if not strictly observed,
could result in damage to or
destruction of equipment.
1-7. Destruction of Army Materiel to Prevent Enemy
Use.
NOTE
For information concerning destruction of Army
materiel to prevent enemy use, refer to TM 750-244-1-5.
An operating procedure, practice,
etc., which it is essential to highlight.
1-8. Deleted.
1-3. Description.
1-9. Forms and Records.
This manual contains the best operating instructions
and procedures for AH-1S (MOD) helicopters under
most circumstances. The observance of limitations,
performance and weight balance data provided is
mandatory. The observance of procedure is mandatory
except when modification is required because of
multiple emergencies, adverse weather, terrain, etc.
Change 19
Army aviators flight record and helicopter
maintenance records which are to be used by crew
members are prescribed in DA PAM 738-751 and TM
55-1500-342-23.
1-10. Deleted.
1-1
TM 55-1520-234-10
1-11. Explanation of Change Symbols.
1-12. Helicopter Designation System.
Changes, except as noted below, to the text and
tables, including new material on added pages, are
indicated by a vertical line in the outer margin extending
close to the entire area of the material affected;
exception: pages with emergency markings, which
consist of black diagonal lines around three edges, may
have the vertical line or change symbol placed along the
inner margins. Symbols show current changes only. A
miniature pointing hand symbol is used to denote a
change to an illustration. However, a vertical line in the
outer margin, rather than miniature pointing hands, is
utilized when there have been extensive changes made
to an illustration. Change symbols are not utilized to
indicate changes in the following:
The designation system prescribed by AR 70-50 is
used in helicopter designations as follows:
a. Introductory material.
b. Indexes and tabular data where the change cannot be identified.
c. Blank space resulting from the deletion of text,
an illustration, or a table.
d. Correction of minor inaccuracies, such as
spelling, punctuation, relocation of material, etc., unless
such correction changes the meaning of instructive
information and procedures.
Change 19
1-13. Use of Shall, Will, Should, and May.
Use "shall" whenever it is necessary to express a
provision that is binding. Use "should" and "may"
whenever it is necessary to express non-mandatory
provisions. "Will" may be used to express a declaration
of purpose.
1-2
TM 55-1520-234-10
CHAPTER 2
HELICOPTER AND SYSTEMS DESCRIPTION AND OPERATION
Section I. HELICOPTER
air ventilation is provided for the electronic equipment
cooling.
2-1. General Description.
The AH-1S helicopter is a tandem seat, two- place
(pilot and gunner), single engine helicopter.
The
maximum gross weight for takeoff is 10,000 pounds.
2-2. General Arrangement.
Figure 2-1 depicts the general arrangement of the
items which are referred to in the exterior check
paragraph of Chapter 8, Section II.
2-3. Principal Dimensions.
Figure 2-2 depicts the principal dimensions of the
helicopter to the nearest inch.
2-4. Turning Radius.
Figure 2-3 depicts the minimum turning radius of the
helicopter.
2-5. Fuselage.
The fuselage is that forward portion of the airframe
which extends from the nose of the helicopter to the
forward end of the tailboom.
The fuselage is
constructed of aluminum alloy skin and aluminum,
titanium and fiberglass honeycomb beams. Honeycomb
deck panels and a minimum of bulkheads attached to
the main beams produce a box-beam structure. The
main beams are the main primary structure and
supports the engine, transmission, tailboom, landing
gear, wings, fuel cells, turret, and telescopic sight unit.
2-6. Tailboom.
The tailboom is that portion of the airframe which is
bolted to the fuselage and extends to the aft end of the
helicopter.
It is tapered semimonocoque structure
employing aluminum skins, honeycomb panels,
longerons, and stringers. It supports the tail rotor, fin,
and synchronized elevators. It, also, houses the tail
rotor driveshaft and some electronic equipment. Forced
Change 15
2-7. Wing.
The fixed cantilever wing provides additional lifting
surfaces and supports the wing stores pylons. It is
constructed of two main spars, ribs, aluminum and/or
aluminum honeycomb skin. It has a span of 10 feet and
9 inches, (including tip), tapered airfoil, and a mean cord
of 2 feet and 6 inches. Each wing has two pylons. The
inboard pylons are fixed and the outboard pylons are
articulated by hydraulic actuators. Both Inboard and
Outboard pylons will each support 670 pounds of weight.
2-8. Landing Gear.
a. Main Landing Gear. The main landing gear
consists of two aluminum lateral mounted arched
crosstubes and two aluminum longitudinal skid tubes
attached to the crosstubes. Each crosstube is enclosed
in a fiberglass fairing for aerodynamic purposes. Each
slid tube has a steel skid shoe on the bottom to
minimize skid wear.
b. Tail Skid. The steel tubular type tail skid is
installed on the aft end of the tailboom to protect the tail
rotor blades during tail-low landing.
2-9. Canopy.
The canopy is the transparent panels on the upper
portion of the fuselage which encloses the crew
compartment.
The canopy consists of one piece
windshield extending from the nose of the helicopter
(over the gunner and pilot heads) to the pylon, the
gunner door and pilot window on the left side, and the
gunner window and pilot door on the right side. The
canopy provides maximum field of view for the gunner.
The pilot forward field of view is limited, but excellent in
all other quadrants. The canopy removal system is
used to remove the pilot and gunner windows and doors
during emergencies. The system is covered in Chapter
2, Section II.
2-1
TM 55-1520-234-10
Figure 2-1. General arrangement (Sheet 1 of 2)
2-2
TM 55-1520-234-10
Figure 2-1. General Arrangement (Sheet 2 of 2)
Change 19
2-3
TM 55-1520-234-10
Figure 2-2. Principal dimensions
2-10. Personnel Doors.
Both doors are hinged on top and swing outward
and up to provide access. Both doors have supports
incorporating locks to hold the door in the full open and
intermediate positions. The lock is engaged only when
the door handle is in the horizontal position. Both doors
have an external padlock. Both doors are manually
operated. The handle must be rotated to move the door
from one position to another (closed, intermediate, full
opened).
2-11. Seats - Pilot and Gunner.
a. Construction. Both seats, side-shoulder panels,
and head protective panels are made of opaque armor
material which provides armor protection. Both seats
are equipped with contoured seat cushions and back
supports made of foam and open mesh for vibration
attenuation and crew comfort.
Change 19
b. Pilot Seat. The pilot seat is vertically adjustable
nonreclining type. The vertical adjustment is reclined at
15 degrees. The vertical height adjustment handle
(figure 24) is under the left side of the seat. The seat is
equipped with a lap safety belt and inertia reel shoulder
harness.
c. Gunner Seat. The gunner seat is affixed seat
(non-adjustable and nonreclining). The seat is equipped
with a lap safety belt and inertia reel shoulder harness.
The seat also has arm rests.
d. Inertia Reel Shoulder Harness. An inertia reel
shoulder harness is incorporated in the pilot and gunner
seats with a manual lock-unlock control handle (figures
2-4 and 2-5). The handles are located to left front of
each seat. With the control in the unlocked position, the
reel cable will extend to allow the occupant to lean
forward; however, the reel will automatically lock when
helicopter encounters an impact force of two to 'three
"g" deceleration. Locking of the reel can be
2-4
TM 55-1520-234-10
Figure 2-3. Turning radius
accomplished from any position and the reel will
automatically take up the slack in the harness. To
release the lock, it is necessary to lean back slightly to
release tension on the lock and move the control handle
to the lock and then unlock position. It is possible to
have pressure against the seat back whereby no
additional movement can be accomplished and the lock
cannot be released. If this condition occurs, it will be
necessary to loosen shoulder harness. Manual locking
of the reel should be accomplished for emergency
landings.
2-12. Crew Compartment Diagrams.
The upper forward portion of the fuselage is the
crew compartment. Tandem seating is provided with
the pilot elevated in the rear seat.
b. Gunner Station. Figure 2-5 depicts the locations
of equipment in the gunner station.
2-13. Instruments and Controls.
a. Pilot Instrument Panel. Figure 2-4 depicts the
locations of instruments, switches, panels, and decals in
the pilot instrument panel.
b. Gunner Instrument Panel. Figure 2-7 depicts
the locations of instruments, switches, panels, and
decals in the gunner instrument panel.
c. Other Instruments and Controls. These items
are depicted on the pilot and gunner station diagrams
(figures 2-4 and 2-5) or in the chapter/section which
describes their related systems.
a. Pilot Station. Figure 2-4 depicts the locations of
equipment in the pilot station.
Change 30
2-5
TM 55-1520-234-10
Figure 24. Pilot Station Diagram (Sheet 1 of 2)
Change 19
2-6
TM 55-1520-234-10
Figure 2-4. Pilot station diagram (Sheet 2 of 2)
Change 14
2-7
TM 55-1520-234-10
Figure 2-5. Gunner station diagram
Change 19
2-8
TM 55-1520-234-10
Figure 2-7. Gunner instrument panel
Section II. EMERGENCY EQUIPMENT
NOTE
2-15. First Aid Kit.
An aeronautical type first aid kit is located on the
bulkhead behind the pilot seat.
The emergency equipment locations
and emergency procedures are
covered in Chapter 9.
2-16. Canopy Removal System.
2-14. Portable Fire Extinguisher.
A portable hand-operated fire extinguisher is
charged with monobromotrifluoromethane (CF3Br). It is
located on the left side of the bulkhead behind the
gunner seat.
The extinguisher could discharge if
temperature of 32°C (90°F) is exceeded.
Change 14
Window cutting assemblies are mounted in the pilot
and gunner window frames. The linear ex plosive is
contained with the cutting assemblies. The cutting
assemblies are controlled by the pilot or gunner
arming/firing mechanisms. Rotating the arming/firing
mechanism handle 90 degree counterclockwise (torque
required 9 to 12 inch-
2-10
TM 55-1520-234-10
pounds) will arm the cutting assemblies. Pulling the
handle (28 to 32 pounds tension) will fire the percussion
primer causing the cutting assemblies to be detonated.
The explosive force will be outward and cut the four
transparent panels out of their frames simultaneously. If
handle has been rotated but not pulled, the handle can
be rotated and the safety pin installed. DA Form 240813 entry required.
WARNING
Debris may be expelled 50 feet
outward when system is actuated.
Section III. ENGINE AND RELATED SYSTEMS
2-17. Engine.
The helicopter is equipped with a model T53-L703
engine (figure 2-8). The engine, in this installation, is
derated by limitation of the helicopter transmission to
1290 shp (56 psi torque) for 30 minutes and 1134 shp
(50 psi torque) for continuous operation at 6600 rpm.
The engine compartment is cooled by ram ambient air.
b. Particle Separator. The self-purging particle
separator is located over the engine air inlet in the
transmission compartment.
The purpose of the
separator is to remove particles from the engine inlet air
and automatically eject them overboard.
2-20. Engine Inlet Anti-Icing/Deicing System.
WARNING
2-18. Engine Protection.
The system will not deice or prevent
icing of the FOD screen or particle
separator. A power loss will occur if
the formation of ice in the FOD
screen
or
particle
separator
obstructs the flow of ambient air to
the engine.
a. Armor. Armor material is located on the left and
right engine compartment doors to provide armor
protection for the engine compressor, fuel control, oil
filter, and fuel filter.
b. Missile. An infrared (IR) exhaust duct (figure 21) may be installed on the engine tailpipe to achieve
engine exhaust IR signature reduction.
2-19. Air Induction System.
The helicopter is equipped with an automatic engine
air inlet system. Ambient air enters the transmission
compartment door air inlet, then routed through the
foreign object damage (FOD) screen, and the particle
separator to the engine air inlet.
a. Foreign Object Damage (FOD) Screen. The
FOD screen is mounted around the particle separator on
the forward end of the engine in the transmission
compartment. The purpose of the screen is to prevent
debris from entering the particle separator.
Change 9
a. General. The system consists of a hot air
solenoid valve on the engine, controlled by the pilot or
gunner DE-ICE switch (figures 2-9 and 2-10), powered
by the 28 Vdc essential bus, and protected by the ENG
DE-ICE circuit breaker.
b. Purpose. The system prevents ice from forming
in the engine air inlet.
c. Operation. If ice accumulation is suspected, the
pilot or gunner DE-ICE switch is placed in the DE-ICE
position. This action causes the hot air solenoid valve
to route engine bleed air to the engine air inlet.
2-11
TM 55-1520-234-10
Figure 2-8. Engine
Change 9
2-12
TM 55-1520-234-10
Figure 2-9. Pilot engine control panel
NOTE
A rise in the turbine gas temperature
(TGT) will occur when the pilot or
gunner DE-ICE switch is in the
DEICE position. Deice operation will
become continuous if the hot air
solenoid valve (ENG DE-ICE) circuit
fails.
2-21. Engine Fuel Control System.
a. Engine Mounted Component. The fuel control
assembly is mounted on the exterior left side of the
engine. The assembly is controlled by the pilot or
gunner throttle and GOV switch. The assembly consists
of a metering section, a computer section, and an
overspeed governor. The metering section pumps fuel
to the engine. The computer section determines the
rate of fuel delivery. The overspeed governor maintains
a constant rpm.
b. Crew Controls.
(1) Throttle. Rotating the pilot or gunner grip
type throttle (figure 2-4 and 2-5) to the full open position
allows the overspeed governor to maintain a constant
rpm. Rotating the throttle toward the closed position will
cause the rpm to be manually selected instead of
automatically selected by the overspeed governor.
Rotating the throttle past the engine idle stop to the fully
closed position shuts off fuel flow. A solenoid operated
idle stop is incorporated to prevent inadvertent throttle
closure. The idle stop is controlled by-the pilot ENGINE
IDLE STOP REL switch (figure 2-4)
Change 19
Figure 2-10. Gunner miscellaneous control panel
and the gunner IDLE STOP RELEASE switch (figure 210). The engine idle stop release circuit is powered by
the 28 Vdc essential bus and protected by the IDLE
STOP SOL circuit breaker. Friction can be induced into
both throttles by rotating the pilot throttle friction ring
(figure 2-4) counterclockwise. The ring is located on the
upper end of the pilot throttle.
(2) Governor Switches. The pilot or gunner
GOV switches (figures 2-9 and 2-10) AUTO position
permits the overspeed governor to automatically control
the engine rpm. The EMER position permits the pilot
and gunner to manually control the engine rpm. The
governor circuit is powered by the 28 Vdc essential bus
and protected by the GOV CONT circuit breaker.
2-13
TM 55-1520-234-10
2-22. Engine Oil Supply System.
a. Description. The engine oil system is a dry
sump, pressure type, and completely automatic. The oil
tank is located in the upper pylon fairing. It will self-seal
a 30 caliber projectile hole and is equipped with
deaeration provisions. Oil is gravity fed from tank to
engine driven oil pump which provides pressure and
scavenging for the system.
b. Cooling. Engine oil cooling is accomplished by
an oil cooler and a turbine fan. The engine and
transmission oil coolers use the same fan.
governor. No crew controls are provided or required.
The compensator will hold N2 rpm to ± 40 rpm when
properly rigged. Droop is defined as the speed change
in engine rpm (N2) as power is increased from a no-load
condition. It is an inherent characteristic designed into
the governor system.
Without this characteristic,
instability would develop as engine output is increased,
resulting in N1 speed overshooting or hunting the value
necessary to satisfy the new power condition. Design
droop of the engine governor system is as much as 300
to 400 rpm (flat pitch to full power). If N2 power were
allowed to droop, other than momentarily, the reduction
in rotor speed could become critical.
2-26. Engine Instruments and Indicators.
c. Switching Action. The pilot ENG OIL BYP
switch (figure 2-9) AUTO position permits the oil to
automatically bypass the oil cooler when the oil tank is
approximately 3.8 quarts low.
The OFF position
deactivates the automatic bypass feature causing the oil
to pass through the oil cooler regardless of the oil tank
level. The switch circuit is powered by the 28 Vdc
essential bus and protected by the FUEL & OIL valve
circuit breaker.
2-23. Ignition-Starter System.
The pilot ignition-starter trigger switch (figure 2-4) is
depressed and held to start the engine. The switch is
released when the engine starts or the time limit expires
. The pilot FUEL switch (figure 2-9) must be in the
FUEL position and the pilot ignition keylock switch
(figure 24) in the ON position to complete the ignition
circuit. The circuits are powered by the 28 Vdc essential
bus and protected by the STARTER RELAY and IGN
SYS IGN SOL circuit breakers.
2-24. Governor RPM Switches.
The pilot GOV RPM switch (figure 24) and the
gunner RPM switch (figure 2-10) INCR position permits
the regulated power turbine speed to increase to 6700 ±
50 rpm. The DECR position permits the speed to
decrease to 6000 ± 50 rpm. The switch is released
when the desired rpm is obtained. The circuit is
powered by the 28 Vdc essential bus and protected by
the GOV CONT circuit breaker.
2-25. Droop Compensator.
A droop compensator maintains engine rpm (N2) as
power demand is increased by the pilot.
The
compensator is a direct mechanical linkage between the
collective stick and the speed selector lever on the N2
Change 30
a. Torquemeters.
The pilot and gunner
torquemeters (figures 2-4 and 2-7) displays the pounds
per square inch (psi) of the torque imposed upon the
engine output shaft. Each torquemeter is powered by a
separate transmitter. The circuit is powered by the 26
Vac system and protected by the TORQUE PRESSURE
IND circuit breaker.
b. Turbine Gas Temperature (TGT) Indicators.
The pilot and gunner indicators (figures 24 and 2-7)
display the Celsius degrees of the air in the turbine inlet
area. The indicators do not require any connections to
the helicopter electrical system.
c. Dual Tachometers.
The pilot and gunner
tachometer (figures 2-4 and 2-7) display the rpm of the
engine and main rotor. The tachometer outer scale is
marked ENGINE and the inner scale is marked ROTOR.
The ENGINE and ROTOR needles are synchronized
during normal helicopter operation. The tachometers do
not require any connections to the helicopter electrical
system.
d. Gas Producer Tachometers. The pilot and
gunner tachometers (figures 2-4 and 2-7) display the
rpm of the gas producer turbine speed in percent. The
tachometers do not require any connections to the
helicopter electrical system.
e. Oil Temperature Indicator. The pilot indicator
(figure 2-4) displays the Celsius degrees of the engine
oil at the engine oil inlet. The circuit is powered by the
28 Vdc essential bus and protected by the TEMP IND
ENG & XMSN circuit breaker.
2-14
TM 55-1520-234-10
f. Oil Pressure Indicator.
The pilot indicator
(figure 2-4) displays the psi pressure of the engine oil at
the pressure side of the oil pump. The circuit is
powered by the 26 Vac system and protected by the
ENG OIL PRESSURE IND circuit breaker.
to illuminate.
This illumination identifies the
contaminated unit. The PRESS TEST switch is used to
check the CHIP DET panel lights. The CHIP DET panel
receives electrical power from the CHIP DETECTOR
caution lights.
g. Oil Pressure Caution Lights. The pilot and
gunner ENGINE OIL PRESS caution lights (figure 2-18)
will illuminate when the engine oil pressure is below safe
limits.
j. Fuel Pump Caution Lights. The pilot and gunner
ENG FUEL PUMP caution lights (figure 2-18) will
illuminate when either element of the engine driven fuel
pump fails.
h. Oil Bypass Caution Light. The pilot ENGINE
OIL BYPASS caution light (figure 2-18) will illuminate
when the oil tank level is approximately 3.8 quarts low.
The engine oil will bypass the oil cooler when the light
illuminates if the pilot ENG OIL BYP switch (figure 2-9)
is in the AUTO position. The oil will not bypass the oil
cooler if the switch is in the OFF position.
k. Governor Caution Lights. The pilot and gunner
GOV EMER caution lights (figure 2-18) will illuminate
when the pilot or gunner GOV switch (figures 2-9 and 210) is in the EMER position
i. Oil Chip Detector.
(1) Chip Detector Caution Lights. The pilot
and gunner CHIP DETECTOR caution lights (figure 218) will illuminate when sufficient metal chips are
detected in the engine, 42°gearbox, 90°gearbox, or the
transmission oil. The chip detector panel is used to
identify which unit is contaminated.
Figure 2-11. Pilot miscellaneous control panel.
(2) Chip Detector Panel. The pilot CHIP DET
panel (figure 2-11) is used to identify the contaminated
component.
When the pilot and gunner CHIP
DETECTOR caution light illuminates, pressing the CHIP
DET panel will cause the word ENG, 42°, 90°, or XMSN
Change 30
2-15
TM 55-1520-234-10
Section IV. HELICOPTER FUEL SYSTEM
NOTE
2-27. Fuel Supply System.
The helicopter is equipped with a crashworthy fuel
system. The system is designed with the potential of
containing fuel during a severe, but survivable crash
impact to reduce the possibility of fire. The system has a
50 caliber ballistic protection level.
2-28. Controls and Indicators.
a. Fuel Switch. The pilot FUEL switch (figure 2-9 )
FUEL position energizes the forward and aft boost pumps,
opens the fuel shutoff valve, and completes the ignition
circuit. The aft boost pump circuit is powered by the 28
Vdc none essential bus. T he other circuits are powered
by the 28 Vdc essential bus. The circuits are protected by
the STARTER RELAY, IGN SYS IGN SOL, FUEL & OIL
VALVE, FUEL BOOST FOOD and FUEL BOOST AFT
circuit breakers.
b. Fuel Quantity Indicator. The pilot indicator (figure
2-4) displays the pounds of fuel in the fuel cells. The
circuit is powered by the 115 Vac system and protected by
the FUEL QTY IND circuit breaker.
c. Fuel Quantity Indicator Test Switch. The pilot fuel
gauge test switch (figure 2-4) is used to test the fuel
quantity indicator operation. Pressing the switch will
cause the indicator pointer to move from the actual
reading to a lesser reading. Releasing the switch will
cause the pointer to return to the actual reading. The
circuit is powered by the 115 Vac system and protected by
the FUEL QTY IND circuit breaker.
Low fuel caution systems alert the
pilot that the fuel level in the tank has
reached a specified level (capacity).
Differences in fuel densities due to
temperature and fuel type will vary the
weight of the fuel remaining and the
actual time the aircraft engine(s) may
operate.
Differences
in
fuel
consumption rates, aircraft attitude
and operational condition of the fuel
subsystem will also affect actual time
the aircraft engine(s) may operate.
d. Low Quantity Caution Lights.
The pilot and
gunner 10% FUEL caution lights (figure 2-18) will
illuminate when there is approximately 10% of the total
fuel remaining (209 pounds). The illumination of this light
does not mean a fixed time period remains before fuel
exhaustion, but is an indication that a low fuel condition
exists.
e. Fuel Pressure Indicator. The pilot indicator (figure
2-4) displays the psi pressure of the fuel being delivered
by boost pumps from the fuel cells to the engine. The
circuit is powered by the 26 Vac system and protected by
the FUEL PRESSURE IND circuit breaker.
f. Low Fuel Pressure Caution Lights. The pilot FWD
FUEL BOOST and AFT FUEL BOOST caution lights
(figure 2-18) will illuminate when the boost pumps in the
forward/aft fuel cell fail or FUEL switch is off.
g. Fuel Filter Caution Lights. The pilot and gunner
FUEL FILTER caution lights (figure 2-18) will illuminate
when the filter in the fuel supply line becomes partially
obstructed.
Section V. FLIGHT CONTROLS
2-29. Description.
The flight control system is a positive mechanical
type, actuated by conventional helicopter controls.
Complete controls are provided for both pilot and gunner.
The gunner controls are slaved to the pilot controls. The
system includes a cyclic system, a collective control
system, a tail rotor system, a force trim system, and a
stability and control augmentation system (SCAS).
the main rotor. The stick fore and aft movement also
changes the synchronized elevator (figure 2-1) attitude to
assist controllability and cg range.
2-31. Collective Control System.
The system is operated by the collective stick (figures
24 and 2-7). Moving the stick up or down will determine
the angle of attack and lift developed by the main rotor
resulting in the ascent or descent of the helicopter.
2-30. Cyclic Control System.
2-32. Tail Rotor Control System.
The system is operated by the cyclic stick (figures 2-4
and 2-5) movement. Moving the stick in any direction will
The system is operated by the pedals (figures 2-4 and
produce a corresponding movement of the helicopter
2-5).
Pushing a pedal will alter the pitch of
which is the result of a change in the plane of rotation of
Change 30
2-16
TM 55-1520-234-10
the tail rotor resulting in directional control. Also, the
pedals may be used to pivot the helicopter on its own
vertical axis. A pedal adjuster (figure 2-5) is provided to
adjust the pedal distance for individual comfort Heel
rests are provided for the gunner to prevent inadvertent
pedal operation.
2-33. Force Trim System.
The system incorporates a magnetic brake and
gradient in the cyclic and pedal control systems to
provide artificial feel into the system. Also, it provides a
means to trim the controls. Placing the FORCE TRIM
switches (figures 2-9 and 2-10) in the TRIM position will
induce artificial feel into the systems. Depressing the
cyclic stick force trim switch (figures 2-4 and 2-6) will
cause the magnetic brake and force gradient to be
repositioned to correspond to the positions of the cyclic
stick and pedals thus providing trim. The system is
powered by the 28 Vdc essential bus and protected by
the FORCE TRIM circuit breaker.
b. Control Panel. The SCAS control panel (figure
2-12) contains a POWER switch for applying 28 Vdc
(essential bus) and 115 Vac operating voltages to the
system. The circuits are protected by the SAS PWR dc
and SAS PWR ac circuit breakers. It also contains
three magnetic latching channel engage switches which
energize electric solenoid valves controlling hydraulic
pressure to the system. The panel has three NO-GO
lights; one associated with each PITCH, ROLL, and
YAW channel engage switch.
These lights are
illuminated during the warmup to indicate the presence
of current in each associated channel actuators. When
engagement is made, the NO-GO lights are locked out
of the circuit and do not operate as malfunction
indicators. Disengaging a channel, however, restores
the associated light to operation. The NO-GO lights
have a built-in press-to-test feature for insuring that the
indicator is operational, but this feature works only prior
to channel engagement.
2-34. Stability and Control Augmentation System
(SCAS).
a. Description. The SCAS is a three-axis, limited
authority rate reference augmentation system. The
SCAS provides a smoother flying weapon platform and
cancels undesired motion of the helicopter during flight.
This is accomplished by inducing an electrical pilot input
into the flight control system to augment the pilot
mechanical input.
Figure 2-12. Pilot SCAS control panel
c. SCAS Release switch. The cyclic grip mounted
switch (figures 2-4 and 2-5) is used to disengage the
pitch, roll, and yaw channels simultaneously. The
channels are re-engaged by the PITCH, ROLL, and
YAW switches on the SCAS control panel.
CAUTION
Should an engagement be attempted
during this warmup period, the
actuator will make an abrupt input to
the flight controls at the moment of
engagement.
Section VI. HYDRAULIC SYSTEMS
2-35. Description.
2-36. Hydraulic System No. 1.
The hydraulic system is a dual system (No. 1 and
No. 2 system) used to minimize the force required by
the pilot to move the cyclic, collective, and foot pedal
controls. The No. 1 and No. 2 systems are installed to
provide maximum separation to reduce the probability
of a single projectile incapacitating both systems.
The No. 1 system provides hydraulic power to the
cyclic controls, collective controls, foot pedal controls,
SCAS yaw controls and charges emergency collective
control system. The No. 1 system is located on the left
side of the helicopter.
Change 19
2-17
TM 55-1520-234-10
2-37. Hydraulic System No. 2.
2-43. Emergency Hydraulic Control System.
The No. 2 system provides hydraulic power to the
cyclic controls, collective controls, turret system, SCAS
pitch and roll controls and articulated wing pylons. The
No. 2 system is located on the right side of the
helicopter.
a. Emergency Collective Control System. The
system provides limited collective control operations if
the No. 1 and No. 2 systems fail. The pilot and gunner
EMER COLL HYD switches (figures 2-4 and 2-7) control
the emergency system. The switch is in the OFF
position during normal operations. With the switch in
the OFF position when the No. 1 and No. 2 systems fail
will cause sufficient fluid to be retained in an
accumulator for an emergency landing. Placing the
switch in the ON position will allow four full strokes of
the collective stick: A stroke is a maximum movement in
one direction. The accumulator has a pressure gage
which displays the psi of its compressed nitrogen.
2-38. Test Switch.
The pilot HYD TEST switch (figure 2-9) is used to
test the No. 1 and No. 2 hydraulic systems. Holding
the switch in the SYS 1 position will cause the No. 1
system to be the only system supplying hydraulic
pressure. Similar action occurs when the switch is held
in the SYS 2 position.
The No. 1 and No. 2 reservoirs are provided with a
fluid sight glass. Both sight glasses can only be seen
from the left hydraulic compartment door.
b. Emergency Cyclic Control System. The system
provides limited cyclic control operations if the No. 1
and No. 2 systems fail. The system is automatic, using
spring pressure in a small accumulator, and has no
external controls.
2-40. Filter Indicators.
2-44. Armament Hydraulic System.
The No. 1 and No. 2 pressure and return filters are
provided with a differential pressure indicator. The red
indicator pops out when the filter needs changing or
during cold weather operation.
a. Turret System. The system is powered by the
No. 2 system and enables the turret to be traversed
through varied positions in elevation and azimuth. The
system is controlled by the turret controls. The system
electrical circuit is powered by the 28 Vdc essential and
nonessential busses and the 115 Vac system. The
circuit is protected by the dc HYD CONT, dc TURRET
POWER, ac HSS PWR, and ac WEAPON SIGHT
circuit breakers.
2-39. Reservoir Fluid Sight Glasses.
2-41. Low Pressure Caution Lights.
The pilot and gunner HYD PRESS #1 and HYD
PRESS #2 caution lights (figure 2-18) will illuminate
when the hydraulic pressure is below safe limits.
2-42. Electrical Circuit.
The hydraulic electrical circuit is powered by the 28
Vdc essential bus and protected by the HYD CONT
circuit breaker.
b. TOW Missile System. The system is powered
by the No. 2 system and is used to position the
outboard articulated wing pylons during TOW missile
operations. The system is controlled by she TOW
missile controls.
The system electrical circuit is
powered by the 28 Vdc essential bus and the 115 Vac
system. The circuit is protected by the dc HYD CONT,
ac TOW PWR, and ac SECU PWR circuit breakers.
Section VII. POWER TRAIN SYSTEM
2-45. Transmission.
The transmission transfers engine power to the main
rotor through the mast assembly and to the' tail rotor
through a series of driveshafts and gearboxes. The
transmission has a self-contained pressure oil system.
The oil is cooled by an oil cooler and turbine fan. The
Change 30
transmission and engine oil coolers use the same fan.
The oil system has an automatic bypass system which
causes the oil to bypass the cooler when a flow
differential exists between pump and cooler output. Two
oil level sight glasses, an oil filler cap, and a magnetic
chip detector are provided.
2-18
TM 55-1520-234-10
2-46. Gearboxes.
(figure 2-18) will illuminate when the transmission oil
pressure drops below safe limits.
a. Intermediate Gearbox-42 Degree. The gearbox
is located at the base of the vertical fin. It provides a 42
degree change of direction of the tail rotor driveshaft.
The gearbox has a self-contained wet sump oil system.
An oil level sight glass, a filler cap, and a magnetic chip
detector are provided.
b. Tail Rotor Gearbox-90 Degree. The gearbox is
located near the top of the vertical fin. It provides a 90
degree change of direction of the tail rotor driveshaft
and final gear reduction for the tail rotor output shaft
speed. The gearbox has a self-contained wet sump oil
system. An oil level sight glass, a filler cap, and a
magnetic chip detector are provided.
2-47. Driveshafts.
c. Transmission Oil Temperature Indicator. The
pilot indicator (figure 2-4) displays the Celsius
temperature of the transmission oil. The electrical
circuit is powered by the 28 Vdc essential bus and
protected by the TEMP IND ENG & XMSN circuit
breaker.
d. Transmission Oil Slot Caution Lights. The pilot
and gunner XMSN OIL HOT caution lights (figure 2-18)
will illuminate when the transmission oil temperature
exceeds the safe limits.
e. Transmission Oil Cooler Bypass Caution Light.
The pilot XMSN OIL BYPASS caution light (figure 2-18)
will illuminate when the automatic oil bypass system is
activated causing the oil to bypass the oil cooler.
a. Main Driveshaft. The main driveshaft connects
the engine output shaft to the transmission input drive
quill.
f. Transmission and Gearboxes Chip Detector.
b. Tail Rotor Driveshaft. The tail rotor driveshaft
consists of five driveshaft and three hanger bearing
assemblies. The assemblies and the 42 and 90 degree
gearboxes connect the transmission tail rotor drive quill
to the tail rotor
(1) Chip Detector Caution Lights. The pilot
and gunner CHIP DETECTOR caution lights (figure 218) will illuminate when sufficient metal chips are
detected in the engine, 42° gearbox, 90° gearbox, on
the transmission oil. The chip detector panel is used to
identify which unit is contaminated.
2-48. Indicators and Caution Lights.
a. Transmission Oil Pressure Indicator. The pilot
indicator (figure 2-4) displays the psi of oil pressure of
the transmission oil system. The electrical circuit is
powered by the 26 Vac system and protected by the
XMSN OIL PRESSURE IND circuit breaker.
b. Transmission Oil Low Pressure Caution Lights.
The pilot and gunner XMSN OIL PRESS caution lights
(2) Chip Detector Panel. The pilot CHIP DET
panel (figure 2-11) is used to identify the contaminated
component.
When the pilot and gunner CHIP
DETECTOR caution light illuminates, pressing the CHIP
DET panel will cause the word ENG, 42°, 90° or XMSN
to illuminate.
This illumination identifies the
contaminated unit. The PRESS TEST switch is used to
check the CHIP DET panel lights. The panel receives
electrical power from the, caution panel light circuit
breaker.
Section VIII. MAIN AND TAIL ROTORS
2-49. Main Rotor.
in the hub with a retaining bolt assembly and is held in
alignment by adjustable drag braces.
a. Description
(1) B540 The main rotor blades are metal,
bonded assemblies. Each blade is attached ill the hub
with a retaining boll assembly and is held in alignment
by adjustable drag braces.
(2) K747 The main rotor blades are glass
fiber epoxy resin bonded assemblies with a rubber
erosion guard. The skin is basket weave which will not
be as smooth as a metal blade. Each blade is attached
Change 30
(3) The main rotor is driven by the mast
which is connected to the transmission. The rotor rpm is
governed by the engine rpm during powered flight. The
rotor tip path plane is controlled by the cyclic stick. The
rotor pitch is controlled by the collective stick.
b. Hub Moment Spring. As an aid in controlling
rotor flapping, a hub moment spring kit has been
installed in the rotor system.
2-19
TM 55-1520-234-10
Two nonlinear elastomeric springs are attached to a
support affixed to the mast. The hub moment springs
provide an additional margin of safety in the event of an
inadvertent excursion of the helicopter beyond the
approved flight envelope.
c. RPM Indicators. The pilot and gunner indicators
are part of the dual tachometers (figures 2-4 and 2-7).
The tachometer inner scale displays the rotor rpm. The
inner scale pointer is marked with an R.
2-50. Tail Rotor.
The tail rotor is driven by the 90 degree gearbox
which is connected to the transmission by the tail rotor
driveshaft assemblies and the 42 degree gearbox. The
rotor rpm is governed by the transmission rpm. The
rotor blade pitch is controlled by the foot pedals.
Section IX. UTILITY SYSTEM
2-52. Canopy Defrosting, Deicing and Rain Removal
Systems.
2-51. Pitot Tube Heater.
The pitot tube (figure 2-1) is equipped with an
electrical heater. The pilot PITOT BEAT switch (figure
2-4) HEAT position activates the heater in the tube and
prevents ice from accumulating in the pitot tube. The
OFF position deactivates the heater. The electrical
circuit is powered by the 28 Vdc nonessential bus and
protected by the PITOT HEAT circuit breaker.
These systems are considered to be part of the
environmental control system. See section X of this
chapter.
Section X. HEATING, VENTILATION, COOLING, ENVIRONMENTAL CONTROL UNIT
2-53. Environmental Control Unit (ECU).
c. ECU Controls.
a. ECU Functions.
NOTE
Under certain conditions a plume
may be observed at the air vents in
the crew compartment. The plume
may appear to be smoke, but is
actually condensation.
(1) Heats/cools the crew compartment.
(2) Removes moisture from the air supplied
to the crew compartment.
(3) Defrosts, defogs, and deices the canopy.
(4) Removes rain from the canopy.
(1) The pilot ECU controls and their functions
are shown on figure 2-13.
(5) Provides ambient air ventilation to the
crew compartment.
(2) The pilot and gunner controls the volume
and direction of the air entering the crew compartment
using the adjustable air vents in their instrument panels.
b. ECU Power Source. The ECU is electrically
controlled and engine bleed air powered. The circuit is
powered by the 28 Vdc nonessential bus and protected
by the ECU CONT circuit breaker.
(3) The pilot and gunner controls the volume
of air entering their seat cushions using the valve at the
top of each seat.
Change 30
2-20
TM 55-1520-234-10
Figure 2-13. ECU controls
Change 7
2-21/1(2-22 blank)
TM 55-1520-234-10
Section XI. ELECTRICAL POWER SUPPLY AND DISTRIBUTION SYSTEM
2-54. DC and AC Power Distribution.
Figure 2-14 depicts the general schematic of the dc
and ac power distribution system. The dc power is
supplied by the battery, starter-generator, or the external
power receptacle. The 115 Vac power is supplied by the
main or standby inverters. The 26 Vac power is
supplied by the 28 Vac transformer.
2-55. Battery.
The battery (figure 2-1) supplies 24 Vdc power to
the power distribution system when the starter-generator
and the external power receptacle are not in operation.
2-56. Starter-Generator.
The starter-generator (rated 300 amps) is mounted
on and driven by the engine. The starter-generator
supplies 28 Vdc power to the power distribution system
and recharges the battery. Avoid continuous operation
above 200 amps to prevent heat damage to startergenerator.
When the switch is released, it will return to OFF. The
OFF position isolates the generator from the system.
The circuit is protected by the GEN BUS RESET and
GEN FIELD circuit breaker.
c. Nonessential Bus Switch. The pilot NONESS
switch (figure 2-15) NORMAL position permits the
nonessential bus to receive 28 Vdc power from the
starter-generator. The MANUAL position permits the
nonessential bus to receive dc power from the battery.
d. DC Circuit Breaker Panel. The pilot ac circuit
breakers (figure 2-16) in the "pushed-in" position provide
circuit protection for the 28 Vdc operated equipment.
The breakers in the "pulled-out" position deactivate the
circuit. The breakers will "pop out" automatically in the
event of a circuit overload. Each breaker is labeled for
the particular circuit it protects. Each applicable breaker
is listed in the paragraph describing the equipment it
protects.
NOTE
Some armament circuit breakers may
be toggle type.
2-57. External Power Receptacle.
The external power receptacle (figure 2-1) transmits
the ground power unit 28 Vdc power to the power
distribution system. A 7.5 KW GPU is recommended for
external starts.
2-58. Gunner Electrical Power Control.
The gunner ELEC PWR-EMER OFF switch (figure
2-10) in the ELEC PWR position permits the pilot to
control the electrical system. The switch in the EMER
OFF position deactivates the electrical system and
negates the pilot controls.
2-59. Pilot DC Power Indicators and Controls.
a. Battery Switch. The pilot BAT switch (figure 215) ON position permits the battery to supply 24 Vdc to
the power distribution system or permits the battery to
be charged by the starter-generator. The OFF position
isolates the battery from the system.
b. Generator Switch. The pilot GEN switch (figure
2-15) ON position permits the starter-generator to supply
28 Vdc power to the power distribution system and to
charge the battery. The RESET position will reset the
starter-generator.
Change 30
e. Volt-Ammeter Indicator.
The pilot indicator
(figure 2-4) simultaneously displays the voltage and
amperage of dc power being supplied to the power
distribution system. The indicator right scale displays
the volts. The left scale displays the amps. The circuit
is powered by the 28 Vdc essential bus and protected by
the DC VOLTMETER circuit breaker.
f. Generator Caution Lights. The pilot and gunner
DC GENERATOR caution lights (figure 2-18) will
illuminate when the dc generator fails.
g. External Power Receptacle Caution Light. The
pilot EXTERNAL POWER caution light (figure 2-18) will
illuminate when the external power receptacle door is
open.
2-60. AC Power Indicators and Controls.
a. Inverter Switch. The pilot INV switch (figure 215) MAIN position selects the main
2-23
TM 55-1520-234-10
Figure 2-14. DC and AC power distribution (Sheet 1 of 2)
Change 7
2-24
TM 55-1520-234-10
Figure 2-14. DC and AC power distribution (Sheet 2 of 2)
Change 30
2-25
TM 55-1520-234-10
inverter. It is powered by the 28 Vdc essential bus and
protected by the INV MAIN circuit breaker. The STBY
position selects the standby inverter. It is powered by
the 28 Vdc essential bus and protected by the INV
STBY circuit breaker. The OFF position deactivates the
MAIN and STANDBY inverter circuits.
b. AC Circuit Breaker Panel. The pilot ac circuit
breakers (figure 2-16) in the "pushed-in" position provide
circuit protection for the 28 Vac and 115 Vac operated
equipment. The breakers in the "pulled-out" position
deactivate the circuit. The breakers will "pop out"
automatically in the event of a circuit overload. Each
breaker is labeled for the particular circuit it protects.
Each applicable breaker is listed -in the paragraph
describing the equipment it protects.
NOTE
Some armament circuit breakers may
be toggle type.
c. AC Failure Caution Light.
The pilot INST
INVERTER caution light (figure 2-18) will illuminate
when the inverter in use fails or when the INV switch is
in the OFF position.
Figure 2-15. Pilot electrical power panel
Change 7
2-26
TM 55-1520-234-10
NOTE
Armament circuit breakers indicated by asterisk may be toggle or push-pull type.
Figure 2-16. Circuit breaker panels
Change 30
2-27
TM 55-1520-234-10
Section XII. LIGHTING
2-61. Position Lights
a. Standard Position Lights.
(1) General. The position lights consist of the
right wing green light, left wing red light, and the two
tailboom white lights (figure 2-1).
The lights are
powered by the 28 Vdc nonessential bus and protected
by the POS LTS circuit breaker.
(2) Operation.
The pilot POSITION LTS
(FLASH) OFF/STEADY switch (figure 2-17) FLASH
position flash the four lights off and on. The STEADY
position illuminates the four lights continuous, The OFF
position deactivates the four lights. The pilot POSITION
LTS (BRT/DIM) switch (figure 2-17) controls the four
lights brightness.
b. NVG Position Lights.
(1) General.
A covert lighting system,
consisting of five infrared NVG position lights, has been
provided for use during multi-ship night vision goggle
(NVG) operations. The lights are mounted adjacent to
the standard position lights and at the top of the vertical
fin (figure 2-1). The lights are powered by the dc
nonessential bus and protected by the NVG POS LTS
circuit breaker (figure 2-16).
(2) Operation. The NVG POS LTS (OFF/
five position) rotary switch (figure 2-4) controls the
operation of the NVG position lights.
Position 1
activates the lights at minimum intensity. The intensity
may be increased incrementally by rotating the switch
toward BRT. The OFF position deactivates the five
NVG position lights.
Figure 2-17. Pilot lights control panel
2-63. Searchlight.
a. General.
The searchlight (figure 2-1) is
powered by the 28 Vdc essential bus and protected by
the SEARCH LT PWR circuit breaker. The searchlight
control is 28 Vdc nonessential bus powered and
protected by the SEARCH CONT circuit breaker.
b. Operation.
(1) Searchlight Switch. The pilot SL switch
figure 2-4) ON position illuminates the light. The OFF
position deactivates the light. The STOW position
retracts the light into the fuselage well.
(2) Searchlight Control Switch.
The pilot
SEARCH CONT switch (figure 2-4) EXT position
extends the light from the fuselage well and moves it
forward. RETR position moves the light aft. The L/R
position moves the light left and right.
2-62. Anti-Collision Light.
2-63A. Skid Landing Light.
a. General. The anti-collision light (figure 2-1) is
powered by the 28 Vdc nonessential bus and protected
by the ANTI-COLL LTS circuit breaker.
b. Operation. The pilot ANTI-COLL LT switch
(figure 2-17) ON position illuminates the anti-collision
light. The OFF position deactivates the light.
Change 19
a. General. A fixed landing light is installed on the
left side of the aircraft attached to the forward landing
gear crosstube (figure 2-1). This light provides a white
light capability for use during night operation without
NVG. The landing light is powered by the dc essential
bus and protected by the SKID LDG LT circuit breaker.
2-28
TM 55-1520-234-10
b. Operation. The SKID LDG LT switch (figure 24) ON position illuminates the light. The OFF position
deactivates the light. The elevation of the landing light
beam is adjustable on the ground only.
NOTE
The IR filter and 150 watt bulb may
be Installed on the skid landing light
with the 450 watt bulb Installed In the
standard searchlight housing. This
configuration provides a slewable
white searchlight and a groundadjustable IR light.
2.64. Cockpit Utility Lights.
a. General. The pilot (two) and the gunner (one)
utility lights are powered by the 28 Vdc essential bus
and protected by the COCKPIT LT circuit breaker. The
lights are supplied in various configurations.
All
configurations have on/off and bright/dim capabilities
and provide NVG compatible light.
Adjustable
extensions have been provided for pilot (right) and
gunner utility lights.
An alternate light bracket is
provided for the pilot (left) utility light.
b. Operation. The pilot gunner determines the
configuration of his light and operates it accordingly.
Cockpit (map) lights must be in the blue-green mode
when operating in the night vision environment to
prevent light blindness; and in the white mode when
operating in the normal environment to provide proper
visibility.
2-65. Pilot Station Lighting.
a. Pilot Instrument Panel Lighting.
(1) General. The panel is illuminated by
hooded type and instrument built-in lights. The lights
are powered by the 28 Vdc essential bus and protected
by the PILOT INSTR LT circuit breaker.
(2) Normal Lighting Operation.
The pilot
INSTR LTS rheostat knob (figure 2-17) OFF position
deactivates the lights. The between OFF and BRT
positions controls the brightness of the instrument builtin lights. The hooded lights have no brightness control.
NOTE
The cockpit utility light Ions selector
must be placed In the "white"
position In order to provide adequate
Illumination with the NVG filters
Installed.
Change 19
2-28A/(2-28B blank)
TM 55-1520-234-10
(3) Night
Vision
Goggle
Lighting
Operation.
A two position (NVG/OFF) switch is
provided (figure 2-17) to activate the night vision
system. The NVG position activates the night vision
feature of the system, and cockpit is lighted to be
compatible with night vision goggles. The OFF position
deactivates the night vision feature, and normal lighting
conditions are restored. Intensity of NVG lighting is
accomplished by use of CONSOLE LTS rheostat knob.
b. Pilot Consoles and Collective Stick Switchbox
Lighting.
(1) General. The console is illuminated by
edgelight panels and equipment built-in lights. The
switchbox is illuminated by one hooded type light. The
lights are powered by the 28 Vdc essential bus and
protected by the PILOT INSTR LT circuit breaker.
(2) Operation.
The pilot CONSOLE LTS
rheostat knob (figure 2-17) OFF position deactivates the
light. The between OFF and BRT positions control the
brightness of the console edgelight panels and
equipment built-in lights. The switchbox hooded light
has no brightness control.
2-66. Gunner Station Lighting.
a. General.
The gunner instrument panel is
illuminated by hooded type and instrument built-in lights.
The miscellaneous control panel (figure 2-10) and the
armament control panel (Chapter 4) are illuminated by
edgelight panels. The magnetic compass (figure 2-5) is
illuminated by one hooded type light. The lights are
powered by the 28 Vdc essential bus and protected by
the GUNNER INSTR LT circuit breaker.
b. Normal Lighting Operation. The gunner INSTR
LTS rheostat knob (figure 2-10) OFF position
deactivates the lights. The between OFF and BRT
positions control the brightness of the instrument built-in
lights and the edgelight panels. The hooded lights have
no brightness control.
c. Night Vision Goggle Lighting Operation. A two
position (NVG/OFF) switch is provided (figure 2-10) to
activate the night vision system. The NVG position
activates the night vision feature of the system, and the
cockpit is lighted to be compatible with night vision
goggles. The OFF position deactivates the night vision
feature and normal lighting conditions are restored.
Intensity of NVG lighting is accomplished by use of
INST LTS rheostat knob.
Section XIII. FLIGHT INSTRUMENTS
2-67. Airspeed Indicators.
2-69. Attitude Indicators.
The pilot and gunner airspeed indicators (figures 2-4
and 2-7) display the helicopter indicated airspeed (IAS)
in knots. The IAS is obtained by measuring the
difference between impact air pressure from the pilot
tube (figure 2-1) and the static air pressure from the
static ports (figure 2-1).
NOTE
IAS below approximately 25 KIAS is
inaccurate due to rotor downwash.
2-68. Pressure Altimeters.
The pilot and gunner altimeters (figures 2-4 and 2-7)
display the helicopter height above sea level in feet.
The pilot and gunner attitude indicators (figures 2-4
and 2-7) display the helicopter pitch and roll attitudes in
relation to the earth. Pitch attitude is displayed by the
motion of the sphere with respect to the miniature
airplane. Roll attitude is displayed by the motion of the
roll pointer with respect to the fixed roll scale. The
sphere can be adjusted to zero indication by the pitch
trim knob. The power OFF flag is out of view when the
indicator is energized. A power failure will cause the
OFF flag to appear. The circuit is powered by the 115
Vac system and protected by the ATTD IND PLT and
ATTD IND GUNNER circuit breakers.
2-70. Turn and Slip Indicator.
The pilot turn and slip indicator (4 MIN TURN)
(figure 2-4) displays the helicopter slip condition,
direction of turn and rate of turn. The ball displays
Change 30 2-29
TM 55-1520-234-10
the slip condition. The pointer displays the direction and
rate of the turn. The circuit is powered by the 28 Vdc
essential bus and protected by the TURN & SLIP IND
circuit breaker.
2-71. Vertical Velocity Indicator.
The pilot vertical velocity indicator (figure 2-4)
displays the helicopter ascent and descent speed in feet
per minute. The indicator is actuated by the rate of
atmospheric pressure change.
prevent light blindness; and open when operating in the
normal environment to provide proper visibility.
b. Caution Panels (figure 2-18).
(1) Caution Panel Lights.
The pilot and
gunner caution panels lights illuminate to identify
specific fault conditions. The caution light lettering is
readable only when the light illuminates. The light will
remain illuminated until the fault condition is corrected
or the light panel is rotated in the caution panel.
2-72. Free Air Temperature (FAT) Indicator.
The pilot FAT indicator (figure 24) displays the
outside air temperature in celsius degrees.
2-73. Magnetic (Standby) Compass.
The gunner magnetic compass (figure 2-5) displays
the magnetic heading of the helicopter. A compass
correction card is attached to the compass.
(2) Test Reset and Test Switches. The pilot
caution panel has a TEST/RESET switch. The gunner
caution panel has a TEST switch. Momentarily placing
the pilot switch in the TEST position will cause both
MASTER CAUTION lights to illuminate. All caution
lights on the pilot's panel and all caution lights except
two spares on the gunner's caution panel will illuminate.
Momentarily placing the gunner's switch in the TEST
position will illuminate all lights on the gunner's caution
panel.
2-74. Radio Aids to Navigation.
The FM radio, automatic directional finder, course
indicator, and radio magnetic indicator are radio aids to
navigation and are covered in Chapter 3.
2-75. Master Caution System.
a. Master Caution Lights. The pilot and gunner
master CAUTION lights (figures 2-4 and 2-7) illuminate
when fault conditions occur. This illumination alerts the
pilot and gunner to check his caution panel for the
specific fault condition. The blue-green cover must be
closed when operating in the night vision environment to
(3) Bright-Dim Switches. The caution panels
have a BRIGHT-DIM (pilot), BRT-DIM (gunner) switch to
control the brightness of the panel caution lights and the
master CAUTION lights. This switch will not function if
the pilot CONSOLE LTS rheostat (figure 2-17) or the
gunner INST LTS rheostat (figure 2-10) is in the OFF
position. The caution panel lights and the master
CAUTION lights will be at full brightness when the
pilot/gunner rheostats are in the OFF position.
c. Electrical Circuit. The master caution system is
powered by the 28 Vdc essential bus and protected by
the CAUTION LTS circuit
Change 30 2-30
TM 55-1520-234-10
CAUTION PANEL WORDING
FAULT CONDITIONS
ENGINE OIL PRESS
Engine oil pressure below operating minimum (25 psi).
* ENGINE OIL BYPASS
Engine oil bypass switch OFF Oil system level down 3.8 quarts from full.
Engine oil bypass switch AUTOMATIC Oil system level down 3.8 quarts from full and
bypassing cooler.
Forward fuel boost pump pressure low (below 5 psi).
Aft fuel boost pump pressure low (below 5 psi).
One side and/or both sides of engine fuel pump
producing low pressure.
Low fuel quantity.
Fuel filter is partially obstructed.
Governor switch in emergency position.
Transmission oil bypassing oil cooler.
Transmission oil pressure is below minimum (below 30 psi).
Transmission oil temperature is at or above red line.
System 1 hydraulic pressure is low.
System 2 hydraulic pressure is low.
AC power lost.
DC generator has failed.
External power receptacle door open.
Metal particles in transmission, engine. 42 degree gearbox.
or 90 degree gearbox.
Mode 4 is inoperative or has failed to reply to a Mode 4
interrogation.
209075-271G
* FWD FUEL BOOST
* AFT FUEL BOOST
ENG FUEL PUMP
10% FUEL
FUEL FILTER
GOV EMER
* XMSN OIL BYPASS
XMSN OIL PRESS
XMSN OIL HOT
HYD PRESS #1
HYD PRESS #2
* INST INVERTER
DC GENERATOR
* EXTERNAL POWER
CHIP DETECTOR
* IFF
Figure 2-18. Pilot and gunner caution panels
Change 19 2-31
TM 55-1520-234-10
2-76. Engine Fire Detection System.
(1) For rotor rpm of 300-310 and engine rpm
of 6100-6300 (Low Warning).
a. General. The system provides the pilot and
gunner with a visual indication of a fire in the engine
compartment. The system is powered by the 28 Vdc
essential bus and protected by the FIRE DET circuit
breaker.
b. Fire Detector Light. The FIRE light (figures 2-4
and 2-7) illuminates when sensing elements detect
excessive heat in the engine compartment. The sensing
elements are attached to the tail rotor driveshaft tunnel,
fire wail and heat shield. The blue-green cover must be
closed when operating in the night vision environment to
prevent light blindness; and open when operating in the
normal environment to provide proper visibility.
c. Fire Detector Test Switch. Holding the pilot
FIRE DETECTOR TEST switch (figure 2-4) in the ON
position will cause the FIRE light to illuminate. This
illumination indicates that the system is operational.
(2) Loss of signal (circuit failure) from both
rotor tachometer generator and power turbine
tachometer generator.
NOTE
It is possible to have an unmodified
warning system in the aircraft. On
unmodified warning systems, an
audio signal will be heard if either
rotor or engine RPM drops below low
limits.
c. RPM Warning Light. The pilot RPM light (figure
2-4) illuminates to provide a visual warning of high or
low rotor rpm or low engine rpm. The blue-green cover
must be closed when operating in the night vision
environment to prevent light blindness; and open when
operating in the normal environment to provide proper
visibility.
2-77. RPM HIGH-LOW LIMIT WARNING SYSTEM.
The system provides an immediate warning to check
instruments for high or low rotor rpm or low engine rpm.
The audio warning will be heard in the pilot and gunner
headsets. The audio is a varying oscillating frequency
starting low and building up to a high pitch, on for 0.85
second interval, then off for 1.25 second, then repeating
cycle. The light warning and audio warning functions
when the following rpm conditions exist:
a. Warning light only:
d. RPM Switch-Low Audio. The pilot RPM switch
(figure 2-9) OFF position prevents audio warning from
functioning for engine starting when the audio might be
objectionable.
The switch automatically resets to
WARNING position when the engine and rotor reach
normal rpm.
e. Electrical Circuit.
The RPM high-low limit
warning system is powered by 28 Vdc essential bus and
protected by the RPM WARN circuit breaker.
2-77.1. Low G Warning System.
(1) For rotor rpm of 329-339 (High Warning).
(2) For rotor rpm of 300-310 (Low Warning).
(3) For engine rpm of 6100-6300 (Low
Warning).
(4) Loss of signal (circuit failure) from either
rotor tachometer generator or power turbine tachometer
generator.
b. Warning
combination:
light
and
audio
warning
The system provides an audio/visual warning to
enable the pilot to recover and avoid entering a low G
flight condition. The light and audio are activated when
the helicopter enters a 0.55g flight condition. A counter,
located under the left pilot console, will record a low G
encounter each time the helicopter experiences a 0.45g
or less flight condition. The warning light is located on
the right side of the pilot instrument panel. Pressing the
light will test the lamp and audio. The circuit is powered
by the essential bus and is protected by the LGW circuit
breaker located in the aft electrical compartment.
signal
Change 30 2-32
TM 55-1520-234-10
Section XIV. SERVICING, PARKING, AND MOORING
2-78. Servicing.
a. Servicing Diagram. Refer to figure 2-19.
b. Approved Military Fuels, Oils Fluids, and Unit
Capacities. Refer to figure 2-20.
2-78A. Fuel System Servicing.
WARNING
Servicing personnel shall comply
with all safety precautions and
procedures specified in FM 10-68
Aircraft Refueling field manual.
CAUTION
Ensure that servicing unit pressure
is not above 125 psi while refueling.
a. Refer to Figure 2-20 for fuel tank capacities.
b. Refer to Figure 2-21 for approved fuel.
c. The Helicopter may be serviced by any of the
methods described as follows:
(1) Closed Circuit Refueling (Power Off).
(a) Refer to Figure 2-19 for fuel filler
location.
(b) Assure that fire guard is in position
with fire extinguisher.
(c) Ground servicing unit to ground
stake.
(d) Ground servicing unit to Helicopter.
(e) Ground fuel nozzle to ground
receptacle located adjacent to fuel receptacle on
helicopter.
(f) Remove fuel filler cap, and assure
that refueling module is in locked position.
(g) Remove nozzle cap and insert
nozzle into fuel receptacle and lock into position.
(h) Activate flow control handle to ON
or FLOW position. Fuel flow will automatically shut off
when fuel cell is full. Just prior to normal shut off, fuel
flow may cycle several times, as maximum fuel level is
reached.
(i) Assure that flow control handle is in
OFF or NO FLOW position and remove nozzle.
(j) Replace fuel nozzle cap.
(k) Replace fuel filler cap.
(l) Disconnect fuel nozzle ground.
(m) Disconnect ground from helicopter
to servicing unit.
(n) Disconnect servicing unit ground
from ground stake.
(o) Return
fire
extinguisher
to
designated location.
(2) Gravity or Open-Port Refueling (Power
Off.
(a) Refer to Figure 2-19 for fuel filler
location.
(b) Assure that fire guard is in position
with fire extinguisher.
(c) Ground servicing unit to ground
stake.
(d) Ground servicing unit to Helicopter.
(e) Ground fuel nozzle to ground
receptacle located adjacent to fuel receptacle on
helicopter.
(f) Remove fuel filler cap.
(g) Using latch tool attached to filler
cap cable open refueling module, if equipped with
closed circuit receptacle.
(h) Remove nozzle cap and insert
nozzle into fuel receptacle.
(i) Activate flow control handle to ON
or FLOW position. Fuel flow will automatically shut off
when fuel cell is full.
(j) Assure that flow control handle is in
OFF or NO FLOW position and remove nozzle.
(k) Replace fuel nozzle cap.
(l) Close refueling module by pulling
cable until latch is in locked position, if equipped with
closed circuit receptacle.
(m) Replace fuel filler cap.
(n) Disconnect fuel nozzle ground.
(o) Disconnect ground from helicopter
to servicing unit.
(p) Disconnect servicing unit ground
from ground stake.
(q) Return
fire
extinguisher
to
designated location.
(3) RAPID (HOT) Refueling (Closed Circuit).
(a) Before RAPID Refueling.
1. Throttle - Idle.
2. FORCE TRIM switch - FORCE
TRIM.
Change 19 2-33
TM 55-1520-234-10
WARNING
In case of helicopter fire, observe fire
emergency procedures in Chapter 9.
(d) After refueling, the pilot shall be
advised by the refueling crew or other crewmembers of
the following:
(b) During RAPID Refueling.
A
crewmember shall observe the refueling operation
(performed by authorized refueling personnel) and stand
fire guard as required. One crewmember shall remain
in the helicopter to monitor controls. Only emergency
radio transmission should be made during Rapid
refueling.
(c) Use same procedure as for Power
Off Refueling, Para (1).
(d) After refueling, the pilot shall be
advised by the refueling crew or other crewmembers of
the following:
1. Fuel cap secured.
2. Grounding cables removed.
(4) RAPID (HOT) GRAVITY Refueling.
(a) Before RAPID Refueling.
1. Throttle - Idle.
2. FORCE TRIM switch- FORCE
TRIM.
WARNING
In case of helicopter fire, observe fire
emergency procedures in Chapter 9.
1. Fuel cap secured.
2. Grounding cables removed.
2-79. Approved Commercial Fuels, Oils, and Fluids.
a. Fuels. Refer to figure 2-21.
b. Oils. Refer to figure 2-22.
c. Fluids. Refer to figure 2-23.
2-80. Types and Use of Fuels.
a. Fuel Types.
(1) Army Standard Fuels. These are the
Army-designated primary fuels adopted for worldwide
use, and are the only fuels available in the Army supply
system.
(2) Alternate Fuels. These are fuels which
can be used continuously when Army standard fuel is
not available, without reduction of power output. Power
setting adjustments and increased maintenance may be
required when an alternate fuel is used.
(3) Emergency Fuels. These are fuels which
can be used if Army standard and alternate fuels are not
available. Their use is subject to a specific time limit.
b. Use of Fuels.
(b) During RAPID Refueling.
A
crewmember shall observe the refueling operation
(performed by authorized refueling personnel) and stand
fire guard as required. One crewmember shall remain
in the helicopter to monitor controls. Only emergency
radio transmission should be made during Rapid
refueling.
(c) Use same procedure as for Power
Off Refueling, Para (1).
WARNING
During RAPID GRAVITY Refueling,
exercise extreme caution to prevent
fuel splashing from fuel cell or fuel
nozzle. Any fuel leakage could be
extremely hazardous if ingested into
engine air intake.
(1) There is no special limitation on the use of
Army standard fuel, but certain limitations are imposed
when alternate or emergency fuels are used. For the
purpose of recording, fuel mixtures shall be identified as
to the major component of the mixture except when the
mixture contains leaded gasoline. A fuel mixture which
contains over 10 percent leaded gasoline shall be
recorded as all leaded gasoline. The use of any fuels
other than standard or alternate shall be recorded as all
leaded gasoline. The use of any emergency fuels will
be recorded in the FAULTS/REMARKS column of DA
Form 2408-13, Aircraft Maintenance and Inspection
Record, noting the type of fuel, additives, and duration
of operation.
Change 13 2-34
TM 55-1520-234-10
(2) The use of kerosene fuels (JP-5-type) in
turbine engines dictates the need for observance of
special precautions. Both ground starts and air restarts
at low temperature may be more difficult due to low
vapor pressure. Kerosene fuels having a freezing point
of - 40 degrees F (- 40 degrees C) limit the maximum
altitude of a mission to 28,000 feet under standard day
conditions. Those having a freezing point of -67
degrees F (-53 degrees C) limit the maximum altitude of
a mission to 33,000 feet under standard day conditions.
(3) Mixing of Fuel in Helicopter Tanks. When
changing from one type of authorized fuel to another, for
example JP-4 to JP-5, it is not necessary to drain the
helicopter fuel system before adding the new fuel.
(4) Fuels may be used when MIL-T-5624
fuels are not available. This usually occurs during cross
country flights where helicopters using NATO F-44 (JP5) are refueled with NATO F-40 (JP-4) or commercial
ASTM type B fuels. Whenever this condition occurs,
the engine operating characteristics may change in that
lower operating temperature, slower acceleration, lower
engine speed, easier starting, and shorter range may be
experienced. The reverse is true when changing from
F-40 (JP-4) fuel to F-44 (JP-5) or commercial ASTM
type A-1 fuels. Specific gravity adjustments in fuel
controls and flow dividers shall be set for the type of fuel
used. Most commercial turbine engines will operate
satisfactorily on either kerosene or JP-4 type fuel.
However, the difference in specific gravity may possibly
require fuel control adjustments; if so, the
recommendations of the manufacturers of the engine
and air frame are to be followed.
2-80A. Fuel Sample Waiting Time.
The total waiting time before taking a fuel sample is 15
minutes per foot of tank depth for AVGAS and one hour
per foot of tank depth for jet (JP) fuels.
2-81. Deleted.
Change 19 2-34A
TM 55-1520-234-10
Figure 2-19. Servicing diagram (typical)
Change 19
2-34B
TM 55-1520-234-10
SYSTEM
SPECIFICATION
Fuel
NOTE
MIL-5624 (JP-4)
MIL-T-5624 (JP-4)
1
CAPACITY
260 U. S. Gals. Usable
262 U. S. Gals. Total
Oil
Engine
MIL-L-7808
MIL-L-23699
2, 4
3, 4
Transmission
MIL-L-7808
MIL-L-23699
2, 4
3, 4
42°Gearbox
MIL-L-7808
MIL-L-23699
2, 4
3, 4
90°Gearbox
MIL-L-7808
MIL-L-23699
2, 4
MIL-H-5606
MIL-H-83282
5.7
6, 7
System No. 2
MIL-H-5606
MIL-H-83282
5, 7
6, 7
Reservoir No. 1 & 2
MIL-H-5606
MIL-H-83282
5, 7
Hydraulic
System No. 1
NOTE:
1. MIL-T-5624 (JP-4) NATO code is F-40.
Alternate fuel is MIL-T-5624 (JP-5) (NATO F-44).
Emergency fuel is MIL-G-5572 (Any AVGAS) (NATO F-12, F-18, F-22). The helicopter shall not be flown when
emergency fuel has been used for a total cumulative time of 50 hours.
2. MIL-L-7808 NATO code is 0-148.
For use in ambient temperatures below minus 32°C/25°F.
May be used when MILL23699 oil is not available.
3. MIL-L-23699 NATO code is 0-156.
For use in ambient temperatures above minus 32°C/25°F.
CAUTION
Under no circumstances shall MIL-L-23699 oil be used in ambient temperatures below minus
32°C/25°F.
4. It is not advisable to mix MIL-L-7808 and MIL-L-23699 oils, except during an emergency. If the oils are mixed,
the system shall be flushed within six hours and filled with the proper oil. An entry on DA Form 2408-13 is
required when the oils are mixed.
5. MIL-H-5606 NATO code is H-515.
For use in ambient temperatures below minus 40°C/40°F.
6. For use in ambient temperatures above minus 40°C/40°F.
7. It is not advisable to mix MIL-H-5606 and MIL-H-83282 fluids, except during an emergency. An entry on DA
Form 2408-13 is required when the fluids are mixed. When changing from MIL-H-5606 to MIL-H-83282, not
more than two percent of MIL-H-5606 may be present in the system.
Figure 2-20. Approved military fuels, oils, fluids, and unit capacities
Change 19 2-35
TM 55-1520-234-10
APPROVED DOMESTIC COMMERCIAL FUELS (SPEC. ASTM-D-1655-70)
MANUFACTURER'S DESIGNATION
MANUFACTURER'S
NAME
American Oil Co.
Atlantic Richfield
Richfield Div
B. P. Trading
Caltex Petroleum Corp.
Cities Service Co.
Continental Oil Co.
Gulf Oil
EXXON Co, USA
Mobil Oil
Phillips Petroleum
Shell Oil
Sinclair
Standard Oil Co
Chevron
Texaco
Union Oil
COUNTRY
Belgium
Canada
Denmark
France
Germany (West)
Greece
Italy
Netherlands
Norway
Portugal
Turkey
United Kingdom
(Britain)
JET B - JP4
NATO F40
JET A - JP4
NATO NONE
American JP-4
Aerojet B
American Type A
Aerojet A
Richfield A
JET A-1 - JP5
NATO F-34
Aerojet A-1
Richfield A-1
B.P.A.T.K.
Caltex Jet A-1
B.P.A.T.G.
Caltex Jet B
Conoco JP-4
Gulf Jet B
EXXON Turbo Fuel B
Mobil Jet B
Philjet JP4
Aeroshell JP4
Chevron B
Texaco Avjet B
Union JP4
CITGO A
Conoco Jet-50
Gulf Jet A
EXXON A
Mobil Jet A
Philjet A-50
Aeroshell 640
Superjet A
Jet A Kerosine
Chevron A-50
Avjet A
76 Turbine Fuel
APPROVED FOREIGN COMMERCIAL FUELS
JET B - JP4
NATO F-40
BA-PF-2B
3GP-22F
JP-4 MIL-T-5624
Air 3407A
VTL-9130-006
JP-4 MIL-T-5624
AA-M-C-1421
JP-4 MIL-T-5624
JP-4 MIL-T-5624
JP-4 MIL-T-5624
JP-4 MIL-T-5624
D. Eng RD 2454
Conoco Jet-60
Gulf Jet A-1
EXXON A-1
Mobil Jet A-1
Aeroshell 650
Superjet A-1
Jet A-1 Kerosine
Chevron A-1
Avjet A-1
JET A - JP5
NATO NONE
3-6P-24e
UTL-9130-007/UTL 9130-010
AMC-143
D. Eng RD 2493
D. Eng RD 2498
NOTE:
Anti-icing and Biocidal Additive for Commercial Turbine Engine Fuel - The fuel system icing inhibitor shall conform to
MIL-I-27686. The additive provides anti-icing protection and also functions as a biocide to kill microbial growths in
helicopter fuel systems. Icing inhibitor conforming to MIL-I-27686 shall be added to commercial fuel, not containing an
icing inhibitor, during refueling operations, regardless of ambient temperatures. Refueling operations shall be
accomplished in accordance with accepted commercial procedures. Commercial product "PRIST" conforms to MIL-l27686.
Figure 2-21. Approved commercial fuels - equivalents for JP4 and JP5
All data on page 2-36A/2-36B, including Figure 2-21A is deleted.
Change 19 2-36
TM 55-1520-234-10
Figure 2-21A. Receiver and Cap Assembly
Change 13 2-36A/(2-36B blank)
TM 55-1520-234-10
APPROVED DOMESTIC COMMERCIAL OILS FOR MIL-L-7808
MANUFACTURER'S NAME
MANUFACTURER'S DESIGNATION
American Oil and Supply Co.
Humble Oil and Refining Co.
Mobile Oil Corp.
PQ Turbine Oil 8365
ESSO/ENCO Turbo Oil 2389
RM-184A/RM-201A
CAUTION
Do not use Shell Oil Co., part No. 307, qualification No. 7D-1 oil (MIL-L-7808). It can be harmful
to seals made of silicone.
APPROVED DOMESTIC COMMERCIAL OILS FOR MIL-L-23699
MANUFACTURER'S NAME
MANUFACTURER'S DESIGNATION
American Oil and Supply Co.
PQ Turbine Lubricant 5247/
6423/6700/7731/8878/9595
Brayco 899/899-G/899-S
Castrol 205
Jet Engine Oil 5
STO-21919/STO-21919A/STD 6530
HATCOL 3211/3611
Bray Oil Co.
Castrol Oil Co.
Chevron International Oil Co., Inc.
Crew Chemical Corp.
W. R. Grace and Co. (Hatco
Chemical Div.)
Humble Oil and Refining Co.
Turbo Oil 2380 (WS-6000)/2395
(WS-6459)/2392/2393
RM-139A/RM-147A/Avrex S
Turbo 260/Avrex S Turbo 265
Royco 899 (C-915)/899SC/
Stauffer Jet II
Aeroshell Turbine Oil 500
Aeroshell Turbine Oil 550
Chevron Jet Engine Oil 5
Stauffer 6924/Jet II
SATO 7377/7730. TL-8090
Mobile Oil Corp.
Royal Lubricants Co.
Shell Oil Co., Inc.
Shell International Petroleum Co., Ltd.
Standard Oil Co., of California
Stauffer Chemical Co.
Texaco, Inc.
APPROVED FOREIGN COMMERCIAL OILS FOR MIL-L-7808
Data not available at this time.
APPROVED FOREIGN COMMERCIAL OILS FOR MIL-L-23699
Data not available at this time.
Figure 2-22. Approved commercial oils - equivalents for MIL-L-7808 and MIL-L-23699 oils
2-37
TM 55-1520-234-10
APPROVED DOMESTIC COMMERCIAL FLUIDS FOR MIL-H-5606
MANUFACTURER'S NAME
MANUFACTURER'S DESIGNATION
American Oil and Supply Co.
"PO" 4226
Bray Oil Co.
Brayco 757B
Brayco 756C
Brayco 756D
Castrol Oils, Inc.
Hyspin A
Humble Oil and Refining Co.
Univis J41
Mobile Oil Corp.
Aero HFB
Pennsylvania Refining Co.
Petrofluid 5606B
Petrofluid 4607
Royal Lubricants Co.
Royco 756C/D
DS-437
Shell Oil Co.
XSL 7828
Standard Oil Co., of California
PED 3565
PED 3337
Texaco, Inc.
TL-5874
Stauffer Chemical Co.
Aero Hydroil 500
Union Carbide Chemical Co.
YT-283
Union Carbide Corp.
FP-221
APPROVED DOMESTIC COMMERCIAL FLUIDS FOR MIL-H-83282
Data not available at this time.
APPROVED FOREIGN COMMERCIAL FLUIDS FOR MIL-H-5606
Data not available at this time.
APPROVED FOREIGN COMMERCIAL FLUIDS FOR MIL-H-83282
Data not available at this time.
Figure 2-23. Approved commercial fluids - equivalents for MIL-H-5606 and MIL-L-83282 fluids
All data on page 2-39/2-40, including Figure 2-24 is deleted.
Change 19 2-38
TM 55-1520-234-10
Figure 2-24. Ground handling equipment, covers, rotor tiedowns, and mooring diagram
Change 9 2-39/(2-40 blank)
TM 55-1520-234-10
CHAPTER 3
AVIONICS
NOTE
In all radio operations, it is assumed
the crew has applied battery or GPU
power and circuit breakers are
pushed in.
3-1. General.
This chapter covers the electronic equipment
configuration installed in Army Model AH-1S helicopter.
It includes a brief description of the electronic
equipment, its technical characteristics, capabilities, and
location. This chapter also contains complete operating
instructions for all signal equipment installed in the
helicopter. For mission avionics equipment, refer to
Chapter 4, Mission Equipment.
NOTE
The terms "megahertz" and "kilohertz" have
replaced the terms "megacycle" and
"kilocycle". This chapter will use the terms
"megahertz" and "kilohertz" regardless of
the equipment markings.
3-2. Electronic Equipment Configuration.
The configuration consists of headset cordages,
keying switches, external interphone receptacles, and
the equipment listed in figure 3-1.
a. Headset Cordages.
The pilot cordage
connector is located to his left, outboard from his
collective control stick. The gunner cordage connector
is located aft of his cyclic stick and just forward of the
canted bulkhead.
b. Keying Switches. A hat type keying switch is
located on the pilot and gunner cyclic control stick grips.
The aft position of the switch keys the interphone. The
forward position of the switch keys the radio selected
with the transmit-interphone selector switch on the
signal distribution panel. A foot operated type keying
switch is located on the right side of the gunner floor.
The depressed position of the switch keys the radio or
interphone selected with the transmit-interphone
selector switch on the gunner signal distribution panel.
d. Power Supply. Refer to figure 2-14.
3-3. Signal Distribution Panel'.
a. Description. Two of the panels are installed in
the helicopter. The pilot panel is in the left console.
The gunner panel is on his floor forward of his seat. The
system is used for intercommunication and radio
control. It may be used in any one of three different
modes as determined by the setting of the switches and
controls on the panel. The three modes of operation
are: Two-way radio communication; radio receiver
monitoring; and intercommunication between the pilot,
gunner, and ground crew.
c. External Interphone Receptacles. A receptacle
is located in each wing tip behind a hinged access door.
Headset cordages (within-the-line keying switches) are
provided for adapting the headset to the receptacles.
b. Controls and Functions. Refer to figure 3-3.
c. Operating Procedures.
1. Transmit interphone selector switch As desired.
2. RECEIVERS switches - As desired.
3. Microphone switch - As desired.
4. VOL control - Adjust.
Change 9 3-1
TM 55-1520-234-10
NOMENCLATURE
COMMON NAME
USE
RANGE
Control. Intercommunication
Set C-1611 (*)/
AIC
Interphone
Control
Interphone for pilot
and gunner; integrates
all communication
equipment.
Stations within
helicopter.
Radio Set AN/
ARC-51BX
UHF Command
Radio
Two way voice
communication
Line of sight
Radio Set AN/
ARC-54 or AN/
ARC-131
FM Command
Radio
Two way voice
communication
and homing.
Line of sight
Indicator ID-48/
ARN
Course Indicator
FM homing
Communications
Security Equipment
TSEC/KY28
Voice Security
Equipment
In conjunction with
the FM radio set
to provide secure
two way voice
communications
Radio Set AN/
ARC-134
VHF Radio
Two way voice
communication
Line of sight
or 50 miles
average
conditions
Direction Finder
Set AN/ARN-83
ADF Set
Radio range
navigation
150 to 200
miles average
Gyromagnetic
Compass Set
AN/ASN-43
Compass Set
Navigation aid
Transponder Set
AN/APX-72
IFF Transponder
Radio
Transmit a special
coded reply for
radar interrogator
systems
Proximity Warning
Device
Proximity
Warning
Device
Provides warning of other
aircraft, equipped and using
PWD system to avoidance
of mid-air collision
Line of sight
Line of sight
209475-362C
Figure 3-1. Electronic equipment configuration
All data on page 3-3 including figure 3-2 deleted
Change 9 3-2
TM 55-1520-234-10
CONTROL
FUNCTION
RECEIVERS
switches 1 (FM),
2 (UHF), 3 (VHF).
and 4 (not used)
Turns audio from associated
receiver ON or OFF
INT switch
ON position enables operator to
hear audio from the interphone.
NAV switch
ON position enables operator
to monitor audio from the
navigation receiver.
VOL control
Adjusts audio on receivers
except NAV receivers.
Transmitinterphone
selector switch
Positions 1 (FM), 2 (UHF), 3
(VHF), 4 (not used) and INT
permits INT or selected
receiver-transmitter to transmit
and receive- The cyclic stick
switch or foot switch must be
used to transmit. PVT position
keys interphone for transmission.
205475-1003A
Figure 3-3. Signal distribution panel
3-4
TM 55-1520-234-10
Section I. COMMUNICATIONS
3-4. UHF Command Set.
3-5. FM Command Radio.
a. Description. The UHF set provides two-way
communication in 3500 channels of the UHF range. A
preset channel selector and 20 preset channels are
incorporated. Capabilities for monitoring or transmitting/
receiving UHF guard frequency are provided. The set is
controlled by the panel marked UHF mounted in the
pilot right hand console.
a. Description. The FM radio, AN/ARC-54 or
AN/ARC-131, is mounted in the pilot instrument panel.
Frequency range for the AN/ARC-54 is from 30.00 to
69.95 MHz. Frequency range for the AN/ARC-131 is
from 30.00 to 75.95 MHz. The set is used for two-way
communication. Homing to a known station can be
accomplished using the course indicator with this radio.
b. Controls and Functions. Refer to figure 3-4.
b. Controls and Functions. Refer to figure 3-5.
c. Operating Procedures.
c. Operating Procedures.
1.
2.
3.
4.
5.
6.
Mode selector switch - PTT or T/R.
Frequency - Select.
VOL control - Adjust.
SQUELCH control - CARR or as required.
Receiver switch No. 1 - Forward position.
Transmit interphone selector switch
Position No. 1.
7. Microphone switch - Press to transmit.
8. Homing - Mode selector switch HOME.
1. Function selector switch - T/R (T/R plus G
as required).
2. Mode selector switch - PRESET CHAN.
Allow set to warm up.
3. RECEIVERS switch No. 2 - Forward
position.
4. Frequency - Select.
5. SQ DISABLE switch - OFF.
6. VOL control - Adjust.
7. Transmit interphone selector switch
Position 2.
8. Microphone switch - Press to transmit.
9. Function selector switch - OFF.
NOTE
Signal frequencies at 62 MHz and
above produce false on-course
indications. Final home destination
will be achieved but route covered
may not be the most direct.
d. UHF Guard Frequency Operation. With radio in
operation, place the mode selector to the GD XMIT
position. The set will now transmit or receive frequency
243.0.
9. Mode selector switch - OFF.
NOTE
Do not transmit on emergency
(GUARD) frequency except when
under actual emergency conditions.
3-6. Course Indicator.
a. Description. The course indicator is located in
the pilot instrument panel. This indicator is used only
when the FM radio is operating in homing mode.
b. Indicators and Functions. Refer to figure 3-6.
3-5
TM 55-1520-234-10
CONTROL
1. Function Selector
OFF position
T/R position
T/R + G position
ADF position
2. Channel Indicator
FUNCTION
Applies power to radio and selects type of operation.
Removes operating power from the set.
Transmitter and main receiver ON.
Transmitter, main receiver and guard receiver ON.
Not used.
Indicates the frequency selected by the frequency controls.
3. Frequency Controls
Left-hand control
Center control
Right-hand control
4. Mode Selector
PRESET CHAN
position
MAN position
GD XMIT position
Selects the first two digits of desired frequency.
Selects the third digit of desired frequency.
Selects the fourth and fifth digits of the desired frequency.
Determines the manner in which the frequencies are selected
as follows:
Permits selection of one of 20 preset channels by means of
preset channel control.
Permits frequency selection by means of frequency controls.
Receiver-transmitter automatically tunes to guard channel
frequency.
5.
PRESET CHAN
Permits selection of any of 20 preset channels.
6.
SQ DISABLE switch
In the ON position squelch is disabled.
In the OFF position the squelch is operative.
7.
VOL Control
Controls the receiver audio volume.
8.
Preset Channel Indicator
control.
Indicates the preset channel selected by preset channel
209071-336A
Figure 3-4. UHF Command set
3-6
TM 55-1520-234-10
CONTROL
Mode
selector
FUNCTION
OFF - Turns off power.
PTT or T/R - Applies power.
RETRAN - Not applicable.
HOME - Connects set to
homing antenna and course
indicator for homing.
VOL control
Adjust audio level.
SQUELCH
control
DIS - Squelch disabled.
CARR -Squelch closed.
TONE -Squelch opens only
on signals containing 150 cps
tone modulation.
Whole
Megahertz
control
Decimal
Megahertz
control
Selects the whole megahertz
digits of the operating
frequency.
Selects the decimal megahertz
digits of the operating
frequency.
209071-337A
Figure 3-5. FM Command radio
3-7
TM 55-1520-234-10
INDICATOR
FUNCTION
OFF
vertical
Disappears when FM homing
circuits are functioning
properly. Remains in view
when FM homing circuits
are not functioning properly.
OFF
horizontal
flag
Disappears when homing
circuits are functioning
properly. Remains in view
when FM homing circuits
are not functioning properly.
Horizontal
pointer
Indicate strength of FM
homing signal being received.
Deflects downward as signal
strength increases.
Vertical
pointer
Indicates, when pointer is
centered that helicopter is flying
directly toward or away from
the station. Deflection of the
pointer indicates the direction
(right or left) to turn to fly
to the station.
Marker
beacon light
Not used.
209475-1B
Figure 3-6. Course indicator
c. Operating Procedures. Refer to FM Command
Radio for course indicator operating procedures.
3-7. Voice Security Equipment.
a. Description. The voice security equipment is
used with the FM Command Radio to provide secure
two-way communication. The equipment is controlled
by the control-indicator mounted in the pilot right
console.
b. Controls, Indicators, and Functions.
figure 3-7.
Refer to
c. Operating Procedures. Normal operation will
exist without its encoder/decoder and control indication
being installed in the helicopter.
However, two
operating modes are available when they are installed.
PLAIN mode for unciphered radio transmission or
reception and CIPHER mode for ciphered radio
transmission or reception.
Both modes may he
operated with or without retransmission units. Refer to
the following to operate the equipment in any particular
mode:
1. Preliminary Operating Procedure.
(a) Apply power to FM radio set.
(b) Set the control indicator POWER
switch to ON. The POWER switch must be in the ON
position, regardless of the mode of operation, whenever
the indicator is installed.
Change 7 3-8
TM 55-1520-234-10
CONTROL
1. POWER ON
Switch
(Two-Position
Circuit
Breaker)
FUNCTION
Connects power to the associated
TSEC/KY-28 cipher equipment
in the ON (forward) position,
and disconnects power from the
equipment in the OFF (aft)
position.
CONTROL
6. RE-X-REG
Switch
(Two-Position
Locking
Toggle)
FUNCTION
In the RE-X position. permits
ciphered communications
through a retransmission unit
(at a distant location). In the
REG position, permits normal
ciphered communications or
clear text.
NOTE
Switch must be in the ON
(forward) position for operation
in the PLAIN or CIPHER mode.
2. POWER ON
(Amber)
Indicator
(With Dimmer
Switch)
Lights when the associated
POWER ON switch is placed
in the ON (forward) position.
3. PLAIN
CIPHER
Switch
(Two-Position
Locking
Toggle)
In the PLAIN position, permits
normal (unciphered) communications on the associated FM
radio set. In the CIPHER
position, permits ciphered
communications on the
associated radio set.
4. PLAIN (Red)
Indicator
(with Dimmer
Switch)
Lights when the associated
PLAIN-CIPHER switch is in
the PLAIN position
5. CIPHER
(Green)
Indicator
(with Dimmer
Switch)
Lights when the associated
PLAIN-CIPHER switch is in
the CIPHER position.
7. ZEROIZE
Switch
(Two-Position
Locking
Toggle
Under
SpringLoaded
Cover)
8. Panel
Lights
CAUTION
Do not place the ZEROIZE switch
in the ON (forward) position
unless a crash or capture is
imminent. Normally in OFF
(aft) position. Placed in ON
(forward) position during
emergency situations to
neutralize and make inoperative
the associated TSEC/KY-28
cipher equipment.
Illuminate the control-indicator
(controlled by aircraft panel
lights).
206075-44B
Figure 3-7. Voice security equipment
3-9
TM 55-1520-234-10
the switch will be placed in RE-X
position.
(c) To transmit, press the press-to-talk
switch.
DO NOT TALK; in
approximately one-half second, a
beep will be heard. This indicates
the receiving station is now capable
of
receiving
your
message.
Transmission can now commence.
(c) When power is initially applied, an
automatic alarm procedure is
initiated.
1. A constant tone is heard in the
headset and after approximately
two seconds the constant tone
will change to an interrupted
tone.
2. To clear the interrupted tone,
depress and release the pushto-talk switch, the interrupted
tone will no longer be heard,
and the circuit will be in a
standby condition ready for
either transmission or reception.
NOTE
Only one voice security system can
transmit on a given frequency.
Always listen before attempting to
transmit to assure that no one else is
transmitting.
CAUTION
No traffic will be passed if the
interrupted tone is still heard after
depressing and releasing the pressto-talk switch.
(d) When transmission is completed,
release the press-to-talk switch.
This will return equipment to the
standby condition.
(e) To receive, it is necessary for
another station to send you a signal
first. Upon receipt of a signal, the
cipher equipment will be switched
automatically
to
the
receive
condition, which will be indicated by
a short beep heard in the headset.
Reception will then be possible.
Upon loss of the signal, the cipher
equipment will be automatically
returned to the standby condition.
(d) Set control unit function switch for
desired type of operation (2 and 3
below).
2. Plain Mode.
(a) Set the control indicator POWER
switch to ON.
(b) Set the PLAIN-CIPHER switch to
PLAIN (indicated by red light).
(c) Set the RE-X-REG switch to REG;
except
when
operating
with
retransmission units, at which time
switch will be placed in the RE-X
position.
(d) Press the press-to-talk switch and
speak into the microphone to
transmit. Release the press-to-talk
switch for reception.
3-8. VHF Radio Set.
a. Description. The set provides communication in
the very high-frequency (VHF) range of 116.000 through
149.975 MHz. This provides 1360 channels spaced 25
KHz apart. The control panel is installed on the gunner
floor immediately forward of his seat.
b. Controls and Function. Refer to figure 3-8.
3. Cipher Mode.
c. Operating Procedures.
1. OFF/PWR switch - PWR. Allow set to
warmup.
2. Frequency - Select.
3. RECEIVERS switch No. 3 - Forward
Position.
(a) Set the PLAIN-CIPHER switch to
CIPHER
switch
to
CIPHER
(indicated by a green light).
(b) Place the RE-X-REG switch to
REG, except when operating with
retransmission units, at which time
3-10
TM 55-1520-234-10
CONTROL
FUNCTION
OFF-PWR
switch
Turns power to the set
ON-OFF.
VOL control
Controls receiver audio volume.
COMM TEST switch
Turns squelch on or off.
Megahertz
control
Selects whole number part of
operating frequency.
Kilohertz
control
Selects the decimal number part
of operating frequency.
209073-17E
Figure 3-8. VHF Radio set
6. Microphone switch - Press to transmit.
7. OFF/PWR switch - OFF.
4. VOL - Adjust. If signal is not audible with
VOL control full clockwise press COMM
TEST switch to unsquelch circuits.
5. Transmit-interphone selector switch Position 3.
Section II. NAVIGATION
3-9. ADF Set.
a. Description. The direction finder set provides
radio aid to navigation. It operates in the frequency
range of 190 to 1750 KHz. When operating as an
automatic direction finder, the system, presents a
continuous indication of the bearing to the station by the
number 1 pointer of the radio magnetic indicator. It also
provides audio from the station. When operating the
loop mode, the system enables the operator to find the
bearing to the station by manually controlling the null.
direction of the directional antenna. The system also
operates as a radio receiver to receive voice and
unmodulated transmission in the ANT mode. The
control panel is marked ADF and is located in the pilot
right console.
c. Operating Procedures.
1. Receiver switch (NAV) - ON.
2. Mode selector switch - As desired. Allow
set to warmup.
3. FREQUENCY - Select.
(a) ADF OPERATION.
1. Mode selector switch - ADF.
2. BFO-OFF switch - OFF.
b. Controls, Indicators and Functions.
figure 3-9.
Refer to
3. TUNE meter - Tune
maximum deflection.
4. Volume - Adjust.
3-11
for
TM 55-1520-234-10
CONTROL OR
INDICATOR
CONTROL OR
INDICATOR
FUNCTION
1. GAIN
control
Controls receiver audio volume.
2. MODE
selector
switch
FUNCTION
3. LOOP L-R
switch
mode.
Rotates loop antenna to the
right or left when in LOOP
ADF - Automatic direction
finding showing station
direction.
4. BFO
switch
Turns beat frequency
oscillator on or off.
ANT - Low frequency radio
station receiver.
5. Tuning meter
the receiver.
Facilitates accurate tuning of
LOOP - Manual direction
finding or aural null operation.
6. Band
selector
switch
Selects desired frequency band.
7. Tune control
Selects the desired frequency.
OFF - Removes power from
set.
Figure 3-9. ADF Set
3-10. Gyromagnetic Compass Set.
(b) Antenna Operation.
1. Mode selector switch - ANT.
2. Volume - Adjust.
(c) Manual Loop Operation.
1.
2.
3.
4.
Mode selector switch - LOOP.
BFO-OFF switch - BFO.
Volume - Adjust.
Loop switch - Move left or right
for null.
4. Mode selector switch - OFF.
a. Description:
1. The gyromagnetic compass set is a
direction sensing system which provides a visual
indication of the magnetic heading (MAG) of the
helicopter. The information which the system supplies
may be used for navigation and to control flight path of
the helicopter. The system may also be used as a free
gyro (DG) in areas where the magnetic reference is
unreliable.
2. A radio magnetic indicator is installed in
the pilot instrument panel. A second radio magnetic
indicator (not shown) is installed in the gunner
instrument panel. The gunner indicator is a repeater
type instrument similar to the pilot
Change 9 3-12
TM 55-1520-234-10
indicator except that it has no control knobs. The
moving compass card on both indicators displays the
gyromagnetic compass heading. The number 1 pointer
on the indicators indicate the bearing to the station
selected on the ADF receiver.
b. Controls and Functions. Refer to figure 3-10.
c. Operating Procedures.
1. INV switch - MAIN or STBY.
2. Radio magnetic indicator (pilot only)
Check power failure indicator is not in
view.
(a) Slaved Gyro Mode
1. COMPASS switch - MAG.
2. Synchronizing knob - Center
(Null) annunciator.
3. Annunciator - Center position
and then does not change
(annunciator is de-energized in
the free gyro (DG) mode).
(c) Inflight Operation.
1. Set the COMPASS switch to
DG or MAG as desired for
magnetically slaved or free gyro
mode of operation. Free gyro
(DG) mode is recommended
when flying in latitudes higher
than 70°.
2. When operated in the slaved
(MAG) mode, the system will
remain synchronized during
normal flight maneuvers. During violent maneuvers the
system may become unsynchronized, as indicated by the
annunciator moving off center.
The system will slowly remove
all errors in synchronization;
however, if fast synchronization
is desired turn the synchronizing
knob in the direction indicated
by the annunciator until the
annunciator is centered again.
3. When operating in the free gyro
(DG) mode, periodically update
the heading to a known
reference by rotating the
synchronizing knob.
3. INV switch - OFF.
NOTE
The system does not have a
"fastslewing" feature. If the compass
is 180° off the correct helicopter
heading when the system is
energized it will take approximately
30 minutes for the compass to slave
to the correct headings.
3. Magnetic heading - Check.
(b) Free Gyro Mode.
1. COMPASS switch - DG.
2. Synchronizing knob - Set
heading.
3-13
TM 55-1520-234-10
CONTROL
FUNCTION
Pointer No. 1
Indicates bearing of ADF radio
signal.
Fixed Index
Provides reference mark for
rotating compass card.
Pointer No. 2
Not used.
Rotating compass
card
Synchronizing
knob
Is manually rotated to null
annunciator and synchronize
compass system.
Rotates under fixed index to
indicate helicopter magnetic
heading.
Annunciator
Shows dot (v) or cross (+) to
indicate misalignment (nonsynchronization of compass
system.
Power failure
indicator (OFF)
(flag)
Shows to indications loss of
power to compass system.
Compass Switch
(located on
pilots instrument
panel)
MAG position slaves gyro mode
DG position free gyro mode
SET HDG
Moves the heading select cursor
to desired heading.
Heading select
cursor
Indicates desired heading.
ADF/VOR knob
Selects ADF or VOR,
however, only ADF is used on
this installation. Leave knob
in ADF position.
CONTROL
FUNCTION
204475-2B
Figure 3-10. Gyromagnetic compass set
3-14
TM 55-1520-234-10
Section III. TRANSPONDER AND RADAR
3-11. Transponder Set AN/APX-72.
a. Description. The AN/APX-72 provides radar
identification capability.
Five independent coding
modes are available. Mode 1 provides 32 possible
codes which may be selected in flight. Mode 2 provides
4,096 possible codes, but must be preset before flight.
Mode 3/A provides 4,096 possible codes which may be
selected in flight. Mode C not used in this helicopter.
Mode 4 provides IFF capability when coupled with an
external computer, and must be preset prior to flight.
b. Controls and Functions. Refer to figure 3-11.
c. Operating Procedures.
1. MASTER control-STBY. Allow approximately 2 minutes for warmup.
2. Mode and code-Select as required.
3. Test as required.
4. MASTER control-LOW, NORM, EMER as
required.
5. IDENT-As required.
6. MASTER control-OFF.
d. Emergency Operation-Transponder set.
MASTER control-AMER.
e. MODE 4 Operation.
1. Before Exterior Check.
(a) MASTER switch-OFF.
(b) CODE switch-HOLD.
(c) CODE HOLD switch (on the pilot's
instrument panel)-HOLD.
If the
CODE HOLD switch is OFF and the
MASTER switch is in any position
other than-OFF, MODE 4 codes will
zeroize when the battery switch is
turned off during the BEFORE
EXTERIOR check.
2. Aircraft Runup Test.
Change 30 3-15
(a) MASTER switch-STBY for 2
minutes.
(b) CODE switch-A.
(c) MODE 4 TEST/ON/OUT switch-N.
(e) MODE
4
AUDIO/LIGHT/OUT
switch-AUDIO.
(f) MODE 4 ON/OUT switch-set the
switch to the ON position. Further
testing to check for correct coding
responses is done with ground test
equipment by moving the MASTER
switch to NORMAL.
When the
ground test equipment is moved
within 50 feet of the aircraft antenna
the following indications should be
observed if coding is correct.
(g) REPLY light should go on.
(h) AUDIO tone should be heard.
(i) If the above indications do not
occur, select the opposite code (A
or B) and repeat the check.
3. Zeroizing.
Mode 4 codes may be
zeroized by either of the following
methods:
(a) CODE switch-ZERO
(b) MASTER switch-FF. If the switch is
returned to NORMAL within 15
seconds, zeroizing may not occur.
(c) Aircraft electrical power-OFF. If the
CODE HOLD switch (on the pilot's
instrument panel) is at HOLD and
the CODE switch (on transponder)
has been moved to HOLD
momentarily prior to removing
electrical power, zeroizing will not
occur in steps (a) and (b) above.
TM 55-1520-234-10
4. Before Takeoff. CODE HOLD switch (on
the pilot's instrument panel) - OFF.
5. Engine Shutdown.
(1) If MODE 4 codes are to be held (not
zeroized):
a. CODE HOLD switch (on the
pilot's instrument panel) HOLD.
b. CODE switch (on transponder)
HOLD position momentarily and
release to position A or B (as
required).
c. MASTER switch - OFF.
(2) If MODE 4 codes are to zeroized,
use any of the zeroizing methods
above.
3-12. Radar Warning System AN/APR-39 (V-1).
a. Description.
The Radar Warning System
AN/APR-39 (V-1) provides the operator with both visual
and audible warning when a high radar threat
environment is encountered. The system is effectively
operated by use of a control, located on the pilot's
console, and an indicator, located on the instrument
panel. A self test is provided to ensure proper operation. The system can sort out, identify threat radar
signals, and display identified threats by means of
strobes displayed on the indicator. A flashing MA light
accompanied by a varying frequency audio tone heard
in the operator's headset gives indication of a missile
alert threat. The direction and proximity range of the
threat is displayed by a strobe line on the indicator. If
signal strength of threat is increased or threat is coming
closer, the strobe line on the indicator will increase in
length. A DSCRM switch is provided to enable the
operator to remove unwanted radar signals from the
indicator.
b. Controls and Functions. Refer to figure 3-12.
c. Operating Procedures.
1. PWR switch-ON.
2. SELF TEST - Depress.
3. DSCRM switch - ON or OFF.
4. AUDIO control - Adjust.
5. BRIL control - Adjust.
6. NIGHT-DAY control - Adjust.
7. PWR switch-OFF.
Change 30 3-16
TM 55-1520-234-10
6. MODE 4 Switch
ON
OUT
1. MASTER Control
OFF
STBY
2.
3.
4.
5.
Turns set off.
Places in warmup
(standby) condition.
LOW
Set operates at reduced
receiver sensitivity.
NORM
Set operates at normal
receiver sensitivity.
EMER
Transmits emergency
reply signals to MODE 1,
2, or 3/A interrogations
regardless of mode control
settings.
RAD TEST - MON Switch
RAD TEST
Enables set to reply to
TEST model interrogations.
Other functions of this
switch position are classified
MON
Enables the monitor test
circuits.
OUT
Disables the RAD TEST
and MON features.
IDENT-MIC Switch
IDENT
Initiates identification
reply for approximately
25 seconds.
OUT
Prevents triggering of
identification reply.
Spring loaded to OUT.
MIC
Not used.
MODE 3/A Code
Select Switches
Selects and indicates the
MODE 3/A four-digit
reply code number.
MODE 1 Code Select
Switches
Selects and indicates the
MODE 1 two-digit reply
code number.
Enables the set to reply to
MODE 4 interrogations.
Disables the reply to MODE
4 interrogations.
7. AUDIO-LIGHT Switch
AUDIO
Enables aural and REPLY
light monitoring of valid
MODE 4 interrogations and
replies.
LIGHT
Enables REPLY light only
monitoring of valid MODE 4
interrogations and replies.
OUT
Disables aural and REPLY
light monitoring of valid
MODE 4 interrogations
and replies.
8. CODE Control
Holds, zeroizes, or changes
MODE 4 Codes.
9. M-1 Switch
ON
Enables the set to reply to
MODE 1 interrogations.
OUT
Disables the reply to MODE
1 interrogations.
TEST
Provides test of MODE 1
interrogation by indication
on TEST light.
10. REPLY
Indicator
Lights when valid MODE 4
replies are present, or
when pressed.
11. M-2 Switch
ON
Enables the set to reply to
MODE 2 interrogations
OUT
Disables the reply to MODE
2 interrogations.
TEST
Provides test of MODE 2
interrogation by indication
on TEST light.
12. TEST
Indicator
Lights when the set responds
properly to a M-1, M-2,
M-3/A or M-C test, or
when pressed.
Note
Computer, transponder must be installed
before set will reply to a MODE 4
interrogation.
13. M-3/A Switch
ON
OUT
TEST
14. M-C Switch
helicopter.
Enables the set to reply to
MODE 3/A interrogations.
Disables the reply to
MODE 3/A interrogations.
Provides test of MODE 3/A
interrogation by indication
on TEST light.
Not applicable on this
209475-329G
Figure 3-11. Transponder set AN/APX-72
Change 25 3-17
TM 55-1520-234-10
CONTROL/INDICATOR
1.
2.
3.
4.
5.
MA indicator
BRIL control
NIGHT-DAY control
AUDIO control
DSCRM switch:
OFF
Without missile activity - Provides strobe lines for ground radar and normal
audio indications.
With missile activity - Provides strobe lines for ground radar, flashing
strobe line(s) for missile activity. and flashing MA (missile alert) light.
Without missile activity - No indications.
With missile activity - Flashing strobe lines for missile activity (no strobe
lines for ground radar), flashing MA light, and audio warning.
ON
6. SELF TEST switch:
with DSCRM switch OFF
PWR switch ON.
(NOTE: One minute warmup)
Monitor CRT and audio &
press and hold SELF TEST
Rotate indicator BRIL
control CW & CCW
Rotate control unit AUDIO
control between maximum
CCW and maximum CW
Release SELF TEST
Set DSCRM to ON.
Press & hold SELF TEST
7. PWR switch:
ON
OFF
FUNCTION
Flashing indicates high radar missile threat with DSCRM switch in ON.
Adjusts indicator illumination.
Adjust indicator intensity.
Adjusts radar warning audio volume.
Forward and aft strobes appear, extending to approximately the third circle on
the indicator graticule and 2.5 kHz PRF audio present immediately.
Within approximately 6 seconds. alarm audio present and MA lamp starts flashing.
Indicator strobes brighten (CW) and dim as control is rotated.
AUDIOS not audible at maximum CCW and clearly audible at maximum CW.
All indications cease.
Within approximately 4 seconds a FWD or AFT strobe and 1.2khz PRF audio present.
Within approximately 6 seconds the other strobe will appear and APRF
audio will double.
Applies power to radar set.
De-energizes radar set.
Figure 3-12. Radar Warning Indicator and Control AN/APR-39
Change 19 3-18
TM 55-1520-234-10
CHAPTER 4
MISSION EQUIPMENT
Section I. MISSION AVIONICS
4-1. Gun Camera.
Part of telescopic sight unit. Refer to Chapter 4, Section II.
Section II. ARMAMENT
WARNING: ARMAMENT FIRING
Firing of aircraft weapons in icing conditions is prohibited. The weapons covered are: TOW
missile, 2.75 inch FFAR, 40MM Grenade Launcher, 20MM Gun and 7.62MM MG.
A very serious safety hazard exists if aircraft weapons are fired in icing weather conditions.
The TOW missile warhead can detonate in close proximity to aircraft. The warhead fuse is
damaged as missile is launched through ice in missile launcher. Gun barrels and breeches can
rupture if gun muzzles are clogged with ice. The FFAR are held captive in the launcher tubes by
the frozen ice.
Helicopter control shall be maintained, especially at low altitude, to prevent hazardous flight
conditions and loss of TOW missile control. When the gunner is tracking TOW missile and the
pilot using his helmet sight to fire the turret simultaneously, the pilot may have a strong
tendency to lose contact with his instrument panel and outside references or develop target
fixation.
When firing weapons while using night vision goggles, rocket and TOW exhaust, muzzle
flashes, and flares could cause light blindness. Extreme caution should be exercised at all times
while in the night vision environment.
4-2. Armament Configuration.
a. Authorized Armament Configurations. Figure 41
shows
the
authorized
armament
loading
configurations.
b. Interrelation of Armament.
The armament
subsystems are interfaced with one another. Figure 4-2
shows the pilot and gunner control components in
relationship to each armament subsystem.
c. Armament Firing Modes. Figure 4-3 shows the
switch positions for principle firing modes.
flexible mode by the pilot, flexible mode by the gunner.
The turret can travel 107.5 degrees left or right in
azimuth and 12 to 17.5 degrees up and 50 degrees
down in elevation.
(a) Machine Gun.
The gun is an
electrical driven, automatic, air-cooled, six barrel, and
six bolts weapon. The gun is capable of firing sixsecond bursts at 2000 or 4000 rounds per minute. The
ammunition drum stores a maximum of 4000 rounds of
linked ammunition in a folding fan arrangement. The
drum is driven by the machine gun drive motor through
the flexible shaft.
NOTE
Operation of MILES/AGES; refer to
TM 9-1270-223-10.
4-3. Description.
a. System Description.
(1) Turret. The M28A1E1 turret (figure 4-4)
(TM 9-1090-203-12 and TM 9-1090-203-12-1) contains a
7.62 MM machine gun and a 40 MM grenade launcher.
The ammunition drums (figure 4-5) are located in the
ammunition bay.
The turret is hydraulically and
electrically operated. It can be fired in the fixed or
Change 30 4-1
WARNING
To allow safe firing of M129 Grenade
Launcher in TSU/GUN mode, do not
fire at altitudes below 125 feet AGL.
Place turret depression limit switch
in ON position.
Turret control
reverts to Helmet Sight System
whenever TOW Missile System is
shutdown due to malfunctions on
helicopters without MWO 55-1500220-30-2 incorporated.
TM 55-1520-234-10
Figure 4-1. Authorized armament configurations (Sheet 1 of 2)
4-2
TM 55-1520-234-10
Figure 4-1. Authorized armament configuration (Sheet 2 of 2)
Change 9 4-2A
TM 55-1520-234-10
(b) Grenade Launcher. The launcher is
an electrically driven, rapid-firing, air-cooled weapon.
The launcher is capable of firing 10second burst at 400
grenades per minute. The launcher is cam operated by
the gun drive through the flexible shaft.
The
ammunition drum stores a maximum of 265 linked antipersonnel fragmentation grenades.
The drum is
electrically driven by a motor mounted on the drum.
(2) TOW Missile. The TOW (tube-launched,
optically-tracked, wire guided) missile subsystem (TM 91425-473-20) is a heavy anti-tank/assault weapon. The
subsystem utilizes optical and IR (infra-red) means to
track a target and guide the missile. Isolation from
helicopter motions and vibrations is provided, thus
enabling a high first hit probability. The subsystem
physical characteristics does not degrade the stability
and operational characteristics of the helicopter. One or
two TML (TOW Missile Launcher) (figure 4-6) support
two missiles each on the outboard ejector racks.
NOTE
The subsystem is designed to be
effective during daylight conditions.
Use at night may be effective if flares
are used to augment visibility.
Problems with glare on sight reticles,
inability to adjust reticle in intensity
during target tracking, and difficulty
in acquiring targets at unknown
locations during darkness, will
degrade system performance during
night operations.
CAUTION
Use of night vision goggles with the
TOW sight unit is not recommended
since it does not increase visibility
and creates a risk of scratching the
sight lens.
(3) Rockets. The 2.75 inch folding fin aerial
rocket (FFAR) (TM 9-1055-460-14) subsystem is a light
anti-personnel/assault weapon. A launcher
Change 14 4-2B
TM 55-1520-234-10
Figure 4-2. Control components in relationship to armament subsystem.
Change 9 4-3
TM 55-1520-234-10
Figure 4-3. Armament firing modes (Sheet 1 of 7)
Change 15 4-4
TM 55-1520-234-10
Figure 4-3. Armament firing modes (Sheet 2 of 7)
4-5
TM 55-1520-234-10
Figure 4-3. Armament firing modes (Sheet 3 of 7)
4-6
TM 55-1520-234-10
Figure 4-3. Armament firing modes (Sheet 4 of 7)
4-7
TM 55-1520-234-10
Figure 4-3. Armament firing modes (Sheet 5 of 7)
4-8
TM 55-1520-234-10
Figure 4-3. Armament firing modes (Sheet 6 of 7)
4-9
TM 55-1520-234-10
Figure 4-3. Armament firing modes (Sheet 7 of 7)
4-10
TM 55-1520-234-10
Figure 4-4. Turret
Change 9
4-11
TM 55-1520-234-10
Figure 4-5. Ammunition drums
Change 9
4-12
TM 55-1520-234-10
Figure 4-6. TOW Missile launcher
4-13
TM 55-1520-234-10
(figure 4-7), can he mounted on each of the inboard and
output ejector races.
(4) Wing Gun Pod. The pod (figure 4-8) is a selfcontinued unit housing a M134 high rate 7.62 mm
machinegun, its own electrical system, battery charging
system, and a maximum of 1500 rounds of ammunition.
The M18 gun pod is capable of firing 4,000 shots per
minute. The M18A1 gun pod has a dual firing rate of
2,000, or 4,000 shots per minute depending on the
position of the firing rate switch located at the rear of the
pod.
(5) Smoke Grenade Dispenser. A dispenser (figure
4-9) (TM 9-1330-208-25) may be attached to each
outboard ejector rack or strapped to the rocket launcher
on the outboard rack. Each dispenser contains two
independently operated racks of six white or color
smoke grenades, 12 per dispenser.
One to four
grenades may drop at one time by the two dispensers.
(6) Wing Stores Jettison. Each of the four ejector
racks are equipped with an electrically operated ballistic
device to jettison the attached weapon during an
emergency. Each device has two cartridges. The
second cartridge fires automatic if the first fails to fire.
Pressing the switch will drop one to four grenades and
cause a 400-cycle audio tone in the pilot headset. The
tone will continue as long as switch is pressed. When
the last grenade from the rack is dropped, the tone will
continue until the LH/RH ARM switch (figure 4-13) is
placed in the OFF position.
(5) Pilot Wing Stores Jettison Switch. The
guarded switch is on the pilot instrument panel.
Activation of the switch will jettison the weapons from
the inboard, outboard, or all four of the wing ejector
racks. In some situations, jettison will not occur. Refer
to figure 4-12 for various jettison and non-jettison
combinations.
(6) Pilot Armament Circuit Breakers. Refer to
figure 4-14.
(7) Pilot Steering Indicator (PSI).
figure 4-15.
Refer to
(8) Pilot Missile Status Panel (MSP). Refer to
figure 4-16.
(9) Pilot Gunner Accuracy Control Panel
(GACP). Refer to figure 4-17.
(7) Helmet .Sight Subsystem (HSS). The HSS
(figure 4-10) (TM 9-1270-212-14) permits the pilot or
gunner to rapidly acquire visible targets and to direct the
turret and/or the telescopic sight unit (TSU) to those
targets.
(10) Pilot Reflex Sight. Refer to figure 4-18.
(11) Pilot Helmet Sight. Refer to figure 4-10.
(12) Pilot Cyclic Armament Switches. Refer to
figure 2-4.
b. Pilot Switches aid Indicators.
NOTE
Pilot panels and switches are
interfaced with other pilot/gunner
panels and switches for weapon
operations and wing stores jettison.
Figure 4-2 shows panel interface.
Figure 4-3 shows switch interface.
c. Gunner Switches and Indicators
NOTE
Gunner panels and switches are
interfaced with other gunner/pilot
panels and switches for weapon
operations and wing stores jettison.
Figure 4-2 shows panel interface.
Figure 4-3 shows switch interface.
(1) Pilot Armament Control/ Panel. Refer to
figure 4-11.
(2) Pilot Wing Stores Control Panel. Refer to
figure 4-12.
(3) Pilot Smoke Grenade Dispenser Control
Panel. Refer to figure 4-13.
(1) Gunner Cyclic Armament Switches. Refer
to figure 2-5.
(2) Gunner Helmet Sight. Refer to figure 410.
(3) Gunner Telescopic Sight Unit (TSU).
Refer to figure 4-19.
(4) Pilot Smoke Grenade Release Switch.
The switch is on the pilot collective stick switchbox.
Change 7
4-14
TM 55-1520-234-10
Figure 4-7. Folding fin aerial rocket (2.75 inch) launcher
Change 9
4-1 5
TM 55-1520-234-10
Figure 4-8. Wing gun pod
Figure 4-9. Smoke grenade dispenser
Change 7
4-16
TM 55-1520-234-10
Figure 4-10. Helmet sight subsystem (HSS)
Change 9
4-17/(4-18 blank)
TM 55-1520-234-10
Figure 4-11. Pilot armament control panel
Change 9
4-19
TM 55-1520-234-10
Figure 4-12. Pilot wing stores control panel
Change 30
4-20
TM 55-1520-234-10
Figure 4-13. Pilot smoke grenade dispenser control panel
4-21
TM 55-1520-234-10
Figure 4-14. Pilot armament circuit breakers
Change 9
4-22
TM 55-1520-234-10
Figure 4-15. Pilot steering indicator (PSI)
Change 9
4-23
TM 55-1520-234-10
Figure 4-16. Pilot missile status panel (MSP)
NOTE
(a) The camera will operate at speeds of 16,
22, 32, and 64 frames per second. The selection of
camera speed is made manually before takeoff by
setting the speed control knob on the lower right side of
the camera.
The light shield on the telescopic
sight unit headrest is not compatible
with standard eyeglasses.
(4) Gunner Armament Control Panel. Refer
to figure 4-20.
(5) Gunner Wing Stores Jettison Switch. The
guarded switch is on the gunner instrument panel.
Activation of the switch will jettison all weapons from all
ejector racks. The switch is powered and protected by
the emergency jettison circuit breaker in the electrical
compartment.
(6) Gunner Sight Hand Control (SHC). Refer
to figure 4-21.
(b) Proper functioning of the camera
exposure control switch on the TOW control panel
(figure 4-22) requires presetting of the diaphragm
control ring to the proper F-stop marking on the lens
barrel as follows:
Frame SpeedLens Setting (Day)Lens Setting (Night) -
32
f/4
f/2.8
4-4. Preflight Procedures.
WARNING
(7) Gunner TOW Control Panel (TCP). Refer
to figure 4-22.
The machine gun in the turret and
wing gun pods will fire when rotated
by hand or otherwise. The grenade
launcher in the turret will fire when
the barrel is pushed in.
(8) Gunner Camera.
The motion picture
camera (Figure 4-19) is designed for use with standard
16mm black and white or color film. An expendable,
subdued-light loading, 50-foot film cartridge is supplied.
Change 30
16
f/5.6
f/2.8
4-24
64
f/2.8
f/2.8
TM 55-1520-234-10
Figure 4-17. Pilot gunner accuracy control panel (GACP)
4-25
TM 55-1520-234-10
Figure 4-18. Pilot reflex sight
4-26
TM 55-1520-234-10
Figure 4-19. Gunner telescopic sight unit (TSU)
Change 19
4-27
TM 55-1520-234-10
Figure 4-20. Gunner armament control panel (Sheet 1 of 2)
Change 30
4-28
TM 55-1520-234-10
Figure 4-20. Gunner armament control panel (Sheet 2 of 2)
Change 20
4-28A/(4-28B blank)
TM 55-1520-234-10
Figure 4-21. Gunner sight hand control (SHC)
Change 19
4-29
TM 55-1520-234-10
Figure 4-22. Gunner TOW control panel (TCP)
Change 19
4-30
TM 55-1520-234-10
NOTE
9. Gate solenoid - Plunger returns to extended
position when pressed, electrical connectors
condition and security.
Checks herein are only applicable if
the armament is installed. Checks
herein are in addition to those listed
in Chapter 8. Chapter 4 does not
duplicate Chapter 8 except for safety
checks.
10. Gun drive - Flexible shaft and electrical
connectors condition and security.
11. Gun timing pin - Set.
4-5. BEFORE EXTERIOR CHECK - ALL ARMAMENT
- PREFLIGHT.
1. Wing ejector racks - Jettison safety pins
installed.
12. Delinking feeder timing - Set.
13. Hydraulic lines - Condition and security.
14. Access door-Close/replace and secure.
2. TOW launcher - Missile engaging handle up.
3. Rocket launcher - Igniter arms in contact with
rockets.
15. Telescopic sight unit - Rotate TSU 90 degrees.
Check covers removed and windows clean.
4. MASTER ARM switch - OFF.
b. Ammunition Bay Right Side - Machine Gun.
5. PLT OVRD switch -OFF.
1. Bay door - Open.
4-6. EXTERIOR CHECK -TURRET - PREFLIGHT.
2. Ammunition drum - Condition and secure with
quick-release pins.
a. Turret Right Side - Machine Gun.
3. Flexible shaft-Condition and secure to torque
limiter.
1. Bullet trap - Installed.
4. Round counter - Condition and electrical cable
connected.
2. Access door - Open/remove.
3. Barrel clamp and retaining bolt - Secure.
4. Gun Mounting - Quick-release pins (ring up)
installed through gun saddle outboard holes and
recoil adapters, recoil adapters secure on gun,
gun support extension over saddle azimuth
boresight support.
5. Ammunition chute - Condition, security, and
ammunication present.
6. Turret circuit breakers - In.
7. Hydraulic/electrical lines-Condition and security.
5. Link ejection chute - Condition and security.
8. Bay door - Close and secure.
6. Ammunition chute - Condition and security.
c. Turret Left Side - Grenade Launcher.
7. Cartridge
security.
ejection
chute
-
Condition
and
1. Access door - Open/remove.
2. Gun cradle mounting - Quick-release pins (ring
up) installed through gun saddle inboard holes
and recoil adapters, recoil adapters secure on
cradle, cradle rear bushing over saddle azimuth
boresight support.
8. Delinking feeder - Condition and security.
Change 7
4-31
TM 55-1520-234-10
3. Launcher mounting - Launcher front support
rollers in gun cradle fords, launcher rear secure
to cradle with bolts.
2. Electrical connector - Upper launcher harness
connected to helicopter receptacle and jettison
quick disconnect lanyard attached to harness
and launcher. Quick disconnect lanyard not
twisted. Lower launcher harness connected to
upper launcher harness receptacle.
4. Ammunition chute/feed tray Condition, security,
and ammunition present.
5. Ejection chute -Condition and security.
3. Missile Installation - Missile front ring seated in
forward tube mating ring, hinged center gate
and debris director secure with captive locking
pins. Note number of and position of installed
missiles (needed for interior check).
6. Gun drive - Flexible shaft and electrical
connectors condition and security.
7. Hydraulic lines - Condition and security.
4-8.
EXTERIOR CHECK-ROCKETLAUNCHER
PREFLIGHT.
8. Access door - Close/replace and secure.
1. Launcher Mounting - Launcher aft and forward
bomb suspension lugs secure to helicopter
ejector racks. Rack swaybrace bolts firmly
against launcher but not denting exterior.
d. Ammunition Bay Left Side - Grenade Launcher.
1. Bay door-Open.
2. Ammunition drum - Condition and secure with
quick-release pins.
2. Electrical connection - Harness connected to
launcher and helicopter receptacles. Jettison
quick disconnect lanyard attached to harness
and launcher.
3. Drive motor - Condition, security, and electrical
cable connected.
3. Launcher - Launcher exterior and tube interiors
for damage and corrosion.
4. Round counter - Condition and electrical cable
connected.
4. Rocket installation - Rocket aft end secure in
launcher tube aft detent.
5. Ammunition chute - Condition, security, and
ammunition present.
6. Hydraulic/electrical
security.
lines
-
Condition
-
5. Igniter arms - Damage and corrosion.
and
4-9.
EXTERIOR CHECK
PREFLIGHT.
-
WING
GUN
POD
7. Bay door - Close and secure.
1. Front fairing - Removed.
e. Machine gun bullet trap - Remove.
2. Bullet trap - Installed.
4-7. EXTERIOR CHECK-TOW-PREFLIGHT.
1. Launcher Mounting - Upper launcher aft and
forward adjustable bomb lugs secure to
helicopter ejector racks and rack swaybrace
bolts firmly against launcher swaybrace pads.
Lower launcher aft and forward attaching points
secure to upper launcher aft and forward
attaching points.
Change 9
3. Pod mounting - Pod front and rear lugs secure
to helicopter ejector racks. Rack swaybrace
bolts firmly against pod but not denting exterior.
4. Electrical connection - Harness connected to
pod and helicopter receptacles. Jettison quick
disconnect lanyard attached to harness and pod.
4-32
TM 55-1520-234-10
5. Pod - Pod exterior for condition (includes front
fairing removed during Before Exterior Check).
6. Gun barrel clamp and retaining bolt Secure.
7. Gun mounting - Recoil adapters, quick release
pins, and rear mount secure.
8. Gun gate solenoid - Plunger returns to extended
position when pressed, electrical connectors
condition and security.
9. Gun exit unit - Condition and security.
10. Gun feeder wheel - Condition and security.
11. Gun electrical drive - Drive and electrical
connectors condition and security.
4-10.
EXTERIOR CHECK-SMOKE
DISPENSER - PREFLIGHT.
GRENADE
1. Dispenser Mounting - On ejector rack, dispenser
front and rear mounting lugs secure to
helicopter ejector rack and rack swaybrace bolts
firmly against dispenser but not denting exterior.
On rocket launcher, dispenser straps are secure
around launcher.
2. Electrical connection - Dispenser harness
connected to helicopter receptacle. Jettison
quick disconnect lanyard attached to harness
and dispenser.
3. Grenades - Desired colors installed and safety
pins removed.
4. Dispenser - Condition, ejector safety pins
removed, and dispenser cocked.
12. Gun safing sector - Secure.
4-11. BEFORE STARTING ENGINE CHECK.
13. Gun round counters (2) - Set.
NOTE
Check to be performed prior to
starting engine. Chapter 8 preflight
before starting engine check.
14. Gun timing pin - Set.
15. Gun feeding timing pin - Set.
1. Pilot smoke grenade dispenser panel Color
indicating dials set to indicate color of grenades
installed noted during exterior check.
16. Gun exit unit timing pin - Set.
17. Rear fairing - Remove.
2. Pilot PSI - Elevation/azimuth sight line position
bars centered on reference ring, coarse scale
azimuth pointer centered, ATTK/RDY/FIRE
annunciators and ascent/descent pointers not
displayed.
18. Battery switch - CHARGE.
19. Heater switch - As desired.
20. High/low rate firing switch - As desired (if
equipped).
3. Gunner SHC ACQ/TRK/STOW switch - STOW.
21. Aircraft field switch - As desired (if equipped).
4. Gunner TCP MODE SELECT switch OFF,
system status annunicator displays OFF.
22. Battery - Damage, leaking cells, and corrosion.
23. Rear fairing - Replace and secure.
5. Gunner TCP CAMERA switch - OFF.
6. Gunner TCP EXPOSURE switch - BRT.
24. Bullet trap - Remove.
7. Gunner TCP TSU RTCL switch -OFF.
25. Front fairing - Replace and secure.
Change 9
4-33
TM 55-1520-234-10
assemblies are properly attached to BIT
magnets, check all cable connections, cycle
MASTER ARM switch from STBY to OFF and
back to STBY, and actuate BIT switch again.
8. Gunner TCP MISSILE SELECT switch-1.
9. Gunner AMMO RSV PERCENT dials-Set.
10. Pilot and gunner helmets-ON.
b. HSS TO TURRET CHECK.
4-12. BEFORE TAKEOFF CHECK-ALL ARMAMENTPREFUGHT.
WARNING
The following checks shall not be
performed
with
Tow
Missiles
installed.
1. TCP mode select switch to TSU/GUNS.
2. Pilot and gunner HS arm assemblies-Attach to
helmet.
3. Pilot and gunner HS eyepieces-Extended over
eye.
NOTE
Check cannot be performed prior to
engine start because hydraulic
power is required for portions of the
check.
4. Gunner reticle-Adjust, focus, and test lights.
HSS RETICLE OFF BRT control to be in full
BRT.
After adjust and focus, move HSS
RETICLE TEST switch to TEST. If reticle goes
out, one or more lights may have failed.
a. HSS BUILT-IN-TEST CHECK.
5. Gunner HS to turret check-TSU left hand grip
ACTION switch depressed, gunner moves head,
turret follows head movement, reticle flashes
until gun line is coincident with HSS line.
Release ACTION switch.
NOTE
Any failure of HSS RETICLE or
malfunction of HSS SYSTEM should
be referred to armament personnel
for maintenance operation check.
This check will be completed using
the identifying pilot's and/ or
copilot's HSS SIGHT.
WARNING
In the following check, do not press
the gunner cyclic TRIGGER TURRET
FIRE switch.
1. Pilot and gunner HS arm assemblies-Attached
to BIT Magnets.
6. Gunner emergency mode check-Gunner PLT
OVRD switch in OVRD and cyclic TRIGGER
ACTION switch depressed, repeat step 4 above,
then PLT OVRD switch to OFF.
7. Pilot WPN CONT switch-PLT. Pilot reticleAdjust, focus, and test lights. HS RTCL OFF
BRT control to be in full BRT. After adjust and
focus, move HS RTCL TEST switch to TEST. If
reticle goes out, one or more lights may have
failed.
2. Pilot MASTER ARM switch-STBY.
3. Pilot WPN CONT switch-GUNNER.
4. Pilot TURRET switch-BOTH.
5. Indicator light test-Press pilot and gunner
ARMED/ STBY, 7.62/7.62/40/40, and gunner
PLT/GNR/ IN'FC/GO panels.
All sections
illuminate.
6. Gunner HSS BIT switch-BIT. Test passed if GO
light illuminates, failed if PLT/G NR C lights
illuminate.
If failed, ensure HSS arm
Change 30
8. Pilot HS to turret check-Cyclic TRIGGER
ACTION switch depressed, pilot moves head,
turret follows head movement. Pilot makes
rapid rotational head movement, reticle flashes
until gun line is coincident with HS line.
Release TRIGGER ACTION switch.
4-34
TM 55-1520-234-10
c. HSS TO TSU CHECK
1. Pilot and gunner HS eyepieces-Extended over
eye.
4. SHC Stick-Move full left and right. Gunner
should observe the ON and OFF gun flag. This
shows turret is out of coincidence with TSU.
5. LHG ACTION BAR-Release.
2. Gunner HS reticle-On a target.
6. ATS SWITCH-STOW.
3. SHC ACQ/TR/STOW switch-ACQ.
4. SHC
ACQ/TRK/STOW
switch-Released.
Returns TRK. Gunner HS eyepiece retracts.
e. TOW BUILT-IN-TEST CHECK.
1. Pilot WPN CONT switch-UNNER.
5. TSU reticle-Displayed target.
6. Gunner HS eyepiece-Extended over eye.
7. Pilot HS reticle-n another target.
2. Gunner TCP MODE SELECT switch-TBY TOW,
system status annunciator OFF, after 10
seconds. TEST, before two minutes PWR ON,
TSUISCA/ EPS/MCA fail indicators display
black flags. Black flag indicates automatic BIT
passed, white flag indicates failure.
8. SHC PHS ACQ switch-Press.
9. SHC PHS ACQ switch-Released. Gunner HS
eye- piece retracts.
10. TSU reticle-Displays pilot target.
3. Gunner TCP BIT switch-Hold, gunner TSU
reticle ATTK/RDY/GUNS indicators, pilot PSI
ATTK/
RDY/FIRE
annunciators,
and
ascend/descent pointers displayed. Release
switch.
11. ACQ/TRK/STOW-STOW.
12. LHG MAG switch-LO.
13. TCP-TSU/Guns.
d. TSU to Turret Check.
1. LHG MAG Switch-LO.
2. ATS Switch-TRK.
3. LHG action bar-Depressed.
Change 30
4-34.1/(4-34.2 blank)
4. Gunner TCP and pilot MSP missile status
indicators-Displays missile load configuration
noted during exterior check.
5. BIT override check-TCP MODE SELECT switch
OFF, then STBY TOW, when TCP annunciator
displays TEST, move ACQ/TRK/STOW switch
from STOW to TRK, annunciator diplays PWR
ON.
6. TOW BIT (Performed above) information.
Automatic or manual BIT may be performed
before, during, or after operations.
TM 55-1520-234-10
2. LHG MAG switch-LO. Switch must be positively
held in position before releasing. TSU eyepiece
displays low magnification (two power) of target.
3. SHC track control stick-Move full left and down.
TSU rapidly moves left and down. ACQ/TRK/
STOW switch to TRK.
4. SHC track control stick-Release. TSU view not
rotating. Pilot PSI azimuth sightline position bar
and course scale azimuth pointer full left,
elevation sightline position bar full down.
g. TSU SLOW RATE TRACKING CHECK.
(a) TOW BIT Initiation.
1. Gunner SHC ACQO/RKISTOW switch
STOW.
2. Automatic BIT-Gunner TCP MODE
SELECT switch from OFF to STBY TOW.
3. Manual BIT (STBY TOW only)-When
gunner TCP system status annunciator
displays PWR ON, press and release TCP
BIT switch.
(b) TOW BIT Termination.
1. Automatic or Manual Bit-Automatically
completed within two minutes.
2. Termination During BIT. Gunner SHC
ACQ/ TRKISTOW switch set to ACQ or
TRK or TCP MODE SELECT switch set to
MAN ARMED, AUTO ARMED, or OFF.
1. Gunner-Look into TSU eyepiece during check.
Mode select switch STBY TOW.
2. LHG MAG switch-HI. Switch must be positively
held in position before releasing. TSU eyepiece
displays high magnification (13 power) of target.
3. SHC track control stick-Move full right and up.
TSU slowly moves right and up.
4. SHC track control stick-Release. TSU view not
rotating. Pilot azimuth sightline position bar and
course scale azimuth pointer full right, elevation
sightline position bar full up.
h. TOW MOTION COMPENSATION CHECK.
1. Gunner-Look into TSU eyepiece during check.
2. LHG ACTION switch-Press.
3. SHC track control stick-Move left and down.
Release when TSU starts moving, TSU continue
to move.
f. TSU FAST RATE TRACKING CHECK.
1. Gunner-Look into TSU eyepiece during check.
Mode select switch STBY TOW.
Change 30
4. LHG Action switch-Release. TSU stops..
4-35
TM 55-1520-234-10
6. Gunner COMP switch - ON.
i. Before Takeoff Check-All Armament.
1. Gunner PLT ORIDE switch-FF.
7. Gunner TURRET DEPR LIMIT switch-OFF.
2. PILOT MASTER ARM switch-STBY.
8. Gunner TCP MODE SELECT switch-TSU/GUN.
3. TCP-TSU/GUN.
9. Gunner LHG ACTION switch-Depressed.
4. TOW launchers-Missile arming lever down.
10. Gunner HS/TSU reticle-ON target.
5. Wing ejector rack jettison safety pins-Removed.
11. Gunner LHG TRIGGER switch-Depressed.
Machine gun-First detent 2000 rounds per
minute, second detent 4000. Grenade launcherFirst or second detent 400 grenades per minute.
4-13. INFLIGHT PROCEDURES - ALL ARMAMENT
The following armament inflight procedure
paragraphs are based on only one weapon installed, all
armament circuit breakers in, and armament preflight
interior check performed. Refer to figure 4-3 for firing
modes when two or more weapons are installed.
12. Emergency procedures-Refer to Chapter 9,
Section II.
b. Pilot Operation - Turret.
1. Pilot MASTER ARM switch-ARM.
4-14. TURRET OPERATIONG - INFLIGHT
PROCEDURES.
2. Pilot WPN CONT switch-PLT when using
helmet sight (HS), FIXED when using reflex
sight.
a. Gunner Operation - Turret.
1. Pilot MASTER ARM switch-ARM.
3. Pilot TURRET switch-As desired.
2. Pilot WPN CONT switch-GUNNER.
4. Gunner PLT OVRD switch-OFF.
3. Pilot TURRET switch-As desired.
5. Gunner RANGE switch-As desired.
4. Gunner PLT OVRD switch-OFF.
6. Gunner COMP switch-ON.
5. Gunner RANGE switch-As desired.
7. Gunner TURRET DEPR LIMIT switch-OFF.
Change 30
4-36
8. Pilot reflex sight - Set when using reflex sight
9. Pilot cyclic TRIGGER ACTION
depressed when using HS.
switch -
TM 55-1520-234-10
14. Gunner TSU LHG ACTION switch Depressed.
Gunner TSU reticle ATTK indicator comes on,
pilot PSI ATTIK annunciator appears. LHG
action switch depressed provide motion
compensation during tracking.
10. Pilot MS/reflex sight reticle - On target
11. Pilot cyclic TRIGGER TURRET FRE switch
Depressed. Machine gun - First detent 2000
rounds per minute, second detent 4000.
Grenade launcher - First or second detent 400
grenades per minute.
12. Emergency procedures - Refer to Chapter 9,
Section III.
15. Helicopter position - Maneuvered to align pilot
PSI sightline position bars within prelaunch
constraint boundary and maintained a roll
attitude of less than ± 5°. Gunner TSU reticle
RDY indicator comes on, pilot PSI RDY
annunciator appears.
16. Pilot PSI sightline position bars - Crosses PSI
reference ring, pilot begins countdown for
gunner. "Standby ......... ready."
415. TOW Operation - Inflight Procedures.
NOTE
Gunner cannot fire if the helicopter is
not within the prelaunch constraint
boundary. Gunner can override the prelaunch
constraint
boundary
limitation by pressing the CONST
OVRD switch on the SHC. If this
mode of operation is employed,
degraded system performance can
be expected.
1. Pilot MASTER ARM switch - ARM.
2. Pilot WPN CONT switch - GUNNER.
3. Gunner TCP MODE SELECT switch ARMED
MAN for manual missile selection, ARMED
AUTO for automatic missile selection.
4. Gunner TSU LHG MAG switch -LO. Switch
must be positively held in position before
releasing.
NOTE
Smoke may emerge from launcher
after TRIGGER is depressed and before missile exits launcher. The
smoke is caused by the missile gyro
and battery squibs firing and should
not be regarded as a misfire. A
misfire has occurred if missile fails
to exit launcher within 1.5 seconds
(pilot
PSI
RDY
annunciator
disappears).
5. Gunner TSU reticle - Focus.
6. Gunner TCP CAMERA/EXPOSURE switches As required.
7. Gunner TCP MISSILE SELECT switch - Set to
first loaded missile, pilot informed of missile
selected, pilot MSP displays SEL for missile
position indicator.
8. Gunner SHC ACQ/TRK/STOW switch - ACQ.
9. Gunner HS reticle - On target.
10. Gunner SHC ACQ[IRK/STOW switch -TRK.
11. Gunner TSU reticle - On target.
17. Gunner TSU LHG TRIGGER switch Depressed
when helicopter is within range of target. Pilot
PSI FIRE annunciator appear.
After 1.5
seconds, pilot PSI ATTK and RDY annunciators
disappear, gunner TSU reticle ATTK and RDY
indicators go out.
WARNING
Do not turn helicopter to the side
from which a missile is file. The
helicopter may strike the command
wire.
12. Gunner TSU LHG MAG switch - HR. Switch
must be positively held in position before
releasing.
13. Gunner SHC track control stick - Move as
required to keep TSU crosshairs on target.
18. Helicopter position - Maneuvered to keep pilot
PSI sightline position bars within postlaunch
constraint boundary until wire cut or missile
impact
Change 31
4-37
TM 55-1520-234-10
CAUTION
Loss of missile guidance could
result
if
a
drastic
maneuver
(exceeding postlaunch constraint
boundary) is made.
3. Pilot RKT PR SEL switch - As desired
4. Pilot WG ST ARM switch - As required.
ARMED indicator comes on.
19. Gunner TSU reticle crosshairs - On target until
wire cut or missile impact Gunner SHC track
control stick used to keep crosshairs on target
20. Additional missile firing - The next missile is
selected automatically if the gunner TCP MODE
SELECT switch is on ARMED AUTO, manually
selected if switch is on ARMED MAN by the
MISSILE SELECT switch.
a. Pilot MSP - Displays SEL for missile
selected.
5. Pilot reflex sight - Adjust and align with target.
6. Pilot cyclic WING ARM FIRE switch Depressed.
4-17. Wing Gun Pod Operation - Inflight
Procedures.
1. Pilot MASTER ARM switch - ARM.
2. Gunner PLT OVRD switch - OFF.
WARNING
If rockets are being fired, the pilot
cyclic WING ARM FIRE switch must
be released prior to moving WG ST
ARM switch from OUTBD to INBD.
WING gun pod rounds may detonate
inflight rockets in proximity of
helicopter.
b. Gunner TSU LHG MAG switch - LO.
Switch must be positively held in position
before releasing.
c. Fire missile - Repeat paragraphs 4-15.9
through 415.19.
21. Emergency procedures - Refer to Chapter 9,
Section II.
4-16. Rocket Operation - Inflight Procedures.
3. Pilot WG ST ARM switch - INBD.
indicator comes on.
ARMED
4. Pilot reflex sight - Adjust and align with target.
CAUTION
Firing multiple Mark 66 rockets in
excess of 8 pair, less than 20 feet
skid height with the engine inlet
shield installed may result in surge
damage to the drive system and
engine. The probability of an engine
surge decreases as the number of
rockets fired in a salvo decreases
and/or the helicopter altitude above
the ground increases.
5. Pilot cyclic WING ARM FIRE switch Depressed.
4-18. Smoke Grenade Dispenser Operation - Inflight
Procedures.
1. Pilot MASTER ARM switch - STBY or ARM.
2. Gunner PLT OVRD switch - OFF.
3. Pilot LH ARM and RH ARM switches-As
desired.
NOTE
A rocket induced engine surge is
characterized by engine torque
fluctuations rising TGT, and an
audible change in the engine noise.
A lateral airframe oscillation may be
present after the rockets have fired.
When firing multiple Mart 66 rockets,
it is normal to see the TGT rise more
than 50 degrees even though no
engine surge occurred.
4. Pilot SMOKE REL switch - Depressed.
4-19. Wing Stores Jettison-Inflight Procedures.
Refer to Chapter 9, Section I.
4-20. BEFORE LANDING CHECK - ALL ARMAMENT.
1. Gunner PLT OVRD switch - OFF.
GPO: 1993 0 - 342-421/62947
PIN: 014865-031
1. Pilot MASTER ARM switch - ARM.
2. Gunner PLT OVRD switch - OFF.
Change 31
4-38
TM 55-1520-234-10
2. Pilot MASTER ARM switch-STBY.
WARNING
Ensure rocket igniter arms are in
contact with firing disk. Igniter arms
provide path to ground thereby
preventing ignition caused by
electromagnetic radiation.
3. TCP-TSU/GUN.
4-21.
BEFORE LEAVING HELICOPTER CHECK ALL ARMAMENT.
3. Rocket igniter arms - In contact with rockets.
1. TOW Missile engaging handle - Up.
2. Wing ejector rack jettison safety pins - Installed.
Change 19
4-39
TM 55-1520-234-10
SECTION Ill. PASSIVE DEFENSE
4-22. WIRE STRIKE PROTECTION SYSTEM.
The wire strike protection system (figure 4-23) consists
of three cutter assemblies, a windshield deflector and a
nose deflector. An upper cutter assembly is mounted on
top of the pilot station, forward of the ADF loop antenna.
A chin cutter assembly is mounted under the nose, just
forward of the gunner station. A lower cutter assembly
is mounted on the forward fuselage, under the
ammunition compartment.
Figure 4-23. Wire Strike Protection System
Change 19
4-40
TM 55-1520-234-10
CHAPTER 5
OPERATING LIMITS AND RESTRICTIONS
Section I. GENERAL
5-1. Purpose.
5-2A.
This chapter identifies or refers to all important
operating limits and restrictions that shall be observed
during ground and flight operations.
a. Any time an operational limit is exceeded an
appropriate entry shall be made on DA Form 2408-13.
Entry shall state what limit or limits were exceeded,
range, time above limits, and any additional data that
would aid maintenance personnel in the maintenance
action that may be required.
5-2. General.
The operating limitations set forth in this chapter are
the direct results of design analysis, tests, and operating
experiences. Compliance with these limits will allow the
pilot to safely perform the assigned missions and to
derive maximum utility from the helicopter. Limits
concerning maneuvers, weight, and center of gravity
limitations are also covered in this chapter.
Exceeding Operational Limits.
b. The instruments in the pilot's station are the
primary reference for determining aircraft operating
limits.
5-3. Minimum Crew Requirements.
a. The minimum crew requirement consists of a
pilot whose station is in the aft cockpit.
b. Deleted.
Section II. SYSTEM LIMITS
5-4. Instrument Markings. (Figure 5-1)
a. Instrument Marking Color Codes. Operating
limitations and ranges are illustrated by the colored
markings which appear on the dial faces of engine, flight
and utility system instruments. RED markings on the
dial faces of these instruments indicate the limit above
or below which continued operation is likely to cause
damage or shorten life. The GREEN markings on
instruments indicate the safe or normal range of
operation. The YELLOW markings on instruments
indicate the range when special attention should be
given to the operation covered by the instrument.
Operation is permissible in the yellow range, provided
no other operating limit is exceeded. White strips
dividing red markings on dial faces provide high and/or
low limitation visibility when operating in the night vision
environment.
b. Instrument Glass Alignment Marks. Limitation
markings consist of strips of semi-transparent color tape
which adhere to the glass outside of an indicator dial.
Change 19
Each tape strip aligns to increment marks on the dial
face so correct operating limits are portrayed. The pilot
should occasionally verify alignment of the glass to the
dial face. For this purpose, all engine instruments have
short, vertical white alignment marks extending from the
bottom part of the dial glass onto the fixed base of the
indicator. These slippage marks appear as a single
vertical line when limitation markings on the glass
properly align with reading increments on the dial face.
However, the slippage marks appear as separate radial
lines when a dial glass has rotated.
5-5. Rotor Limitations.
a. Normal Operating Range. Refer to figure 5-1.
b. Wind Limitations. Helicopter can be started in a
maximum wind velocity of 30 knots or a maximum gust
spread of 15 knots. Gust spreads are not normally
reported. To obtain spread, compare minimum and
maximum wind velocity.
5-1
TM 55-1520-234-10
5-6. Deleted.
Section III. POWER LIMITS
5-7. Engine Limitations. (Figure 5-1)
a. Engine overspeed; an engine overspeed exists
under the following conditions.
(1) When N1 speed exceeds 106 percent.
b. Maximum oil consumption is 0.3 gallon (2.4
pints) per hour.
c. Maximum starter energize time is 35 seconds
with a one minute cooling time between start attempts,
with three attempts in any one hour.
(2) When N2 exceeds 6900 rpm.
(3) When N2 is between 6700 and 6900 rpm
for more than ten seconds with TGT above 750°C.
d. Maximum TGT for environmental control unit
operation is 820°C.
e. 6000 to 6400 rpm N2 transient.
NOTE
The red line at 6600 rpm on the engine
tachometer (figure 5-1) represents the power
on rotor speed limit. Even though an engine
write-up is not required unless the rpm
limits of paragraph 5-7a(2) and (3) are
exceeded, willful operation shall not be
conducted with engine rpm above the red
line limit of 6600 rpm.
5-8. Deleted.
5-9. Deleted.
Change 19
5-2
TM 55-1520-234-10
Figure 5-1. Instrument markings (Sheet 1 of 2)
Change 19
5-3
TM 55-1520-234-10
Figure 5-1. Instrument markings (Sheet 2 of 2)
Change 30
5-4
TM 55-1520-234-10
Section IV. LOADING LIMITS
5-10. Center of Gravity Limitations.
5-11. Weight Limitations.
Center of gravity limits for the aircraft to which this
manual applies and instructions for computation of the
center of gravity are contained in Chapter 6.
a. The maximum gross weight for this helicopter is
10,000 pounds.
NOTE
The lateral cg limits are 2.0 inches (2
inches to the right and left of
centerline of helicopter).
These
limits cannot be exceeded due to
normal weapon firing sequence and
stores jettison procedure.
b. Aircraft with single hydraulic system capability
(collective authority check results) of less than 48 PSI
torque but more than 40 PSI torque may be operated
with restrictions. The aircraft configuration and gross
weight shall be limited such that, in the event of a
hydraulic system failure, a gross weight is achievable
(jettisoning wing stores as appropriate) which does not
exceed that corresponding to a 5 feet IGE hover
capability at the recorded torque value.
5-10A. Turbulence Restrictions.
5-12. Deleted.
Intentional flight into severe or extreme turbulence
is prohibited
.
Section V. AIRSPEED LIMITATIONS
5-13. Airspeed Limitations.
a. Refer to Figure 5.3 for forward airspeed limits.
b. Sideward flight limit is 35 KIAS.
c. Rearward flight limit is 30 KIAS.
d. Airspeed limit for indicated torque greater than
50 psi is 100 KIAS. Airspeed limit for indicated torque
greater than 35 psi is 150 KIAS.
g. Maximum steady-state airspeed with SCAS
OFF is 100 knots. With SCAS inoperative and at
airspeed in excess of 100 KIAS, uncommanded roll,
pitch, and yaw oscillations will occur. The magnitude of
the oscillation will increase as airspeed increases. Due
to the nature of the oscillation, there is a tendency to
introduce pilot induced oscillations which further
aggravate the condition.
Additionally, high power
settings should be avoided when operating at airspeeds
between 60 and 100 KIAS with inoperative roll and yaw
SCAS channel because of instability.
h. Deleted.
e. Maximum airspeed for TOW missile firing is 150
knots.
f. Steady state autorotation limit is 120 KIAS.
Change 27
Figure 5-1A. Deleted.
5-5
TM 55-1520-234-10
5-14. Deleted.
5-15. Canopy Door Limitations.
The canopy door shall not be opened in flight except as
outlined in emergency procedures, Chapter 9.
Section VI. MANEUVERING UMITS.
5-16. Prohibited Maneuvers.
a. Abrupt inputs of flight controls cause excessive
main rotor flapping, which may result in mast bumping
and must be avoided.
b. Intentional maneuvers beyond attitudes of ±30
degrees in pitch or ±60 degrees in roll are prohibited.
c. Intentional flight below +0.5 "G's" is prohibited.
Refer to "Low G Maneuvers," Chapter 8, paragraph 870.
f. Diving flight as defined in Chapter 8 and FC 1213 is prohibited for aircraft equipped with B540 Main
Rotor Blades. Maintenance test flight maneuvers IAW
the maintenance test night manuals are not affected and
will continue as required.
5-16A. Slope Landing and Takeoff Limitation.
Slope operations shall be limited to slopes of 8
degrees or less.
CAUTION
Caution is to be exercised for slopes
greater than 5 degrees since rigging,
loading, terrain, and wind conditions
may
alter
the
slope
landing
capability.
d. Practice autorotations and/or rapid throttle
setting reduction at airspeeds greater than 150 KIAS are
prohibited when indicated engine torque pressure is
greater than 35 psi.
e. The speed for any and all maneuvers shall not
exceed the airspeeds as stated on the Airspeed
Operating Limit Chart, Figure 5-3.
All data on pages 5-6A and 5-6B, including Figure 5-2, is deleted.
Change 30
5-6
TM 55-1520-234-10
Figure 5-3. Airspeed operating limits chart
5-7
TM 55-1520-234-10
Section VII. ENVIRONMENTAL RESTRICTIONS
5-17. Environmental Restrictions.
a. This helicopter is not qualified for flight under
instrument meteorological conditions.
b. Environmental restrictions; refer to Sections III
and V of Chapter 8.
Section VIII. HEIGHT VELOCITY
5.18. Deleted.
All data on page 5-9/5-10. Including Figure 5.4 Is deleted.
Change 19
5-8
TM 55-1520-234-10
Figure 5-4. Minimum height for safe landing after engine failure chart
Change 9
5-9/(5-10 blank)
TM 55-1520-234-10
CHAPTER 6
WEIGHT/BALANCE AND LOADING
Section I. GENERAL.
6-1. General.
Chapter 6 contains sufficient instructions and data so
that an aviator knowing the basic weight and moment of
the helicopter can compute any combination of weight
and balance.
6-2. Classification of Helicopter.
For the purpose of clarity, Army AH-IS helicopters are in
class 2. Additional directives governing weight and
balance of class 2 helicopter forms and records, are
contained in AR 95-3 and TM 55-1500-342-23.
6-3. Helicopter Station Diagram.
Figure 6-1 shows the helicopter reference datum lines,
fuselage stations, buttlines, and waterlines. The primary
purpose of the figure is to aid personnel ill the
computation of helicopter weight/balance and loading.
b. Use. From the figures contained in this chapter.
weight and moment are obtained for all variable load
items and are added to the current basic weight and
moment (DD Form 365C) to obtain the gross weight and
moment.
(1) The gross weight and moment are
checked on figure 6-8 to determine the approximate
center of gravity (cg).
(2) The effect on cg by the expenditures in
flight of such items as fuel, ammunition, etc., may be
checked by subtracting the weights and moments of
such items from the takeoff weight and moment and
checking the new weight and moment on the Loading
Limits Chart.
(3) If the weight and moment lines do not
intersect, the cg is not within the flight limits.
NOTE
This check should be made to
determine whether or not the cg will
remain within limits during the entire
flight.
6-4. Loading Charts.
a. Information. The loading data contained in this
chapter are intended to provide information necessary to
work a loading problem for the helicopters to which this
manual is applicable.
Change 30
6-1
TM 55-1520-234-10
Figure 6-1. Helicopter station diagram
All data on page 6-3, including figure 6-1 (Sheet 2 of 2) deleted.
Change19
6-2
TM 55-1520-234-10
Section II. WEIGHT AND BALANCE
6-5. Weight and Balance Records.
Weight and Balance forms are maintained
in the helicopter historical file. Refer to
Section II of TM 55-1500-342-23 for
information on DD Forms 365-1, 3, and .4.
Section III. PERSONNEL
6-6. Personnel Moments.
Refer to figure 6-2 to compute pilot and
gunner moments.
Section IV. MISSION EQUIPMENT
6-7. Weight and Balance Loading Data.
Refer to figures 6-3 through 6-6 for the
quantity, weight, and moment of each
armament item up to maximum load.
Section V. CARGO LOADING
Not Applicable
6-8. Fuel Data.
Section VI. FUEL/OIL
6-9. Oil Data.
For weight and balance purposes, oil is considered a
part of aircraft basic weight.
Refer to figure 6-7 for fuel quantity, weight, and
moment.
Section VII. ALLOWABLE LOADING
6-10. Allowable Loading.
Refer to figure 6-8 for allowable loading limits.
Change 19
6-4
TM 55-1520-234-10
Figure 6-2. Personnel Moment Chart
Change 30
6-5
TM 55-1520-234-10
M151 WARHEAD/M423 FUSE
(10 POUND WARHEAD WITH POINT DETONATING FUSE)
M159C POD*
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
Rockets
(Number)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
152
173
193
214
234
255
275
296
316
337
357
378
398
419
439
460
480
501
521
542
*S/N 004041 & SUB
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
302
343
383
423
463
603
543
583
623
663
703
744
784
824
864
904
944
984
1024
1084
311
353
394
435
477
518
559
601
642
683
725
766
807
850
890
933
973
1016
1057
1099
277
318
358
398
438
478
518
558
598
638
678
719
759
799
839
879
919
959
999
1039
285
326
368
409
450
492
533
574
616
667
698
740
781
823
864
906
947
990
1030
1073
M200A1 POD
139
160
180
201
221
242
262
283
303
324
344
365
385
406
426
447
467
488
508
529
ROCKETS @ 20.5 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 1 of 23)
Change 9
6-6
TM 55-1520-234-10
Rockets
(Number)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
*S/N 004041 & SUB
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
M151 WARHEAD/M429 FUSE
(10 POUND WARHEAD WITH PROXIMITY FUSE)
M159C POD*
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
152
302
311
173
343
353
194
384
395
214
424
437
235
465
478
256
505
520
277
546
562
298
587
604
318
627
646
339
667
688
360
708
730
381
749
771
402
790
813
422
830
856
443
871
898
464
912
941
485
952
984
506
993
1026
526
1033
1109
547
1074
1151
M200A1 POD
139
160
181
201
222
243
264
285
305
326
347
368
389
409
430
451
472
493
513
534
277
318
359
399
440
480
521
562
602
642
683
724
765
805
846
887
927
968
1008
1049
ROCKETS @ 20.8 LBS. EACH
285
327
369
411
452
494
536
578
620
662
704
745
787
829
872
915
957
1000
1040
1083
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 2 of 23)
Change 9
6-7
TM 55-1520-234-10
XM229 WARHEAD/,M423 FUSE
(17 POUND WARHEAD WITH POINT DETONATING FUSE)
M159C POD*
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
152
302
311
180
355
366
208
408
420
236
461
475
264
514
529
292
567
584
319
620
638
347
672
693
375
725
747
403
778
802
431
831
856
459
884
911
487
937
965
515
989
543
1042
571
1095
598
1148
626
1201
654
1254
682
1306
M200A1 POD
139
277
285
167
330
340
195
383
394
223
436
449
251
489
503
279
542
558
306
595
612
334
647
667
362
700
721
390
753
776
418
806
830
446
859
885
474
912
939
502
964
530
1017
558
1070
585
1123
613
1176
641
1229
669
1281
Rockets
(Number)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
[email protected] 27.9 LBS. EACH
*S/N 004041 & SUB
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 3 of 23)
Change 9
6-8
TM 55-1520-234-10
XM229 WARHEAD M429 FUSE
(17 POUND WARHEAD WITH PROXIMITY FUSE)
M159C PODS*
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
Rockets
(Number)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
152
180
208
237
265
293
321
349
378
406
434
462
490
519
547
575
603
631
660
688
302
356
409
462
516
569
622
676
729
782
835
889
942
995
1049
1102
1155
1209
1262
1315
311
366
421
476
531
586
641
696
751
806
861
916
971
M200A1 POD
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
139
167
195
224
252
280
308
336
365
393
421
449
477
506
534
562
590
618
647
675
277
331
384
437
491
544
597
651
704
757
801
864
917
970
1024
1077
1130
1184
1237
1290
[email protected] 28.2 LBS. EACH
*S/N 004041 & SUB
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 4 of 23)
Change 9
6-9
285
340
395
450
505
560
615
670
725
780
835
890
945
TM 55-1520-234-10
WDU-4A/A (FLECHETTE) WARHEAD
(9.3 POUND WARHEAD WITH DECELERATION ACTUATED FUSE)
M159C PODS*
Weight (Pounds)
Pod & No. of
Rockets Indicated
Rockets
(Number)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
*S/N 004041 & SUB
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
LOCATION ON WING
Inboard Moment/100
152
172
192
213
233
253
273
293
314
334
354
374
394
415
435
455
475
495
516
536
Outboard Moment/100
302
342
381
421
460
500
539
578
618
657
697
736
776
815
855
894
933
973
1012
1052
311
352
393
433
474
515
555
596
636
677
718
758
799
842
883
923
963
1004
1046
1087
277
317
356
395
435
475
515
554
593
633
673
713
752
792
831
871
910
950
990
1029
285
326
366
407
448
488
529
570
610
651
692
732
773
815
856
896
937
977
1020
1061
M200A1 POD
139
159
179
200
220
240
260
280
301
321
341
361
381
402
422
442
462
482
503
523
ROCKETS @ 20.2 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 5 of 23)
Change 9
6-10
TM 55-1520-234-10
Rockets
(Number)
0
1
2
3
4
5
6
7
M151 WARHEAD/M423 FUSE
(10 POUND WARHEAD WITH POINT DETONATING FUSE )
M157A POD
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Momemt/100
Outboard Moment/100
57
78
98
119
139
160
180
201
113
152
191
230
269
308
347
386
116
157
197
237
278
318
358
398
134
174
214
254
294
334
374
414
138
179
221
262
303
345
386
427
M157B POD
0
1
2
3
4
5
6
7
67
88
108
129
149
170
190
211
ROCKETS @ 20.5 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 6 of 23)
Change 9
6-10A
TM 55-1520-234-10
Rockets
(Number)
0
1
2
3
4
5
6
7
M151 WARHEAD/M423 FUSE
(10 POUND WARHEAD WITH POINT DETONATING FUSE)
M158 POD
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Momemt/100
Outboard Moment/100
42
62
83
103
124
144
165
185
83
122
162
202
241
281
320
360
85
126
167
208
249
290
330
371
95
136
176
216
256
296
336
376
98
140
181
223
264
305
347
388
M158A-1 POD
0
1
2
3
4
5
6
7
48
69
89
110
130
151
171
192
ROCKETS @ 20.5 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 7 of 23)
Change 9
6-10B
TM 55-1520-234-10
M151 WARHEAD/M423 FUSE
(10 POUND WARHEAD WITH POINT DETONATING FUSE)
M1598 POD
Weight (Pounds)
Pod & No. of
Rockets Indicated
Rockets
(Number)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
118
139
159
180
200
221
241
262
282
303
323
344
364
385
405
426
446
467
487
508
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
130
151
171
192
212
233
253
274
294
315
335
356
376
397
417
438
458
479
499
520
LOCATION ON WING
Inboard Moment/100
Outboard Moment/100
234
273
312
351
390
429
468
507
546
585
624
663
702
741
780
819
858
897
936
241
281
321
362
402
442
483
523
563
603
644
684
724
781
821
864
904
947
988
1030
259
299
340
380
420
460
500
540
580
620
660
700
267
309
350
391
433
474
515
556
598
639
680
722
763
805
846
888
929
971
1012
1055
M159C * POD
PRIOR TO S/N 004040
741
781
821
861
901
941
981
1021
ROCKETS @ 20.5 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 8 of 23)
Change 9
6-10C
TM 55-1520-234-10
Rockets
(Number)
M151 WARHEAD/M429 FUSE
(10 POUND WARHEAD WITH PROXIMITY FUSE)
M157A POD
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
0
1
2
3
4
5
6
7
57
78
99
119
140
161
182
203
113
152
192
231
271
311
350
390
116
157
198
239
280
320
361
402
0
1
2
3
4
5
6
7
67
88
109
129
150
171
192
213
M157B POD
134
174
215
255
296
337
377
418
138
180
222
263
305
347
389
431
ROCKETS @20.8 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 9 of 23)
Change 9
6-10D
TM 55-1520-234-10
M151 WARHEAD/M429 FUSE
(10 POUND WARHEAD WITH PROXIMITY FUSE)
M158 POD
Rockets
(Number)
0
1
2
3
4
5
6
7
Weight (Pounds)
Pod & No. of
Rockets Indicated
LOCATION ON WING
Inboard Moment/100
42
62
83
104
125
146
166
187
Outboard Moment/100
83
123
163
203
243
283
323
363
85
127
168
209
251
292
333
375
M158A-1 POD
0
1
2
3
4
5
6
7
48
69
90
110
131
152
173
194
95
136
177
217
258
298
339
380
ROCKETS @ 20.8 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 10 of 23)
Change 9
6-10E
98
140
182
224
266
308
350
292
TM 55-1520-234-10
M151 WARHEAD/M429 FUSE
110 POUND WARHEAD WITH PROXIMITY FUSES
M159B POD
Weight (Pounds)
Pod & No. of
Rockets Indicated
118
139
160
180
201
222
243
264
284
305
326
347
368
388
409
430
451
472
492
513
Rockets
(Number)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
*PRIOR TO S/N 004040
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
16
16
17
18
19
LOCATION ON WING
Inboard Moment/100
234
273
313
352
392
431
471
610
550
589
629
668
708
748
787
827
866
906
945
985
Outboard Moment/100
241
282
322
363
404
445
486
526
567
608
649
689
730
787
829
872
915
957
998
1040
M159C* POD
130
151
172
192
213
234
255
276
296
317
338
359
380
400
421
442
463
484
504
525
259
300
341
381
422
462
503
544
584
625
665
706
747
787
828
888
909
950
990
1031
ROCKETS @ 20.8 LBS. EACH
267
309
351
393
435
476
518
560
602
644
686
727
769
811
854
896
939
982
1022
1065
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 11 of 23)
Change 9
6-10F
TM 55-1520-234-10
XM229 WARHEAD/M423 FUSE
(17 POUND WARHEAD WITH POINT DETONATING FUSE)
M1570 POD
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
Rockets
(Number)
0
1
2
3
4
5
6
7
67
95
123
151
179
207
234
262
*PRIOR TO S/N 004040
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
134
187
239
292
345
398
451
504
138
192
247
301
356
411
465
520
M159C*POD
130
158
186
214
242
270
297
325
353
381
409
437
465
493
521
259
312
365
418
471
524
576
629
682
735
788
841
893
946
999
ROCKETS @ 27.9 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 12 of 23)
Change 9
6-10G
267
322
376
431
485
540
594
649
703
757
812
866
921
976
1031
TM 55-1520-234-10
XM229 WARHEAD/M429 FUSE
(17 POUND WARHEAD WITH PROXIMITY FUSE)
M157B POD
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
67
134
138
95
187
193
123
240
248
152
294
303
180
347
358
208
400
413
236
453
468
264
507
523
Rockets
(Number)
0
1
2
3
4
5
6
7
*PRIOR TO S/N 004040
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
M159C* POD
130
158
186
215
243
271
299
327
356
384
412
440
468
497
525
259
313
366
419
473
526
579
632
686
739
792
846
899
952
1006
267
322
377
432
487
542
597
652
707
762
817
872
927
ROCKETS @ 28.2 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 13 of 23)
Change 9
6-10H
TM 55-1520-234-10
Rockets
(Number)
0
1
2
3
4
5
6
7
XM229 WARHEAD/M423 FUSE
(17 POUND WARHEAD WITH POINT DETONATING FUSE)
M158 POD
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
42
70
97
125
153
181
209
237
83
135
187
239
291
343
395
447
85
139
193
247
301
354
408
462
95
148
201
254
307
360
413
465
98
153
208
262
317
371
426
480
M158A-1 POD
0
1
2
3
4
5
6
7
48
76
104
132
160
188
215
243
ROCKETS @ 27.9 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 14 of 23)
Change 9
6-10J
TM 55-1520-234-10
Rockets
(Number)
0
1
2
3
4
5
6
7
XM229 WARHEAD/M429 FUSE
(17 POUND WARHEAD WITH PROXIMITY FUSE)
M158 POD
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
42
83
85
70
135
140
98
188
194
126
241
248
154
293
303
183
346
357
211
398
429
239
451
465
M158A-1 POD
0
1
2
3
4
5
6
7
48
76
104
133
161
189
217
245
95
149
202
255
309
362
415
469
98
153
209
264
319
374
479
484
ROCKETS @ 28.2 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 15 of 23)
Change 9
6-10K
TM 55-1520-234-10
WDU-4A/A (FLECHETTE) WARHEAD
(9.3 POUND WARHEAD WITH DECELERATION ACTUATED FUSE)
Rocket*
(Number)
0
1
2
3
4
5
6
7
M157A POD
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
57
113
116
77
151
156
97
190
196
118
228
235
138
266
275
158
305
315
178
343
354
198
382
394
M1578 POD
0
1
2
3
4
5
6
7
67
87
107
128
148
168
188
208
134
173
213
252
291
331
370
410
138
179
219
260
301
341
382
423
ROCKETS @ 20.2 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 16 of 23)
Change 9
6-10L
TM 55-1520-234-10
Rockets
(Number)
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
WDU-4A/A (FLECHETTE) WARHEAD
(9.3 POUND WARHEAD WITH DECELERATION ACTUATE FUSE)
M158 POD
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
42
62
82
102
122
143
163
183
83
122
161
200
238
277
316
355
85
126
166
206
246
286
326
366
M158A-1 POD
95
98
135
139
174
180
214
220
253
261
293
302
332
343
371
383
ROCKETS @ 20.2 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 17 of 23)
48
68
88
109
129
149
169
189
Change 9
6-10M
TM 55-1520-234-10
WDU-4A/A (FLECHETTE WARHEAD
(9.3 POUND WARHEAD WITH DECELERATION ACTUATED FUSE
M159B POD
Weight (Pounds)
Pod & No. of
Rockets Indicated
118
138
158
179
199
219
239
259
280
300
320
340
360
381
401
421
441
461
482
502
Rockets
(Number)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
*PRIOR TO S/N 004040
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
LOCATION ON WING
Inboard Moment/100
234
272
311
349
387
426
464
502
541
579
618
656
694
733
771
809
848
886
925
963
Outboard Moment/100
241
281
320
360
399
439
479
518
558
597
637
676
716
M159C* POD
130
150
170
191
211
231
251
271
292
312
332
352
372
393
413
433
453
473
494
514
259
299
338
378
417
457
496
535
575
614
654
693
733
772
811
851
890
930
969
1009
267
308
349
389
430
470
511
552
592
633
674
714
755
ROCKETS @ 20.2 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 18 of 23)
Change 9
6-10N
TM 55-1520-234-10
Rockets
(Number)
0
1
2
3
4
5
6
7
M151 WARHEAD/M423 FUSE
(10 POUND WARHEAD WITH POINT DETONATING FUSE)
M260 LAUNCHER
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
35
70
72
56
111
114
76
151
156
97
192
198
117
233
240
138
274
282
158
314
324
179
355
366
M261 LAUNCHER
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
80
101
121
142
162
183
203
224
244
265
285
306
326
347
367
388
408
429
449
470
159
200
240
281
322
363
403
444
485
526
566
607
648
689
729
770
811
851
892
933
164
206
248
290
332
374
416
458
500
542
584
626
668
710
752
794
836
878
920
962
ROCKETS @ 20.5 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 19 of 23)
Change 19
6-10P
TM 55-1520-234-10
M151 WARHEAD/M429 FUSE
110 POUND WARHEAD WITH PROXIMITY FUSE)
Rockets
(Number)
0
1
2
3
4
5
6
7
M260 LAUNCHER
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
35
70
72
56
111
115
77
152
157
97
194
200
118
235
242
139
276
285
160
317
327
181
359
370
M261 LAUNCHER
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
80
101
122
142
163
184
205
226
246
267
288
309
333
350
371
392
413
434
454
475
159
200
241
283
324
365
406
448
489
530
571
613
654
695
736
778
819
860
901
943
164
207
249
292
334
377
419
462
504
547
589
632
674
717
759
802
844
887
929
972
ROCKETS @ 20.8 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 20 of 23)
Change 19
6-10Q
TM 55-1520-234-10
M229 WARHEAD/M423 FUSE
(17 POUND WARHEAD WITH POINT DETONATING FUSE)
Rockets
(Number)
0
1
2
3
4
5
6
7
M260 LAUNCHER
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
35
63
91
119
147
175
202
230
70
124
177
231
285
339
392
446
72
127
183
238
294
349
405
460
159
213
266
320
374
428
481
535
589
642
696
750
803
857
911
965
1018
1072
1126
1179
164
219
275
330
386
441
496
552
607
663
718
774
829
M261 LAUNCHER
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
80
108
136
164
192
220
247
275
303
331
359
387
415
443
471
499
526
554
582
610
ROCKETS @ 27.9 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 21 of 23)
Change 19
6-10R
TM 55-1520-234-10
Rockets
(Number)
M229 WARHEAD/M429 FUSE
(17 POUND WARHEAD WITH PROXIMITY FUSE)
M260 LAUNCHER
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
0
1
2
3
4
5
6
7
35
63
91
120
148
176
204
232
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
80
108
136
165
193
221
249
277
306
334
362
390
418
447
475
503
531
559
588
616
70
126
178
232
286
341
395
449
72
128
184
240
296
352
408
463
159
213
268
322
376
430
484
538
593
647
701
755
809
863
918
972
1026
1080
1134
1188
164
220
276
332
388
444
499
555
611
667
723
779
835
M261 LAUNCHER
ROCKETS @ 28.2 LBS. EACH
Figure 6-3. Folding fin aerial rocket (2.75 inch) moment table (Sheet 22 of 23)
Change 19
6-10S
‘,
TM 55-1520-234-10
WDU-4A/A (FLECHETTE) WARHEAD
(9.3 WARHEAD WITH DECELERATING ACTUATED FUSE)
Rockets
(Number)
0
1
2
3
4
5
6
7
M260 LAUNCHER
Weight (Pounds)
LOCATION ON WING
Pod & No. of
Rockets Indicated
Inboard Moment/100
Outboard Moment/100
35
55
75
96
116
136
156
176
70
110
150
190
230
270
310
350
72
113
154
196
237
278
320
361
M261 LAUNCHER
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
80
100
120
141
161
181
201
221
242
262
282
302
322
343
363
383
403
423
444
464
159
199
239
279
319
359
400
440
480
520
560
600
640
680
720
760
800
840
880
920
ROCKETS @ 20.2 LBS. EACH
Figure 6-3. Holding fin aerial rocket (2.75 inch) moment table (Sheet 23 of 23)
Change 19
6-10T
164
205
247
288
329
371
412
453
494
536
577
618
660
701
742
783
825
866
907
949
TM 55-1520-234-10
7.62 MM (LINKED) FOR GAU-2B/A
Weight (Lbs)
For No.
of Rounds
Rounds
Indicated
Moment/100
(Number)
21
16
250
42
33
500
63
49
750
83
65
1000
103
81
1250
123
98
1500
142
114
1750
161
130
2000
179
146
2250
197
163
2500
215
179
2750
232
195
3000
250
211
3250
266
228
3500
283
244
3750
299
260
4000
40MM GRENADES FOR M129
Weight (Lbs)
For No.
Rounds
of Rounds
(Number)
Indicated
Moment/100
21
19
25
43
38
50
64
57
75
86
76
100
107
95
125
129
114
150
150
133
175
172
152
200
193
171
225
215
190
250
7.62MM AMMO (LINKED)@
0.065 LBS. EACH
[email protected] 0.76 LBS. EACH
7.62MM (LINKEDLESS) FOR M18
Weight (Lbs)
Inboard Wing
For No.
Position (Only(
Rounds
of Rounds
(Number)
Indicated
Moment/100
481
245
0
492
251
100
503
256
200
514
262
300
526
267
400
537
273
500
548
278
600
559
284
700
570
289
800
581
295
900
300
592
1000
603
306
1100
615
311
1200
626
317
1300
637
1400
322
648
328
1500
7.62MM AMMO (LINKLESS)@
0.055 LBS. EACH
Figure 6-4. Ammunition moment table
Change 9
6-11
TM 55-1520-234-10
BGM-71 OR BTM-71 A TOW MISSILE
OUTBOARD WING POSITION ONLY
ITEM
(1) Launcher
(2) Launchers
(1) Tube
(2) Tubes
(3) Tubes
(4) Tubes
(1) Missile
(2) Missiles
(3) Missiles
(4) Missiles
WEIGHT
(POUNDS)
60
120
UPPER LAUNCHER
MOMENT/100
123
246
LOWER LAUNCHER
MOMENT/100
122
244
13
26
39
52
26
52
78
104
26
52
78
103
41
82
123
164
82
164
246
328
82
163
245
326
Figure 6-5. TOW Missile moment table
WHITE SMOKE GRENADES
COLORED SMOKE GRENADES
IN XM118 POD
IN XM118 POD
Weight (Lbs)
Outboard
Weight (Lbs)
Outboard
Pod & No. of
Location Only
Pod & No. of
Location Only
Grenades
Grenades
Number
Indicated
Moment/100
Number
Indicated
Moment/100
33
17
0
33
17
0
35
18
1
37
19
1
37
19
2
40
21
2
39
20
3
43
22
3
41
21
4
47
24
4
43
22
5
50
26
5
45
23
6
54
28
6
47
24
7
57
29
7
49
25
8
61
31
8
51
26
9
65
33
9
54
27
10
69
35
10
56
28
11
72
36
11
58
29
12
76
38
12
WHITE SMOKE GRENADES
1.75 LBS. EACH
COLORED SMOKE GRENADES
1.0 LBS. EACH
Figure 6-6. Smoke grenade moment table
Change 15
6-12
TM 55-1520-234-10
Figure 6-7. Fuel moment chart
6-13
TM 55-1520-234-10
Figure 6-8. Center of gravity limit chart (Sheet 1 of 2)
Change 9
6-14
TM 55-1520-234-10
Figure 6-8. Center of gravity limit chart (Sheet 2 of 2).
Change 30
6-15
TM 55-1520-234-10
Section VIII. DD FORM 365
All data on pages 6-16 through 6-20, including paragraphs 6-11 through 6-13 and figures 6-9 through 6-11, is deleted.
Change 19
6-16
TM 55-1520-234-10
(12) Check the weight figure opposite reference 10
against the "Gross Weight Takeoff' in the "Limitations"
table.
Check the weight and moment/100 figures
opposite reference 10 on figure 6-8 to ascertain that the
cg is within the allowable limits.
(13) Reference 11 - if changes in amount of
distribution of load are required, indicate necessary
adjustments by proper entries in the "Corrections" table
in lower left corner of the form as follows:
(a) Subtract the weight and moment of the
fuel estimated to remain at landing from the weight and
moment of the fuel loaded at takeoff.
(a) Enter a brief description of the adjustment
made in the column marker "Item".
(b) Add all the weight and moment decreases
and insert the totals in the space opposite "Total Weight
Removed".
(c) Add all the weight and moment increases
and insert the totals in the space opposite "Total Weight
Added".
(d) Subtract the smaller from the larger of the
two totals and enter the difference (with applicable plus
or minus sign) opposite "Net Difference".
(e) Transfer these net difference figures to
the spaces opposite reference 11.
(14) Reference 12 - Enter the sum of, or the
difference between, reference 10 and reference 11.
Recheck to ascertain that these figures do not exceed
allowable limits.
(15) Reference 13 - By referring to figure 68
determine the takeoff cg position. Enter this figure in
the space provided opposite "Takeoff CG".
(16) Reference 14 - Estimate the weight of
ammunition (not including weight of cases and links if
retained), fuel, and any other items which may be
expended before landing. Enter figures together with
moment/100 in the spaces provided. To estimate the
amount of fuel expended, perform the following
calculation:
Fuel at takeoff
(b) Enter the above result in section 14 of DD
Form 365F.
EXAMPLE
FueI estimated to
remain at landing
EXAMPLE
Fuel expended
(enter in section 14
of Form 365F)
WEIGHT
MOMENT
206
1400
2900
200
440
WEIGHT
MOMENT
1200
2460
NOTE
Do not consider reserve fuel as
expended
when
determining
ESTIMATED LANDING CONDITION.
(17) Reference 15 - Enter the difference in weights
and moment/100 between reference 12 and the total of
reference 14.
(18) Reference 16 - By again referring to figure 6-8,
determine the estimated landing cg position. Enter the
figure opposite "ESTIMATED LANDING CG".
(19) The necessary signatures must appear at the
bottom of the form.
Page 6-18 Including Figure 6-9 deleted
Change 15
GAL
6-17
TM 55-1520-234-10
CHAPTER 7
PERFORMANCE DATA
Section I. INTRODUCTION
unfamiliar areas or at extreme
conditions. The data may also be
The purpose of this chapter is to provide the best
used inflight, to establish unit or
available performance data for the AH-1S helicopter.
area standing operating procedures,
Regular use of this information will enable you to
and to inform ground commanders
receive maximum safe utilization from the aircraft.
of performance/risk tradeoffs.
Although maximum performance is not always required,
NOTE
regular use of this chapter is recommended for the
All performance data presented in
following reasons.
this chapter is based on operation
a. Knowledge of your performance margin will
with B540 main rotor blades
allow you to make better decisions when unexpected
installed. Data presented may be
conditions or alternate missions are encountered.
used when planning flights for
b. Situations requiring maximum performance will
aircraft equipped with K747 main
be more readily recognized.
rotor blads. Actual performance with
c. Familiarity with the data will allow performance
K747 main rotor blades will be
to be computed more easily and quickly.
superior to that depicted on the
charts.
d. Experience will be gained in accurately
estimating the effects of variables for which data are not
presented.
7-2. Chapter 7 Index.
7-1. Purpose.
The following index contains a list of the sections and
their titles, the figure numbers, subjects and page
numbers of each performance data chart contained in
this chapter.
NOTE
The information provided in this
chapter is primarily intended for
mission planning and is most useful
when
planning
operations
in
Index
Section
Page
No.
Subject
I
Introduction .................................................................................................................................... 7-1
II
Performance Planning ................................................................................................................... 7-5
Figure 7-1 Deleted
Figure 7-2 Temperature Conversion Chart ............................................................................. 7-8
III
Power Available ............................................................................................................................. 7-9
Figure 7-3 Maximum Torque (30-Minute Operation) Chart .....................................................7-11
Figure 7-4 Torque Available (Continuous Operation) Chart
Sheet (1 of 2) ECU OFF ...............................................................................................7-12
Sheet (2 of 2) ECU ON .................................................................................................7-13
IV
Hover ............................................................................................................................................ 7-9
Figure 7-5 Hover (Torque Required) Chart .............................................................................7-14A
Figure 7-5A. Directional Control Margin Chart ........................................................................7-14B
Change 19
7-1
TM 55-1520-234-10
Index (Cont)
Section
V
Page
No.
Subject
Takeoff
...................................................................................................................................7-10A
Figure 7-6 Takeoff........................................................................................................... 7-16
VI
Climb Performance ....................................................................................................................7-10A
Figure 7-7 Climb Performance (Max Torque) Chart ........................................................ 7-17
VII
VIII
Cruise ........................................................................................................................................
Cruise Chart, 4 TOW Missiles Configuration
Sheet 1 of 24, Pressure Altitude Sea Level to 6000 Ft, FAT = -30 C ..........................
Sheet 2 of 24, Pressure Altitude 8000 Ft to 14000 Ft, FAT = -30 C ............................
Sheet 3 of 24, Pressure Altitude Sea Level to 6000 Ft, FAT = -15 C ..........................
Sheet 4 of 24, Pressure Altitude 8000 Ft to ,14000 Ft, FAT = -15 C ...........................
Sheet 5 of 24, Pressure Altitude Sea Level to 6000 Ft, FAT = 0 C .............................
Sheet 6 of 24, Pressure Altitude 8000 Ft to 14000 Ft, FAT = 0 C ...............................
Sheet 7 of 24, Pressure Altitude Sea Level to 6000 Ft, FAT = +15 C .........................
Sheet 8 of 24, Pressure Altitude 8000 Ft to 14000 Ft, FAT = +15 C ..........................
Sheet 9 of 24, Pressure Altitude Sea Level to 6000 Ft, FAT = +30 C .........................
Sheet 10 of 24, Pressure Altitude 8000 Ft to 14000 Ft, FAT = +30 C .........................
Sheet 11 of 24, Pressure Altitude Sea Level to 6000 Ft, FAT = +45 C ......................
Sheet 12 of 24, Pressure Altitude 8000 Ft to 14000 Ft, FAT = +45 C ........................
Cruise Chart, 8 TOW Missiles Configuration
Sheet 13 of 24, Pressure Altitude Sea Level to 6000 Ft, FAT = -30 C ........................
Sheet 14 of 24, Pressure Altitude 8000 Ft to 14000 Ft, FAT = -30 C ..........................
Sheet 15 of 24, Pressure Altitude Sea Level to 6000 Ft, FAT = -15 C ........................
Sheet 16 of 24, Pressure Altitude 8000 Ft to 14000 Ft, FAT = -15 C ..........................
Sheet 17 of 24, Pressure Altitude Sea Level to 6000 Ft, FAT = 0 C ...........................
Sheet 18 of 24, Pressure Altitude 8000 Ft to 14000 Ft, FAT = 0 C .............................
Sheet 19 of 24, Pressure Altitude Sea Level to 6000 Ft, FAT = +15 C .......................
Sheet 20 of 24, Pressure Altitude 8000 Ft to 14000 Ft, FAT = +15 C .........................
Sheet 21 of 24, Pressure Altitude Sea Level to 6000 Ft, FAT = +30 C ......................
Sheet 22 of 24, Pressure Altitude 8000 Ft to 14000 Ft, FAT = +30 C ........................
Sheet 23 of 24, Pressure Altitude Sea Level to 6000 Ft, FAT = +45 C ......................
Sheet 24 of 24, Pressure Altitude 8000 Ft to 12000 Ft, FAT = +45 C ........................
Drag ..........................................................................................................................................
7-19
7-21
7-23
7-24
7-25
7-26
7-27
7-28
7-29
7-30
7-31
7-32
7-33
7-34
7-35
7-36
7-37
7-38
7-39
7-40
7-41
7-42
7-43
7-44
7-45
7-46
Figure 7-9 (Sheet 1 of 2) Armament Configurations ........................................................ 7-48
Figure 7-9 (Sheet 2 of 2) Drag Chart .............................................................................. 7-49
IX
Climb-Descent and Landing ...................................................................................................... 7-46
Figure 7-10 Climb-Descent Chart .................................................................................... 7-50
X
Idle Fuel FLOW ......................................................................................................................... 7-47
Figure 7-11 Idle Fuel Flow Chart .................................................................................... 7-51
XI
Airspeed Calibration .................................................................................................................. 7-47
Figure 7-12 Airspeed Calibration Chart ........................................................................... 7-52
Change 2
7-2
TM 55-1520-234-10
7-3. General.
The data presented covers the maximum range
of conditions and performance that can reasonably be
expected. In each area of performance, the effects of
altitude, temperature, gross weight, and other
parameters relating to that phase of flight are presented.
In addition to the presented data, your judgment and
experience will be necessary to accurately obtain
performance under a given set of circumstances. The
conditions for the data are listed under the title of each
chart. The effects of different conditions are discussed
in the text accompanying each phase of performance.
Where practical, data are presented at conservative
conditions. However NO GENERAL CONSERVATISM
HAS BEEN APPLIED. All performance data presented
are within the applicable limits of the aircraft.
etc. until the final variable is read out at the final scale.
In addition to the primary use, other uses of each chart
are explained in the text accompanying each set of
performance charts. Colored registration blocks located
at the bottom and top of each chart are used to
determine it' slippage has occurred during printing. It'
slippage has occurred, refer to chapter 5 for correct
operating limits.
NOTE
An example of an auxiliary use of the
charts referenced above is as
follows: Although the hover chart is
primarily
arranged
to
find
horsepower required to hover, by
entering horsepower available as
horsepower required, maximum skid
height for hover can also be found.
In general, any single variable can be
found if all others are known. Also,
the tradeoffs between two variables
can be found. For example, at a
given density altitude and pressure
altitude, you can find the maximum
gross
weight
capability
air
temperature changes.
7-4. Limits,
Applicable limits are shown on1 the charts -is
red lines. Performance generally deteriorates rapidly
beyond limits. It limits ire exceeded, minimize the
amount and time. Enter the maximum value and time
above limits on DA Form 2408-13 so proper
maintenance action can be taken.
7-5. Use of Charts.
a. Chart Explanation. The first page of- each
section describes the chart(s) and explains its uses.
b. Color Coding. Chart color codes are used 'is
follows.
(1) Green is used for example guidelines.
(2) Red is used for limit lines.
(3) Yellow is used for precautionary or time-limited
operation
c. Reading, the Charts. Tile primary use of each
chart is given in an example and a green guideline is
provided to help you follow the route through the chart.
The use of a straight edge (ruler or page edge) and a
hard fine point pencil is recommended to avoid
cumulative errors. The majority of the charts provide a
standard pattern for use as follows: enter first variable
on top left scale, move right to the second variable,
reflect down at right angles to the third variable. reflect
left at right angles to the fourth variable, reflect down.
Change 30
d. Dashed Line Data. Data beyond conditions for
which tests were conducted are shown as dashed lines
7-6. Data Basis.
The type oft data used is indicated at the bottom
of each performance chart under DATA BASIS. The
applicable report and date of the data are also given.
The data provided generally is based on one of four
categories:
a. Flight Test Data. Data obtained by flight test of
the aircraft by experience flight test personnel at precise
conditions using sensitive calibrated instruments.
b. Derived From Flight Test. Flight test data
obtained on a similar rather than the same aircraft and
series. Gene rally small corrections will have been
made.
7-3
TM 55-1520-234-10
c. Calculated Data. Data based on tests, but not
on flight test of the complete aircraft.
d. Estimated Data. Data based on estimates using
aerodynamic theory or other means but not verified by
flight test.
7-9. Performance Discrepancies.
Regular use of this chapter will allow you to
monitor instruments and other aircraft systems for
malfunction, by comparing actual performance with
planned performance. Knowledge will also be gained
concerning the effects of variables for which data are
not provided, thereby increasing the accuracy of
performance predictions.
7-7. Specific Conditions.
The data presented are accurate only for
specific conditions listed under the title of each chart.
Variables for which data are not presented, but which
may affect that phase of performance, are discussed in
the text. Where data are available or reasonable
estimates can be made, the amount that each variable
affects performance will be given.
7-10. Definitions of Abbreviations.
a. Unless otherwise indicated in the following list of
abbreviations, abbreviations and symbols used in this
manual conform to those established in Military
Standard MILSTD-12, which is periodically revised to
reflect current changes in abbreviations usage.
Accordingly, it may be noted that certain previously
established definitions have been replaced by more
current abbreviations and symbols.
b. Capitalization and punctuation of abbreviations
varies, depending upon the context in which they are
used. In general, lower case abbreviations are used in
text material, whereas abbreviations used in charts and
illustrations appear in full capital letters. Periods do not
usually follow abbreviations; however, periods are used
with abbreviations that could be mistaken for whole
words if the period were omitted.
c. The following list provides definitions for
abbreviations used in this manual.
The same
abbreviation applies for either singular or plural
applications.
7-8. General Conditions.
In addition to the specific conditions, the
following general conditions are applicable to the
performance data.
a. Rigging. All airframe and engine controls are
assumed to be rigged within allowable tolerances.
b. Pilot Technique. Normal pilot technique is
assumed. Control movements should be smooth and
continuous.
c. Aircraft Variation. Variations in performance
between individual aircraft are known to exist; however,
they are considered to be small and cannot be
individually accounted for.
d. Instrument Variation. The data shown in the
performance charts do not account for instrument
inaccuracies or malfunctions.
LIST OF ABBREVIATIONS
Abbreviation
AGL
ALT
AVAIL
C
CAS
CL
CONT
ECU
END
Definition
Abbreviation
Above ground level
Altitude
Available
Celsius
Calibrated airspeed
Centerline
Continuous
Environmental Control Unit
Endurance
F
FAT
FLT
FT
FT/MIN
FWD
∆F
GAL
7-4
Definition
Fahrenheit
Free air temperature
Flight
Foot
Feet per minute
Forward
Increment of equivalent flat
plate drag area
Gallon
TM 55-1520-234-10
LIST OF ABBREVIATIONS (Cont)
Abbreviation
GAL/HR
GRWT
GW
HP
HR
IAS
IGE
IN
IN HG
IR
KIAS
KN
°
OGE
LB
LB/HR
MAX
MIN
MIN
MM
Definition
Gallons per hour
Gross weight
Gross weight
Horsepower
Hour
Indicated airspeed
In ground effect
Inch
Inches of mercury
Infrared
Knots indicated airspeed
Knot
Degree
Out of ground effect
Pound
Pounds per hour
Maximum
Minute
Minimum
Millimeter
Abbreviation
NO.
NM
PRESS
PSIG
R/C
R/D
RPM
SPEC
STA
SQ FT
TAS
TOW
TRANS
USAASTA
VDC
V NE
Definition
Number
Nautical Mile
Pressure
Pounds per square inch gauge
Rate of climb
Rate of descent
Revolutions per minute
Specifications
Station
Square feet
True airspeed
Tube launched optical guided
wire controlled
Transmission
United States Army Aviation
Systems Test Activity
Volts, direct current
Velocity, never exceed
(airspeed limitation)
Section II. PERFORMANCE PLANNING
7-11. Performance Planning.
Refer to FC1-213 Aircrew Training Manual for
preparing the performance planning card (PPC).
7-12. Temperature Conversion.
The temperature conversion chart (figure 7-2) is
arranged so that degrees celsius can be converted
quickly and easily by reading celsius and looking directly
across the chart for fahrenheit equivalent and vice
versa.
All data on pages 7-6 and 7-7, including figure 7-1 and paragraph 7-13 is deleted.
Change 19
7-5
TM 55-1520-234-10
TEMPERATURE CONVERSION CHART
Figure 7-2. Temperature conversion chart
Change 19
7-8
TM 55-1520-234-10
Section III. TORQUE AVAILABLE
7-14. Description.
The torque available charts show the effects of
altitude and temperature on engine torque.
7-15. Chart Differences.
Both free air temperature (FAT) and pressure
altitude affect engine power production. Figures 7-3
through 74 show power available data at both 30 minute
power and maximum continuous power ratings in terms
of the allowable torque as recorded by the torquemeter
(PSIG).
Note
that the power output capability of
the T53-L-703 engine can exceed the
transmission structural limit under
certain conditions. Limits are shown
on the chart (50 PSIG for normal or
continuous operation and 56 PSIG
for hover, takeoff and climb-30
minute limit).
b. Figure 7-4 (sheet 1 of 2) is applicable for
maximum continuous power with the ECU off.
c. Figure 7-4 (sheet 2 of 2) is applicable for
continuous operation (ECU on). It should be noted that
ECU on cost the equivalent of about 10ºC FAT or
approximately 10% power and 4% increase in fuel flow.
7-16. Use of Charts.
The primary use of the charts is illustrated by
the examples. In general, to determine the maximum
power available, it is necessary to know the pressure
altitude and temperature. By entering the upper left side
of the chart at the known pressure altitude, moving right
to the known temperature, then straight down to the
bottom of the lower grid, available torque is obtained.
7-17. Conditions.
a. Figure 7-3 is applicable for maximum power
(always ECU off, 30minute operation).
Charts are based upon speeds of 324 rotor/6600
engine rpm with grade JP-4 fuel. The use of higher
octane grade aviation gasoline will not influence engine
power. Fuel grade of JP-5 will yield the same nautical
miles per pound of fuel and being 6.8 pounds per gallon
will only result in increased fuel capacity.
Section IV. HOVER
7-18. Description
The hover chart (figure 7-5) shows the torque
required to hover at various pressure altitudes, ambient
temperatures, gross weights, and skid heights.
Maximum skid height for hover can also be obtained by
using the torque available from figure 7-3.
(2) Move right to FAT.
(3) Move down to gross weight.
(4) Move left to intersection with maximum power
available (obtained from figure 7-3).
(5) Read predicted maximum skid height. This
height is the maximum hover height.
7-19. Use of Chart.
a. The primary use of the chart is illustrated by the
chart example. In general, to determine the torque
required to hover, it is necessary to know the pressure
altitude. temperature, gross weight and the desired skid
height.
b. In addition to its primary use, the hover chart
can also be used to determine the predicted maximum
hover height, which is needed for use of the takeoff
chart (figure 7-6). To determine maximum hover height,
proceed as follows.
7-19A. Control Margin.
Ten percent pedal margin is considered
adequate for safe directional control. The rearward
airspeed limit is 30 knots and sideward limit is 35 knots
except that directional control is marginal for certain
combinations of relative wind velocity and azimuth
angles (measured clockwise from the nose of the
helicopter).
Figure 7-5A (sheet 2) shows the
combinations of relative wind velocity and azimuth
which may result in marginal directional control. Figure
7-5A (sheet 2) shows the maximum right cross
(1) Enter chart at appropriate pressure altitude.
Change 30
7-9
TM 55-1520-234-10
wind in knots., True airspeed, which one call achieve
and still maintain 10 percent directional control margin
for given gross weight and density altitudes is indicated
on Sheet 1. This figure has zone letters which are to be
used in Conjunction with figure 7-5A (sheet 2). If, for
example, your operating gross weight and density
altitude are such that the point lies in zone C on sheet I
then go to sheet 2. The zone identified by the letter C
shows the wind velocity in knots that one can achieve
while still maintaining a 10 percent directional control
margin (e.g. if the wind were from 45 degrees you
would have 18 knots of wind whereas if from 60 degrees
only 15.4 knots). The left vertical zone lines on sheet 2
represent 10 percent control margin. As you move
Change 30
toward the right vertical line, for that gross weight and
density altitude, the control margin approaches zero.
7-20. Conditions.
The hover chart is based upon calm wind
conditions, a level ground surface, and the use of 324
rotor/6600 engine
rpm.
a. Deleted
7-10
TM 55-1520-234-10
b. Ground Surface. In ground effect hover data is
based upon hovering over a level surface. If the surface
over which hovering will be conducted is known to be
step, uneven, covered with high vegetation, or if the
type of retain is I unknown, the flight should be planned
for out of ground effect hover capability.
Section V. TAKEOFF
7-21. Description.
The takeoff chart (figure 7-6) shows the
distances to clear various obstacle heights. based upon
several hover height capabilities. The upper chart grid
presents data for climb out at a constant 35 knots
INDICATED airspeed. The two tower grids present data
for climbouts 'it various TRUE airspeeds.
NOTE
The hover heights shown on1 the
chart are only a measure of the
aircraft's climb capability and do lot
imply that a higher than normal
hover height should be used during
the actually takeoff.
7-22. Use of Chart.
The primary use of the chart is illustrated by the
chart examples. The main consideration for takeoff
performance is the hovering skid height capability.
which includes the effects of pressure altitude. free air
temperature. gross weight, and torque. Hover height
capability is determined by use of the hover chart, figure
7-5. A hover check can be made to verify the hover
capability. If winds are present, tile hover check may
disclose that the helicopter can actually hover at a
greater skid height than the calculated value, since the
hover chart is based upon calm wind conditions.
7-23. Conditions.
a. Wind. The takeoff chart is based upon calm
wind conditions.
Since surface wind velocity and
direction cannot be accurately predicted, all takeoff
planning should be based upon calm wind conditions.
Takeoff into any prevailing wind will improve the takeoff
performance.
WARNING
A tailwind during takeoff' and
climbout will increase the obstacle
clearance distance and could prevent
a successful takeoff.
b. Power Settings. All takeoff performance data
are based upon the torque used in determining the
hover capabilities in figure 7-5.
Section VI. CLIMB PERFORMANCE
7-24. Deleted,
7-25. Deleted.
7-26. Deleted.
Change 30
7-10A/(7-10B blank)
TM 55-1520-234-10
Figure 7-3. Maximum torque available (30 minute operation) chart
7-11
TM 55-1520-234-10
Figure 7-4. Torque available (Continuous operation) chart (Sheet 1of of 2)
7-12
TM 55-1520-234-10
Figure 7-4. Torque available (Continuous operation) chart (Sheet 2 of 2)
7-13/(7-14 blank)
TM 55-1520-234-10
Figure 7-5. Hover (Torque required ) chart
Change 19
7-14A
TM 55-1520-234-10
Figure 7-5A. Directional Control Margin Chart (Sheet 1 of 2
Change 19
7-14B
TM 55-1520-234-10
DIRECTIONAL CONTROL MARGIN
Figure 7-5A. Directional Control Margin Chart (Sheet 2 of 2)
Change 30
7-15
TM 55-1520-234-10
Figure 7-6. Takeoff chart
7-16
TM 55-1520-234-10
Figure 7-7. Climb performance (Maximum torque - 30 minute operation) chart
7-17/(7-18 blank)
TM 55-1520-234-10
Section VII. CRUISE
7-27. Description.
The cruise charts (figure 7-8, sheet 1 through 24)
show the torque pressure and engine rpm required for
level flight at various pressure altitudes, airspeeds and
gross weights.
presented at opposite sides of each chart. On any
chart, indicated airspeed can be directly converted to
true airspeed (or vice versa) by reading directly across
the chart without regard for other chart information.
Maximum permissible airspeed (VNE) limits appear as
red lines on some charts. If no red line appears, VNE is
above the limits of the chart.
NOTE
b. Torque Pressure. Since pressure altitude -and
temperature are fixed for each chart, torque pressures
vary according to gross weight and airspeed.
The cruise charts are basically
arranged by drag configuration
groupings.
Figures 7-8 sheets 1
through 12 are based upon operation
with 4 TOW missiles. Figure 7-8,
sheets 13 through 24, present
equivalent information for operation
with 8 TOW missiles.
c. Fuel Float. Fuel flow scales are provided
opposite the torque pressure scales. On any chart,
torque pressure may be converted directly to fuel flow
without regard for other chart information. All fuel flow
information is presented ECU off. Add 4%, fuel flow for
ECU on.
7-28. Use of Charts.
The primary use of the charts is : illustrated by the
examples provided in figure 7-8. The first step for chart
use is to select the proper chart. based upon the
planned drag configuration, pressure altitude and
anticipated free air temperature: refer to chapter , index
(paragraph 7-2). Normally, sufficient accuracy can be
obtained by selecting the chart nearest to the planned
cruising attitude and FAT, or the next higher altitude and
FAT (chart Example A, Method 1). If greater accuracy
is required, interpolation between altitudes and or
temperatures will be required (chart Example A, Method
2). You may enter the charts on any side: TAS, IAS,
torque pressure, or fuel flow, and then move vertically or
horizontally to the gross weight, then to the other three
parameters.
Maximum performance conditions are
determined by entering the chart where the maximum
range or maximum endurance and rate of climb line
intersect the appropriate gross weight: then read
airspeed, fuel flow and torque pressure.
For
conservatism, use the gross weight at the beginning of
cruise flight. For greater accuracy on long flights it is
preferable to determine cruise information for several
flight segments in order to allow for decreasing fuel
weight (reduced gross weight).
The following
parameters contained in each chart are further
explained as follows.
a. Airspeed.
True and syndicated airspeeds are
Change 2
d. Maximum Range. The maximum range lines
indicate the combinations of weight and airspeed that
will pronounce the greatest flight range per gallon of fuel
under zero wind conditions. When a maximum range
condition does not appear on a chart it is because the
maximum range specified is beyond the maximum
permissible speed (VNE) in such cases, use VNE cruising
speed to obtain maximum range.
e. Maximum Endurance and Rate of Climb. The
maximum endurance and rate of climb lines indicate the
airspeed for minimum torque pressure required to
maintain level flight for each gross weight, FAT and
pressure altitude. Since minimum torque pressure will
provide minimum fuel flow, maximum flight endurance
will be obtained at the airspeeds indicated
7-29. Conditions.
The cruise charts are leased upon operation at 324
rotor 6600 engine speeds.
a. The charts are based on ECU off.
b. The fuel flow increases approximately 4% with
ECU on.
7-19
TM 55-1520-234-10
EXAMPLE A
WANTED
TORQUE REQUIRED FOR LEVEL FLIGHT, FUEL FLOW, INDICATED AIRSPEED
KNOWN
4 TOW CONFIGURATION
GROSS WEIGHT = 10000 LB
PRESSURE ALTITUDE 1000 FEET
FAT = -30°C
DESIRED TRUE AIRSPEED = 120 KNOTS
METHOD 1 (SIMPLEST)
USE NEXT HIGHEST ALTITUDE AND/OR TEMPERATURE (2000 FEET, -30°C)
ENTER TRUE AIRSPEED AT 120 KNOTS
MOVE RIGHT TO GROSS WEIGHT
MOVE DOWN, READ CALIBRATED TORQUE = 43.0 PSIG
MOVE UP, READ FUEL FLOW = 648 LB/HR
MOVE RIGHT, READ IAS = 130 KNOTS
METHOD 2 (INTERPOLATE)
READ TORQUE, FUEL FLOW, AND IAS ON EACH ADJACENT ALTITUDE AND/OR FAT,
THEN INTERPOLATE BETWEEN ALTITUDE AND FAT
ALTITUDE
SEA LEVEL
2000 FEET
1000 FEET
FAT -°C
-30
-30
-30
TORQUE, PSIG
44.5
43.0
43.8
FUEL FLOW, LB/HR
678
648
663.0
IAS, KNOTS
135
130
132.5
EXAMPLE B
WANTED
SPEED FOR MAXIMUM RANGE
SPEED FOR MAXIMUM ENDURANCE
KNOWN
4 TOW CONFIGURATION
GROSS WEIGHT = 10000 LB
PRESSURE ALTITUDE = 4000 FEET
FAT = -30°C
METHOD
LOCATE (4000 FEET, -30°C) CHART
FIND INTERSECTION OF 10000 LB GROSS WEIGHT LINE
WITH THE MAXIMUM RANGE LINE
TO READ SPEED FOR MAXIMUM RANGE:
MOVE LEFT, READ TAS = 130 KNOTS AND
MOVE RIGHT, READ IAS = 136 KNOTS
FIND INTERSECTION OF 10000 LB GROSS WEIGHT UNE
WITH THE MAXIMUM ENDURANCE LINE
TO READ SPEED FOR MAXIMUM ENDURANCE:
MOVE LEFT, READ TAS = 68.5 KNOTS AND
MOVE RIGHT, READ IAS = 68.0 KNOTS
DATA BASIS:
DERIVED FROM FLIGHT TEST USA ASTA 66-06, APRIL 1970;
MODEL SPEC 104 43, 1 MAY 1974
7-20
TM 55-1520-234-10
Figure 7-8. Cruise chart, 4 TOW, sea level to 6000 feet. -30°C (Sheet 1 of 24)
Change 9
7-21
TM 55-1520-234-10
EXAMPLE D
WANTED
SPEED FOR MAXIMUM RANGE,
TORQUE REQUIRED AND FUEL FLOW AT
MAXIMUM RANGE
KNOWN
4 TOW CONFIGURATION
GROSS WEIGHT = 9000 LB
PRESSURE ALTITUDE = 10000 FEET
FAT = -30°C
METHOD
EXAMPLE C
WANTED
EXCESS TORQUE AVAILABLE FOR CLIMB AT
MAXIMUM CONTINUOUS POWER
KNOWN
4 TOW CONFIGURATION
GROSS WEIGHT = 10000 LB
PRESSURE ALTITUDE = 8000 FEET
FAT = -30°C
LOCATE (10000 FEET, -30°C) CHART
FIND INTERSECTION OF 9000 LB GROSS WEIGHT LINE
WITH THE MAXIMUM RANGE LINE
TO READ SPEED FOR MAXIMUM RANGE:
MOVE LEFT, READ TAS = 131 KNOTS AND
MOVE RIGHT, READ IAS = 122 KNOTS
TO READ TORQUE REQUIRED:
MOVE DOWN, READ TORQUE = 43 PSIG
TO READ FUEL FLOW REQUIRED
MOVE UP, READ FUEL FLOW = 580 LB/HR
METHOD
LOCATE (8000 FEET, -30°C) CHART
FIND INTERSECTION OF 10000 LB GROSS WEIGHT LINE
WITH THE MAXIMUM RATE OF CLIMB LINE
MOVE DOWN, READ TORQUE REQUIRED = 29 PSIG
FIND INTERSECTION OF 10000 LB GROSS WEIGHT LINE
WITH THE CONTINUOUS TRANSMISSION LIMIT LINE
MOVE DOWN, READ TORQUE AVAILABLE = 50 PSIG
EXCESS TORQUE AVAILABLE = (50 -29) = 21 PSIG
EXAMPLE E
WANTED
CALIBRATED TORQUE REQUIRED,
FUEL FLOW AND INDICATED AIRSPEED
KNOWN
4 TOW CONFIGURATION
GROSS WEIGHT = 9000 LB
PRESSURE ALTITUDE = 12000 FEET
FAT = -30°C
TAS = 110 KNOTS
METHOD
ENTER TAS LINE HERE
MOVE RIGHT TO INTERSECTION OF GROSS WEIGHT
MOVE DOWN, READ TORQUE REQUIRED = 34.1 PSIG
MOVE UP, READ FUEL FLOW = 470 LB/HR
MOVE RIGHT, READ IAS = 97 KIAS
7-22
TM 55-1520-234-10
Figure 7-8 Cruise chart, 4 TOW, 8000 feet to 14,000 feet, -30°C (Sheet 2 of 24)
Change 9
7-23
TM 55-1520-234-10
Figure 7-8 Cruise chart, 4 TOW, sea level to 6000 feet, -15°C (Sheet 3 of 24)
Change 9
7-24
TM 55-1520-234-10
Figure 7-8 Cruise chart, 4 TOW, 8000 feet to 14,000 feet, -15°C (Sheet 4 of 24)
Change 9
7-25
TM 55-1520-23410
Figure 7-8 Cruise chart, 4 TOW, sea level to 6000 feet, 0°C (Sheet 5 of 24)
Change 9
7-26
TM 55-1520-23410
Figure 7-8 Cruise chart, 4 TOW, 8000 feet to 14,000 feet, 0oC (Sheet 6 of 24)
Change 9
7-27
TM 55-1520-234-10
o
Figure 7-8 Cruise chart. 4 TOW, sea level to 6000 feet, +15 C (Sheet 7 of 24)
Change 9
7-28
TM 55-1520-234-10
Figure 7-8 Cruise chart, 4 TOW, 8000 feet to 14,000 feet, +15oC (Sheet 8 of 24)
Change 9
7-29
TM 55-1620-23410
o
Figure 7-8 Cruise chart, 4 TOW, sea level to 6000 feet, +30 C (Sheet 9 of 24)
Change 9
7-30
TM 55-1520-234-10
o
Figure 7-8 Cruise chart, 4 TOW, 8000 feet to 14.000 feet, +30 C (Sheet 10 of 24)
7-31
TM 55-1520-234-10
o
Figure 7-8 Cruise chart, 4 TOW, sea level to 6000 feet, +45 C (Sheet 11 of 24)
Change 9
7-32
TM 65-1520-234-10
Figure 7-8 Cruise chart, 4 TOW, 8000 feet to 14,000 feet, +45oC (Sheet 12 of 24)
7-33
TM 55-1520-234-10
Figure 7-8 Cruise chart, 8 TOW, sea level to 6000 feet, -30oC (Sheet 13 of 24)
Change 9
7-34
TM 55-1520-234-10
Figure 7-8. Cruise chart 8 TOW, 8000 feet to 14,000 feet, -30°C (Sheet 14 of 24)
Change 9
7-35
TM 55-1520-234-10
Figure 7-8 Cruise chart, 8 TOW, sea level to 6000 feet, -15°C (Sheet 15 of 24)
Change 9
7-36
TM 55-1520-234-10
Figure 7-8. Cruise chart. 8 TOW, 8000 feet to 14,000 feet. -15°C (Sheet 16 of 24)
Change 9
7-37
TM 55-1520-234-10
Figure 7-8 Cruise chart. 8 TOW, sea level to 6000 feet. 0°C (Sheet 17 of 24)
Change 9
7-38
TM 55-1520-234-10
Figure 7-8 Cruise chart. 8 TOW, 8000 feet to 14,000 feet 0°C (Sheet 18 of 24)
Change 9
7-39
TM 55-1520-234-10
Figure 7-8 Cruise chart, 8 TOW, sea level to 6000 feet. +15°C (Sheet 19 of 24)
Change 9
7-40
TM 55-1520-234-10
Figure 7-8 Cruise chart. 8 TOW, 8000 feet to 14,000 feet. +15°C (Sheet 20 of 24)
Change 9
7-41
TM 55-1520-234-10
Figure 7-8 Cruise chart. 8 TOW. sea level to 6000 feet, +30°C (Sheet 21 of 24)
Change 9
7-42
TM 55-1520-234-10
Figure 7-8 Cruise chart, 8 TOW, 8000 feet to 14,000 feet, +30oC (Sheet 22 of 24)
7-43
TM 55-1520-234-10
o
Figure 7-8 Cruise chart, 8 TOW, 8000 feet to 14,000 feet, +30 C (Sheet 23 of 24)
7-44
TM 55-1520-234-10
o
Figure 7-8 Cruise chart, 8 TOW, 8000 feet-to 12,000 feet, +45 C (Sheet 24 of 24)
7-45
TM 55-1520-234-10
Section VIII. DRAG
The drag chart (figure 7-9, sheet 2 of 2) shows the
additional torque change required for flight due to drag
area change as a result of external configuration
changes. Note that figure 7-9, sheet 1 of 2, presents the
drag increments of many approved armament
configurations.
necessary to know the drag area change, the true
airspeed, the pressure altitude and the free air
temperature. Enter at the known drag area change,
move right to TAS, move down to pressure altitude,
move left to FAT, then move down and read change in
torque. In addition, by entering the chart in the opposite
direction, drag area change may be found from a known
torque change.
7-31. Use of Chart.
7-32. Conditions.
The primary use of the chart is illustrated by the
example. To determine the change in torque it is
The drag chart is based on 324 rotor/6600 engine rpm.
7-30. Description.
Section IX. CLIMB -DESCENT AND LANDING
7-33. Description - Climb-Descent Chart.
b. By entering the bottom of the upper grid with a
known torque change, moving upward to the gross
weight, and left to the corresponding rate of climb or
descent may also be obtained.
The upper grid of the climb-descent chart (figure 7-10)
shows the change in torque (above or below torque
required for level flight under the same gross weight and
atmospheric conditions) to obtain a given rate of climb
or descent. The lower grid of the chart shows the
relationships between descent-climb angles, airspeeds,
and rates of descent or climb.
c. By entering the lower grid chart with any two of
the three parameters (rate of climb/descent, descent
climb angle, or airspeed) the third parameter can be
read directly from the chart. For example, by entering
the chart with a known TAS of 65 knots moving upward
to a known climb angle of nine degrees, and then
moving left, the corresponding rate of climb (1025 feet
per minute) is obtained.
7-34. Use of Climb-Descent Chart.
The primary uses of the chart are illustrated by the
chart examples.
7-35. Conditions.
a. The torque change obtained from the upper grid
scale must be added to the torque required for level
flight (for climb) - or subtracted from the torque required
for level flight (for descent) obtained from the
appropriate cruise chart in order to obtain a total climb
or descent torque.
The climb-descent chart is based on the use of 324
rotor/6600 engine rpm.
7-46
TM 55-1520-234-10
Section X. IDLE FUEL FLOW
7-36. Description.
The idle fuel flow chart (figure 7-11) shows the fuel
flow at engine idle and at flat pitch with : 324 rotor RPN.
7-37. Use of Chart.
The primary use of the chart is illustrated by the
example. To determine the idle fuel flow, it is necessary
to know the idle condition, pressure altitude,
and free air temperature. Enter at the pressure altitude,
move right to FAT in appropriate grid, then move down
and read fuel flow on the scale corresponding to the
(condition. Refer to the cruise charts to obtain fuel flow
for cruise power conditions.
7-38. Conditions.
This chart is based on the use of JP-4 fuel and 324
rotor/6600 engine rpm.
Section XI. AIRSPEED CALIBRATION
7-39. Description.
The airspeed calibration chart (figure 7-12 shows
the difference between indicated and calibrated
airspeeds.
necessary to know the indicated airspeed. Enter the
chart at the indicated airspeed for the applicable
performance condition, move right to the curve, then
down and read calibrated airspeed. In addition. by
entering the chart in the opposite direction, calibrated
airspeed may be converted to indicated airspeed.
7-40. Use of Chart.
The primary use of the chart is illustrated by the
example. To determine calibrated airspeed, it is
Change 2
7-47
TM 55-1520-234-10
Figure 7-9. Drag (Authorized armament configurations) chart (Sheet 1 of 3)
Change 2
7-48
TM 55-1520-234-1
Figure 7-9. Drag (Authorized armament configurations) chart (Sheet 2 of 3)
Change 2
7-48A/(7-48B blank)
TM 55-1520-234-10
Figure 7-9. Drag chart (Sheet 3 of 3)
Change 2
7-49
TM 55-1520-234-10
Figure 7-10. Climb -- descent chart
Change 30
7-50
TM 55-1520-234-10
Figure 7-11. Idle fuel flow chart
7-51
TM 55-1520-234-10
Figure 7-12. Airspeed calibration chart
7-52
TM 55-1520-234-10
CHAPTER 8
NORMAL PROCEDURES
Section I. MISSION PLANNING
8-1. MISSION PLANNING.
Mission planning begins w hen the mission is
assigned and extends to the preflight check of the
helicopter. It includes, but is not limited to, check of
operating limits and restrictions; weight/balance and
loading; performance; publications; flight plan and crew
briefings.
The pilot in command shall ensure
compliance with the contents of this manual that are
applicable to the mission.
necessary to complete the mission in the most efficient
manner. A review of visual signals is desirable when
ground guides do not have a direct voice
communications link with the crew.
8-5. PASSENGER BRIEFING.
The following is a guide that should be used in
accomplishing required passenger briefings. Items that
do not pertain to a specific mission may be omitted.
8-2. AVIATION LIFE SUPPORT EQUIPMENT (ALSE).
a. Crew introduction.
All aviation life support equipment required for
mission; e.g. helmets, gloves, survival vests, survival
kits, etc, shall be checked.
b. Equipment
(1) Personal to include ID tags.
8-3. CREW DUTIES/RESPONSIBILITIES.
(2) Professional.
The minimum crew required to fly the helicopter is a
pilot. Additional crewmembers, as required, may be
added at the discretion of the commander. The manner
in which each crewmember performs his related duties
is the responsibility of the pilot in command.
(3) Survival.
c. Flight Data.
(1) Route.
a. Pilot. The pilot in command is responsible for
all aspects of mission planning, preflight, and operation
of the helicopter. He will assign duties and functions to
all other crewmembers as required. Prior to or during
preflight, the pilot will brief the crew on the mission,
performance
data,
monitoring
of
instruments,
communications, emergency procedures, and armament
procedures.
b. Copilot (when assigned). The copilot must be
familiar with the pilot’s duties and the duties of the other
crew positions. The copilot will assist the pilot as
directed.
c. Crew Chief (when assigned). The crew chief
will perform all duties as assigned by the pilot.
(2) Altitude.
(3) Time en route.
(4) Weather.
d. Normal Procedures.
(1) Entry and exit of helicopter.
(2) Seating.
(3) Seat belts.
(4) Movement in helicopter.
(5) Internal communications.
8-4. CREW BRIEFING.
(6) Security of equipment.
A crew briefing shall be conducted to ensure a
thorough understanding of individual and team
responsibilities. The briefing should include, but not, be
limited to, copilot, mission equipment operator, and
ground crew responsibilities and the coordination
Change 19
(7) Smoking.
(8) Oxygen.
8-1
TM 55-1520-234-10
(9) Refueling.
e. Emergency Procedures.
(10) Weapons.
(1) Emergency exits.
(11) Protective masks.
(2) Emergency equipment.
(12) Parachutes.
(3) Emergency landing/ditching procedures.
(13) Ear protection.
8-6. DANGER AREAS.
(14) ALSE.
Refer to Figure 8-1.
Figure 8-1. Danger areas.
Change 30
8-2
TM 55-1520-234-10
Section II. OPERATING PROCEDURES AND MANEUVERS
8-7. OPERATING PROCEDURES AND MANEUVERS.
This section deals with normal procedures and
includes all steps necessary to ensure safe and efficient
operation of the helicopter from the time a preflight
begins until the flight is completed and the helicopter is
parked and secured. Unique feel, characteristics, and
reaction of the helicopter during various phases of
operation and the techniques and procedures used for
hovering, takeoff, climb, etc., are described, including
precautions to be observed. Your flying experience is
recognized; therefore, basic flight principles are
avoided.
Only the duties of the minimum crew
necessary for the actual operation of the helicopter are
included.
form when a detailed description of a procedure or
maneuver is required. A condensed version of the
amplified checklist, omitting all explanatory text, is
contained in the Operators and Crewmembers
Checklist, TM -1520234-CL.
8-11. PREFLIGHT CHECK.
The pilot's walk-around and interior checks are
outlined in the following procedures. The preflight check
is not intended to be a detailed mechanical inspection.
The steps that are essential for safe helicopter operation
are included.
The preflight may be made as
comprehensive as conditions warrant at the discretion of
the pilot.
8-12. BEFORE EXTERIOR CHECKS.
8-8. MISSION EQUIPMENT CHECKS.
Mission equipment checks are contained in Chapter
4, MISSION EQUIPMENT. Descriptions of functions,
operations, and effects of controls are covered in
Section IV, FLIGHT CHARACTERISTICS, and are
repeated in this section only when required for
emphasis. Checks that must be performed under
adverse environmental conditions, such as desert and
cold weather operations, supplement normal procedures
checks in this section and are covered in Section V,
ADVERSE ENVIRONMENTAL CONDITIONS.
WARNING
Do not preflight
systems are safe.
until
armament
*1. Armament systems— Check as follows:
a. Wing ejector racks - Jettison safety pins
installed.
b. TOW launcher - Missile arming lever up.
8-9. SYMBOLS DEFINITION.
The checklist includes items with annotative
indicators immediately preceding the check to which
they are pertinent; 0 to indicate a requirement if the
equipment is installed. The symbol * indicates that a
detailed procedure for the step is located in the
performance section of the condensed checklist. When
a helicopter is flown on a mission requiring intermediate
stops, it is not necessary to perform all of the normal
checks. The steps that are essential for safe helicopter
operations on intermediate stops are designated as
"thru-flight" checks.
An asterisk indicates that
performance of steps is mandatory for all "thru-flights"
when there has been no change in pilot-in-command.
The asterisk applies only to checks performed prior to
takeoff.
8-10. CHECKLIST.
Normal procedures are given primarily in checklist
form and amplified as necessary in accompanying
paragraph
Change 21
c. Rocket launcher - Igniter arms in contact
with rockets.
d. MASTER ARM switch - OFF.
(O)
e. SMOKE switches - OFF.
f. PLT OVRD switch - OFF.
g. WG ST ARM switch - OFF.
h. TURRET Weapons - SAFE.
*2. Canopy removal arming/firing mechanism
safety pins-IN.
*3. Publications-Check in accordance with DA PAM
738-751 and any locally required forms and
publications.
4. BAT switch-ON.
A minimum of 22 volts
indicates satisfactory condition to attempt battery start.
5. NON-ESS BUS switch-MANUAL.
8-3
TM 55-1520-234-10
6. Lights— Check if use is anticipated.
7. BAT switch— OFF.
*11. Canopy— Check.
8. Pilot's HSS linkage assembly— Check condition
and stow.
9. Area behind pilot seat— Check as follows:
a. First aid kit.
b. Sensor amplifier unit.
c. HSS interface assembly.
(O)
d. Pylon compensator unit.
10. Map light— OFF.
8-13. EXTERIOR CHECK (figure 8-2).
8-14. AREA 1.
*1. Fuel-Check quantity and condition of grounding
receptacle. Secure cap.
*2. Fuel sample-Check for contamination before
first flight of the day. If the fuel sumps and filter have
not been drained, drain and check as follows:
Figure 8-2. Exterior check diagram.
Change 19
8-4
TM 55-1520-234-10
*14. Pylon access - Check condition and security of
FM antenna and engine oil reservoir. Check oil level by
removing cap; then secure cap.
Change 14
15. Swashplate and support - Check condition and
security of collective levers, antidrive link, swashplate
drive links, scissors levers, and friction collet.
84A/(8-4B blank)
TM 55-1520-234-10
a. Sump - Drain.
*12. Transmission area - Check hydraulic pumps,
lines, servo, transmission oil level, filter button
in and main drive shaft.
b. BAT switch - ON.
c. FUEL switch - FUEL.
d. Filter - Drain.
*13. Pylon access - Check engine oil reservoir, oil
level, and electrical connectors.
e. FUEL switch - OFF.
*14. Swashplate and support - Check.
f. BAT switch - OFF.
*15. Main rotor system - Check as follows:
a. Root end fitting inboard surface - Check.
*3. Main rotor blade - Check.
b. Hub moment spring system - Check.
4. Fuselage - Check as follows:
a. Window channel assembly - Check.
(O)
b. Window deflectors
assembly - Check.
and
upper
cutter
*16. Plenum and particle separator - Check for FOD
and check area beneath plenum.
17. Engine compartment - Check air intake,
condition of fuel and oil lines, and fire detector
sensing elements.
c. Static port - Check.
*5. Ammunition bay (right side - Check condition of
door,
loading
security,
and
electrical
wiring/connections. Check hydraulic lines and
follow if installed:
18. Fuselage - Check.
8-15. AREA 2.
1. Tailpipe - Check.
(O)
a. Ammunition drum - Check.
(O)
b. Flexible shaft - Check.
(O)
c. Ammunition chute - Check.
2. Electrical compartment - Check battery, vents,
tailboom attaching bolts for slippage marks and
circuit breakers in.
3. Right side tailboom - Check as follows:
*6. Hydraulic compartment - Check condition of
lines, reservoir, cap, and ECU. Check electrical
connectors and filter buttons in.
a. Air ejector area - Check.
b. Skin - Check.
7. Landing gear - Check.
c. Synchronized elevator - Check.
8. Area beneath transmission— Check condition of
lines, controls, and electrical connectors. Check
accumulator for proper charge.
d. Antennas - Check.
9. Wing - Check.
f. Tail skid - Check.
10. Armament - Check as follows:
(O)
a. TOW - Check.
(O)
b. Rocket launcher - Check.
(O)
c. Wing gun pod - Check.
e. Position light - Check.
*4. 42 degree gearbox - Check oil level, and cap
secure.
*5. Main rotor blade - Check.
*6. Tail rotor - Check.
8-16. AREA 3.
11. Engine and transmission cowling— Secure open.
*1. 90-degree gearbox-Check oil level, and cap
secure.
Change 30
8-5
TM 55-1520-234-10
2.
b. Rocket launcher-Check.
Left side tailboom-Check as follows:
c. Wing gun pod-Check.
a. Position light - Check.
12. Area beneath transmission - Check controls and
condition of hydraulic, oil, and fuel lines.
b. Tail rotor drive shaft - Check.
c. Skin - Check.
13. Landing gear— Check as follows:
d. Antennas - Check.
a. Skids and crosstubes - Check.
e. Synchronized elevator - Check.
b. Skid landing light - Check.
f. Air ejector area - Check.
14. Lower fuselage - as follows:
3. Oil cooler compartment - Check.
a. Searchlight - Check.
8-17. AREA 4.
(O)
b. Lower cutter assembly - Check.
1. Engine and transmission cowling-Secured open.
Check engine air intake, condition of fuel and oil lines,
fire detector sensing elements, and electrical
connectors.
* 15. Hydraulic compartment - Check condition of
lines, reservoir cap, electrical connectors, and ECU.
Check fluid levels and filter buttons in.
*2. Plenem and particle separator-Check for FOD
and area beneath plenum.
16. Canopy-Check. (If single pilot-Perform checks
in paragraph 8-20.)
3. Tail rotor driveshaft - Check.
17. Fire extinguisher - Check.
4. Transmission area-Check lines, servo, and lift
18. Fuselage - Check.
link.
19. Static port - Check.
5. Pylon access - Check engine oil reservoir and
FM antenna.
(O)
6. Swashplate and support - Check.
*20. Ammunition bay (left side) - Check condition of
door, electrical connection, hydraulic lines, and LCHR
boresight switch-OFF. Check following if installed:
7. Top pylon area - Check as follows:
(O)
a. Ammunition drum - Check.
a. Anti-collision light - Check.
(O)
b. Ammunition chute - Check.
b. Pitot tube - Check.
(O)
c. Electrical cables/connectors - Check.
c. Upper cutter assembly - Check.
8-18. AREA 5.
8. Main rotor system - Check.
1. Turret - Check. Refer to Chap 4.
9. Engine and transmission cowlings - Closed.
2. Windshield and rain removal nozzles - Check.
(O) 3. Lower cutter assembly, chin cutter assembly
and nose deflector-Check.
10. Wing - Check.
(O)11. Armament - Check as follows:
*8.19. WALK-AROUND CHECK.
a. TOW - Check.
1. Cowling, doors, and panels-Secure.
2. Covers, tiedown, and grounding cables Removed and secured. Rotate main rotor 90 degrees.
Change 19
8-6
TM 55-1520-234-10
10. Map light-OFF.
(O) 3. Wing store safety pins - Remove.
(O) 4. TOW launcher missile arming lever - Check
down.
a. Crew or passenger briefing - Complete.
8-20. BEFORE STARTING ENGINE-GUNNER
STATION.
*11. Canopy removal arming/firing
safety pin-Remove and stow (if occupied).
mechanism
8-21. BEFORE STARTING ENGINE-PILOT STATION.
*1. IGNITION SW - ON.
*2. Collective friction and lock - OFF.
*3. AC circuit breakers - As required.
*1. Cockpit - General.
a. Seat belt and shoulder harness - Secure.
4. PWR panel switches - Set as follows:
*a. BAT switch - ON.
b. Loose equipment - Secure.
b. GEN switch - OFF.
2. HSS - Check and stow.
c. INV switch - OFF.
*3. Miscellaneous control panel switches - Set as
follows:
d. NON ESS BUS switch - As desired.
a. ELEC PWR switch - ELEC PWR.
* e. MISC PRESS TEST switch - Press.
b. ENG DE-ICE switch - OFF.
5. ENGINE panel switches - Set as follows:
c. GOV switch - AUTO.
a. DEICE switch - OFF.
*4. EMER COLL HYD switch - OFF.
*5. WING STORES JETTISON switch - OFF and
lockwired.
6. Avionics - As required.
*7. System/flight instruments - Check condition,
security, and static indications.
b. FORCE TRIM switch - TRIM.
c. HYD TEST switch - Centered (Both
systems on).
*d. FUEL switch - ON.
lights out.
e. ENG OIL BYP switch - AUTO.
8. Standby compass - Full of fluid and deviation
card current.
* 9. Armament switches - Set as follows:
Check boost pump
f. GOV switch - AUTO.
6. FAT gauge - Check condition.
a. Gunner SHC ACO/TRK/STOW switch STOW.
b. Gunner TCP MODE SELECT switch OFF; system status annunciator displays OFF.
c. Gunner TCP CAMERA switch - OFF.
d. Gunner TCP TSU RTCL switch - OFF.
e. Gunner TCP MISSILE SELECT switch as desired.
f. Gunner AMMO RSV PERCENT dials Set.
7. SCAS POWER switch - OFF.
8. System instruments - Check condition, range
markings, and static indications.
9. Collective accumulator switch - OFF.
10. WING STORES JETTISON switch - Cover
down and lockwired.
11. Compass switch - MAG.
12. Clock - Set.
13. Flight instrument - Check and set as required.
g. TURRET DEPR LIMIT switch - DEPR
LIMIT.
*14. Altimeter - Set.
15. M73 sight - Check.
Change 21
8-7
TM 55-1520-234- 10
4. Throttle - Check and set for start.
16. Armament switches - Set.
5. Engine - Start as follows:
a. WPNS CONTR - Gunner.
a. Start switch - Press and hold (start time).
b. RKT PR SEL switch - As desired.
b. Main rotor - Check turning as N1 reaches
15 percent. If not, abort the start.
c. Smoke grenade dispenser - Set.
d. PSI - Check.
c. Start switch - Release at 40 percent N1 or
after 35 seconds, whichever occurs first.
17. CODE HOLD switch - OFF.
d. IGN SYS circuit breaker - OUT, at 750
degrees C TGT.
*18. FIRE DETECTOR TEST switch - TEST.
19. PITOT HEAT switch - OFF.
e. GEN switch - ON, at 60 percent N1.
20. RAIN REMOVAL/ENVR CONT switch - OFF.
21. HEAT or VENT AIR pull knob - Out and vents
adjust.
*21.1. LOW G warning light - Press to test.
*22. MASTER CAUTION and RPM warning lights Check illuminated.
*23. Caution panel lights - TEST and RESET
MASTER CAUTION light.
g. Throttle - Slowly advance past the engine
idle stop to engine idle position.
Check stop by
attempting to roll throttle off.
h. N1 - Check 68 percent to 72 percent.
Hold a slight pressure against the idle stop during this
check.
i. IGN SYS circuit breaker - IN after TGT
has stabilized.
24. Avionics - OFF; set as desired.
25. Light switched - Set as required.
6. GPU-Disconnect after GPU start.
*26. DC circuit breakers - In except TOW BLOW.
*27. Canopy removal arming/firing
safety pin - Remove and stow.
f. INV switch - STBY for first flight of day
and MAIN for thru-flight.
mechanism
7. BAT switch - ON.
8. Systems - Check as follows:
a. Engine and transmission oil pressures -
*8.22. STARTING ENGINE
Check.
b. Caution lights - Check off.
WARNING
c. Ammeter - Check less than 200 amps.
When helicopter is armed with rockets, make start with
battery only, because it is hazardous to place GPU (or
any electrical generating equipment) in close proximity
due to danger of accidental firing of rockets.
1. GPU-Connect if GPU starting.
OFF.
CAUTION
Oil pressure may exceed maximum
on low ambient temperature starts.
Do not exceed engine idle until
engine oil pressure is below 100 psi.
(BAT switch-
2. Fireguard - Posted, if available.
3. Rotor
blades
-
Check
clear
and
untied.
Change 30
8-8
TM 55-1520-234-10
f. DEICE switch - Check as required.
8-23. ENGINE RUNUP.
CAUTION
g. Pilot heater - Check as required.
Minimize movement of the cyclic during ground runup to
preclude damage to the input quill seal and the main
driveshaft.
*8 SCAS-Check as follows:
a. NO-GO lights - Check out.
*1. Avionics/mission equipment - On as desired.
NOTE
*2. SCAS POWER switch - POWER check NO-GO
lights illuminate, and remain on for approximately 10
seconds, then extinguish prior to 30 seconds).
If the mechanically dimmable NO-GO lights are
dimmed, a false indication could result in engagement
of SCAS with an out-of-null condition.
3. Hydraulic system - Check as follows:
a. FORCE TRIM switch - OFF.
b. HYD TEST switch - SYS 1 (system 2 out);
MASTER CAUTION and #2 HYD PRESS caution lights
should illuminate; all controls should be free.
c. HYD TEST switch - SYS 2 (system 1 out),
MASTER CAUTION and #1 HYD PRESS caution lights
should illuminate, pedals will be stiff but movable, cyclic
and collective free.
d. HYD TEST switch - Center position, #1
and #2 HYD PRESS caution lights should be out.
e. FORCE TRIM switch - FORCE TRIM.
b. Engage PITCH, ROLL, and YAW
channels one at a time and visually check around the
helicopter. Have hand on the cyclic stick, and be
prepared to immediately press the SAS REL switch if
any abnormal tip path or control fluctuations are noted.
c. Press the SAS REL switch on gunner's
cyclic and pilot checks channels are OFF.
d. Pilot checks NO-GO lights are out and
reengages PITCH, ROLL, and YAW channels; then,
press the SAS REL switch on his cyclic. Check
channels are OFF.
e. Pilot checks NO-GO lights are out and
reengages PITCH, ROLL, and YAW channels.
*9. Armament system - Set as follows:
*4. Canopy door - Secure.
a. MASTER ARM - STBY.
*5. Throttle - 6600. As throttle is increased, the low
rpm audio and light should be off at 6200 ± 100 rpm.
Throttle friction as desired.
6. Deleted.
b. TCP switch - STBY TOW.
c. TOW BLOW circuit breaker - IN.
*10. Avionics/mission equipment - Check and set as
required.
*7. Systems - Check as follows:
a. Fuel quality - Check and depress FUEL
GAGE TEST switch.
b. Engine instruments - Check.
c. Transmission instruments - Check.
*11. Altimeter - Check and set as required.
*12. RMI - Corresponds with standby compass. Set
as required.
*13. Attitude indicator - Set.
d. DC voltmeter - Check for approximately
27.5 volts.
*14. Armament systems - Check as follows:
a. HSS built-in-test - Check.
e. INV switch - MAIN (INST INSERTER light
out).
Change 30
8-9
TM 55-1520-234- 1 0
b. HSS to turret - Check.
*8-25. BEFORE TAKEOFF
1. RPM - 660.
c. HSS to TSU - Check.
2. Systems - Check engine,
electrical, and fuel systems indications.
d. TSU to turret - Check.
e. TOW built-in-test - Check.
3. Avionics - As required.
f. TSU fast rate tracking - Check.
4. Mission equipment - Set as required.
g. TSU slow rate tracking - Check.
5. Armament switches - Set.
h. TSU motion compensation - Check.
8-26. MAXIMUM PERFORMANCE.
i. M73 sight - ON and check.
15. Health Indicator Test (HIT) check Perform as required on first flight of the day.
* 16. Armament switches - Set as follows:
a. Gunner PLT OVRD switch - OFF.
b. Pilot MASTER ARM switch - STBY.
c. TCP - TSU/GUN.
d. TOW launchers - Missile arming lever
down.
e. Wing ejector rack jettison safety pins Removed.
f. Other switches - Set for mission rqmts.
*8-24. HOVER CHECK.
Perform the following checks at a hover:
1. Flight controls - Check for correct position and
response.
2. Engine and transmission instruments - Check.
3. Flight instruments - Check as required.
a. Airspeed indicator - Check airspeed.
b. Attitude indicator - Indicates nose high or
low and banks left and right.
c. VSI and altimeter - Indicate climb and
descent.
d. Slip indicator - Ball free in race.
e. Turn needle.
RMI,
compass indicate turns left and right.
transmission,
and
magnetic
4. Power-check. The power check is performed by
comparing the indicated torque required to hover with
the predicted values from performance charts.
Change 30
A takeoff that demands maximum performance
from the helicopter is necessary because of various
combinations of heavy helicopter loads, restricted
performance due to high density altitudes, barriers that
must be cleared and other terrain features.
The
decision to use either of the following takeoff techniques
must be based on an evaluation of the conditions and
helicopter performance.
a. Coordinated Climb (maximurn performance).
Align the helicopter with the desired takeoff course at a
stabilized hover of approximately 3 feet (skid height).
Apply forward cyclic smoothly and gradually while
simultaneously increasing collective pitch to begin a
coordinated acceleration and climb. Adjust pedal as
necessary to maintain the desired heading. Maximum
torque available should be applied (without exceeding
helicopter limits) as the helicopter attitude is established
that will permit safe obstacle clearance. The climbout is
continued at that attitude and power setting until the
obstacle is cleared. After the obstacle is cleared, adjust
helicopter attitude and collective pitch as required to
establish a climb at the desired rate and airspeed.
Continuous coordinated application of control pressures
is necessary to maintain trim, heading, flight path,
airspeed, and rate of climb. Takeoff may he made from
the ground by positioning the cyclic control slightly
forward of neutral prior to increasing collective pitch.
b. Level Acceleration. Align the helicopter with
takeoff course at a stabilized hover of approximately 3
feet (skid height). Apply forward cyclic smoothly and
gradually while simultaneously increasing collective
pitch to begin an acceleration at approximately 3 to 5
feet skid height. Adjust pedal to maintain heading.
Maximum torque available should be applied (without
exceeding helicopter limits) prior to accelerating through
effective translational lift. Additional
8-10
TM 55-1520-234-1 0
forward cyclic pressure will be necessary to allow for
level acceleration to the desired climb airspeed.
Approximately 5 knots prior to reaching the desired
climb airspeed, gradually release forward cyclic
pressure and allow the helicopter to begin a constant
airspeed climb to clear the obstacle. Care must be
taken not to decrease airspeed during the climbout since
this may result in the helicopter descending (falling
through). After the obstacle is cleared, adjust helicopter
attitude and collective pitch as required to establish
desired rate of climb and airspeed.
Continuous
coordinated application of control is necessary to
maintain trim, heading, flight path, airspeed, and rate of
climb. Takeoff may be made from the ground by
positioning the cyclic control slightly forward of neutral
prior to increasing collective pitch.
c. The two techniques give approximately the
same distance over a 50-foot obstacle when the
helicopter can just hover OGE. As hover capability is
decreased.
the level acceleration technique gives
increasingly shorter distances than the coordinated
climb technique. Where the two techniques yield the
same distance over a 5 foot obstacle, the coordinated
climb technique will give a shorter distance over lower
obstacles and the level acceleration technique will give
a shorter distance over obstacles higher than 50 feet. In
addition to the distance comparison, the main
advantages of the level acceleration technique are as
follows: (1) It requires less or no time in the avoid area
of the height velocity diagram; (2) performance is more
repeatable; (3) at the higher climbout airspeeds (30
knots or more), reliable indicated airspeeds are
available for accurate airspeed reference from the
beginning of the climbout, therefore minimizing the
possibility of fall-through. The main advantage of the
coordinated climb technique is that the climb angle is
established early in the takeoff and more distance and
time are available to abort the takeoff if the obstacle
cannot be cleared.
8-27. BEFORE LANDING.
2. Transponder - As required.
8-29. ENGINE SHUTDOWN.
1. Throttle - Reduce to idle. Allow TGT to stabilize
for two minutes.
2. FORCE TRIM switch - FORCE TRIM.
3. Armament systems - OFF and set as follows:
a. TOW BLOW circuit breaker - OUT.
b. TCP switch - OFF.
c. MASTER ARM switch - OFF.
d. HSS linkage - TOW.
e. TURRET DEPR LIMIT switch - DEPR
LIMIT.
f. M73 sight - OFF.
4. Systems - Check and turn off as follows:
a. DEICE switch - OFF.
b. SCAS POWER switch - OFF.
c. ECU panel switches - OFF.
d. Engine, transmission,
indications - Check indications.
and
electrical
e. Avionics and mission equipment - OFF.
f. Lights - Set as required.
5. Throttle-OFF.
6. ENGINE and PWR panel switches-Set as
follows:
a. FUEL switch - OFF.
b. INV switch - OFF
c. GEN switch - OFF.
7. Collective accumulator - Check as follows:
1. GUNNER PLT OVRD switch - OFF.
a. EMER COLL HYD switch - OFF. Attempt
to raise collective. If collective cannot be raised, the
accumulator is functioning properly.
2. MASTER ARM switch - STBY.
3. TCP - TSU/GUN.
b. EMER COLL HYD switch - ON. Move
collective full up and down one stroke, then OFF.
4. Searchlight - As required.
8-28. AFTER LANDING.
1. Searchlight - As required.
Change 30
8-11
TM 55-1520-234-10
c. Gunner EMER COLL HYD switch-ON.
Move collective full up and down one stroke. This
indicates that the gunner's EMER COLL HYD switch is
working properly. Continue to bleed the accumulator
with short strokes from the down position to prevent the
collective from stopping in the up position. If collective
stops in up position, rotate the main rotor in the normal
direction of rotation and simultaneously move the
collective to the down position.
d. Gunner's EMER COLL HYD switch - OFF.
1. Post flight - Check for damage, fluid leaks and
levels.
2. Mission equipment - Secure.
3. All armament - Check as follows:
a. Wing ejector rack jettison safety pins Installed.
b. TOW missile arming lever - Up (if
missiles are installed).
Remove key as
c. Rocker igniter arms-In contact with
rockets to reduce possibility of ignition from
electromagnetic interference (EMI).
10. Both canopy removal arming/firing mechanism
safety pins-In.
4. Complete all forms and records. An entry on
DA Form 2408-13 is required if any of the following
conditions were experienced:
8. BAT switch - OFF.
9. IGNITION switch - OFF.
required.
a. Flown in a loose grass environment.
8-30. BEFORE LEAVING HELICOPTER.
b. Operated within 10 nautical miles of salt
WARNING
water.
When helicopter is to be parked
where ambient temperature equals or
exceeds 32 degrees C, the fire
extinguisher shall be removed until
the next mission.
c. Operated within 200 nautical miles of
volcanic activity.
d. Exposed to radioactivity.
5. Secure helicopter.
Section III. INSTRUMENT FLIGHT
8-31. INSTRUMENT FLIGHT PROCEDURES.
This helicopter is not qualified for operation under
instrument meteorological conditions although adequate
navigation and communications equipment are installed
for instrument flight. Flight characteristics and range
Change 21
are the same during instrument flight conditions as
operations in visual flight conditions. Refer to FM 1240, FM 1-300, AR 95-1, and FAR Part 91 for
instrument flight rules and weather information.
8-12
TM 55-1520-234-10
Section IV. FLIGHT CHARACTERISTICS
8-32. OPERATING CHARACTERISTICS.
The flight characteristics of this helicopter, in
general, are similar to other single rotor helicopters
8-33.. ROLLOVER CHARACTERISTICS.
Refer to FM 1-203, Fundamentals of Flight.
8-34. BLADE STALL.
a. General. In forward flight, some portions of the
rotor disk swept by the retreating blade are always
stalled. How this stalled area affects the performance
and flying qualities depends on the size of the stalled
area. The size of the stalled area increases with
increase in gross weight, airspeed, density altitude, "g"
loading, or with a decrease in rpm. The rolling and
pitching motion which is often associated with rotor stall
will not occur.
Change 21
b. Stall Recognition.
The pilot will notice a
progressive increase in vertical vibration level, mostly at
2 per rev, as more of the rotor disk becomes stalled. An
increase in any of the above stall-inducing factors will
result in higher 2 per rev vibration and eventually the
onset of control force feedback. Both the 2 per rev
vibration and feedback forces will be progressively
greater as blade stall affects more of the rotor area.
Because of the progressive nature of blade stall with this
rotor system, there is no abrupt threshold or onset of
rotor stall and therefore no meaningful "stall limit" exists.
c. Stall Reduction.
(1) The amount of stall and associated
vibration encountered may be reduced by reducing
collective.
(2) Reducing the g loading of the maneuver
may be accomplished by applying:
8-12A/8-12B
TM 55-1520-234-10
8-36. DIVING FLIGHT.
(a) Forward cyclic.
(b) Reducing airspeed.
WARNING
If an abrupt recovery is attempted at
speeds near VNE, "mushing" of the
helicopter can occur. If mushing is
experienced,
do
not
increase
collective, as this will aggravate the
condition. Figure 8-3 depicts the
altitude lost during a pullout versus
rate of descent for various g
loadings.
(c) Increasing operating rpm.
(d) Reducing altitude.
8-35 CONTROL FEEDBACK.
a. Feedback in the cyclic stick or collective stick is
caused by high loads in the control system. These loads
are generated during severe maneuvers and can be of
sufficient magnitude to overpower or feed through the
main boost cylinders and into the cyclic and/or collective
stick. The pilot will feel this feedback as an oscillatory
"shaking" of the controls even though he may not be
making control inputs after the maneuver is established.
This type of feedback will normally vary with the severity
of the maneuver. The pilot should regard it as a cue
that high control system loads are occurring and should
immediately reduce the severity of the maneuver.
b. The gunner station side arm flight controls are
designed for emergency conditions and have a reduced
mechanical advantage.
Because of this reduced
mechanical advantage of the gunner's cyclic and
collective control, severe maneuvers should be avoided
while flying from the gunner station.
Diving flight presents no particular problems in the
helicopter; however, the pilot should have a good
understanding of such things as rates of descent versus
airspeed, rate of closure, and rates of descent versus
power. The helicopter gains airspeed quite rapidly in a
dive and it is fairly easy to exceed VNE. Rates of
descent of 3500 ft./min. to 4800 ft./min. are not
uncommon during high-speed dives. High rates of
descent coupled with high
Figure 8-3. Dive recovery distances
Change 19 8-13
TM 55-1520-234-10
flight path speeds require that the pilot monitor both rate
of closure and terrain features very closely and plan his
dive recovery in time to avoid having to make an abrupt
recovery.
8-37. POWER DIVES.
At speeds above the maximum level flight speed,
the rate of descent will increase approximately 1000
ft./min. for every 10 knots increase in airspeed for the
full power condition.
8-38. PITCH CONE COUPLING.
a. Pitch cone coupling is the characteristic of the
rotor to inherently reduce blade pitch with increasing
coning under loading which aids to maintain rpm and
retard blade stall. With severe rotor loading, the rotor
rpm may overspeed above the red line unless collective
pitch is increased.
b. When g load is placed upon the rotor system
through steep turns, dive recoveries, or other high-stress
maneuvers, the rotor blades cone upward. Most of the
inherent bending action is absorbed by the flexible yoke
assembly. As the hub bends, the pitch change horns
exert a downward pressure on the pitch control tubes.
The control tubes, however, are fixed through the
control system and are unable to move. As pressure
continues to be applied, the leading edge of the blade
begins to rotate downward via the feather bearing. This
directly reduces pitch in the blades which in turn acts to
increase rotor rpm. As the rotor rpm begins to increase,
the N2 governor senses the change and begins to
decrease engine power, resulting in a corresponding
decrease in torque and N1.
When performing g
maneuvers, maintaining a constant torque setting is of
prime importance in preventing over-speeding of the
rotor.
8-39. TRANSIENT TORQUE.
a. Transient torque, although evident in all semirigid single-rotor system helicopters, is a phenomenon
which is quite pronounced in the AH-1S. With a rapid
application of left lateral cyclic, a rapid torque increase
followed by a decrease will be evidenced.
This
condition occurs as a result of temporary increased
induced drag being placed on the rotor system by the
additional pitch in the advancing blade.
b. With a rapid application of right lateral cyclic, a
rapid torque decrease followed by an increase will be
evidenced. This condition occurs as a result of drag
being reduced in the rotor system due to the reducing of
pitch in the advancing blade, which temporarily
decreases the blade's resistance to the airflow.
Increasing and decreasing rotor system drag will
produce corresponding torque changes due to the fact
that the rotor system requirement for an increase or
decrease in power is sensed and subsequently supplied
by the fuel control system. As airspeed and severity of
the maneuver are increased, the transient torque effect
is also increased. The pilot should become familiar with
this characteristic and form a natural tendency to
compensate with collective control to avoid exceeding
the helicopter torque and rotor rpm limitations.
8-40. MANEUVERING FLIGHT.
During left rolling maneuvers or high -power dives,
torque increases occur. To prevent main transmission
overtorque, care must be exercised in monitoring torque
pressure to enable the pilot to reduce power as required
to prevent overtorque.
8-41. LOW G MANEUVERS.
WARNING
Intentional flight below +0.5 "g's" is
prohibited.
Abrupt inputs of the flight controls
cause excessive main rotor flapping,
which may result in mast bumping
and must be avoided.
If an abrupt right roll should occur
when rapidly lowering the nose,
PULL IN AFT CYCLIC to stop the rate
and effect recovery.
Left lateral
cyclic WILL NOT effect recovery from
a well-developed right roll during
flight at less than one g, and it may
cause severe main rotor flapping.
DO
NOT
move
collective
or
directional controls or disengage the
SCAS during recovery.
a. Because of mission requirements, it may be
necessary to rapidly lower the nose of the helicopter in
order to (1) acquire a target; (2) stay on target; or (3)
recover from a pullup. At moderate to high airspeeds, it
becomes increasingly easy to approach zero or negative
load factors by abrupt forward cyclic inputs. The
helicopter may exhibit a tendency to roll to the right
simultaneously with the forward cyclic input; this
characteristic being most pronounced when roll SCAS is
disengaged.
b. Such things as sideslip, weight and location of
wing stores and airspeed will affect the severity of the
right roll. Variances in gross weight, longitudinal cg, and
rotor rpm may affect the roll characteristics. The right
roll occurs throughout the normal operating airspeed
Change19 8-14
TM 55-1520-234-10
range and becomes more violent at progressively lower
load factors.
movement will produce a rotor rpm other than that
produced under steady-state conditions as follows:
(1) From low airspeed. Example: From a
stabilized 30-knot autorotative condition, a positive
forward cyclic movement to increase airspeed will cause
the rotor rpm to decrease initially and then increase
when the helicopter is stabilized at the higher speed.
NOTE
When it is necessary to rapidly lower
the nose of the helicopter, it is
essential that the pilot monitor
changes in roll attitude as the cyclic
is moved forward.
(2) From high airspeed. Example: From a
stabilized 120 KIAS autorotative condition, a positive aft
cyclic movement to decrease airspeed will cause the
rotor rpm to increase initially and then decrease when
the helicopter is stabilized at the lower speed.
8-42. SETTLING WITH POWER.
Refer to FM 1-203, Fundamentals of Flight.
8-43. ROTOR RPM-POWER OFF.
The following steps list the factors which affect
power-off rotor rpm.
a. Air speed. In autorotation, rotor rpm varies with
airspeed. Maximum rotor rpm is achieved at a steady
state of 60 to 80 knots (figure 8-4).
Rotor rpm
decreases at stabilized airspeeds above or below 60- to
80-knot range.
When changing airspeeds, cyclic
b. Gross Weight. The power-off rotor rpm varies
significantly with gross weight. A low gross weight will
produce a low rotor rpm. A high gross weight will
produce a high rotor rpm. With the collective system
correctly rigged to a minimum blade angle (full down
collective stick), the pilot must manually control rpm
with the collective stick in order to prevent overspeed of
the rotor when at high gross weight.
Figure 8-4. Main rotor rpm versus airspeed
Change 19 8-15
TM 55-1520-234-10
8-44. AUTOROTATION CHARACTERISTICS.
a. Rotor Speed. The K747 main rotor blades have
a greater tendency to overspeed in autorotation than the
B540 main rotor blades.
(3) If mast bumping occurs during rearward
or sideward flight, move cyclic slightly toward center
position and apply pedal to bring the nose into the
relative wind.
b. Refer to FM 1-230, Fundamentals of Flight,
Section IV, Autorotation.
b. Because of mission requirements, it may be
necessary to rapidly lower the nose of the helicopter
with cyclic input or make a rapid collective reduction. At
moderate to high airspeeds, it becomes increasingly
easy to approach less than +0.5 "g's" by abrupt forward
cyclic inputs. Variance in such things as sideslip,
airspeed, gross weight, density altitude, center of
gravity, and rotor speed may increase main rotor
flapping and increase the probability of mast bumping.
Rotor flapping is a normal part of maneuvering and
excessive flapping can occur at greater than 1 "g" flight;
but, flapping becomes more excessive for many given
maneuvers at progressively lower load factors.
8-45. MAST BUMPING.
WARNING
Abrupt inputs of the flight controls
cause excessive main rotor flapping,
which may result in mast bumping
and must be avoided.
a. Mast bumping (flapping-stop contact) is the
main rotor yoke contacting the mast. It may occur
during slope landings, rotor start-up/coast-down, or
when the approved flight envelope is exceeded. If mast
bumping is encountered in flight, land as soon as
possible.
(1) If mast humping occurs during a slope
landing, reposition the cyclic control to stop the bumping
and reestablish a hover.
(2) If mast bumping occurs during start-up or
shut-down, move cyclic to minimize or eliminate
bumping.
(1) In the event of loss of all engine power at
high speed, aft cyclic must be applied to maintain rotor
rpm and to avoid mast bumping during autorotation
entry.
(2) If the flight envelope is inadvertently
exceeded by low g flight (below +0.5g), move the cyclic
aft to regain positive thrust on the rotor before correcting
rolling tendencies.
Change 19 8-16
TM 55-1520-234-10
Section V. ADVERSE ENVIRONMENTAL CONDITIONS
8-46. GENERAL.
This section provides information relative to
operation under adverse environmental conditions
(snow, ice and rain, turbulent air, extreme cold and hot
weather, desert operations, mountainous and altitude
operation) at maximum gross weight. Section II check
list provides for operational requirement of this section.
use open flame and avoid overheating boot) to thaw the
spherical couplings before attempting to start engine.
8-47. COLD WEATHER OPERATIONS.
Operation of the helicopter in cold weather or an
arctic environment presents no unusual problems if the
operators are aware of those changes that do take place
and conditions that may exist because of the lower
temperatures and freezing moisture.
a. Inspection. The pilot must be more thorough in
the walk-around check when temperatures have been at
or below 0 degrees C (32 degrees F). Water and snow
may have entered many parts during operations or in
periods when the helicopter was parked unsheltered.
This moisture often remains to form ice which will
immobilize moving parts or damage structure by
expansion and will occasionally foul electric circuitry.
Protective covers afford major protection against rain,
freezing rain, sleet, and snow when installed on a dry
helicopter prior to precipitation. Since it is not practical
to completely cover an unsheltered helicopter, those
parts not protected by covers and those adjacent to
cover overlap and joints require closer attention,
especially after a blowing snow or freezing rain.
Accumulation of snow and ice should be removed prior
to flight. Failure to do so can result in hazardous flight,
due to aerodynamic and center of gravity disturbances
as well as the introduction of snow, water, and ice into
internal moving parts and electrical systems. The pilot
should be particularly attentive to the main and tail rotor
systems and their exposed control linkages.
CAUTION
At temperatures of -35 degrees C (-31
degrees F) and lower, the grease in
the spherical couplings of the main
and
tail
rotor
transmission
driveshafts and tail-rotor driveshaft
coupling may congeal to a point that
the
couplings
cannot
operate
properly.
If temperature is -44
degrees C (-47 degrees F) or below
the pilot must be particularly careful
to monitor engine instruments for
high oil pressure.
b. Transmission. Check for proper operation by
turning the main rotor opposite to the direction while an
observer watches the driveshaft to see that there is no
tendency for the transmission to "wobble" while the
driveshaft is turning. If found frozen, apply heat (do not
(2) Exterior check 0 degrees C (32 degrees
F) to -54 degrees C (-65 degrees F). Perform exterior
check as outlined in Section II, plus the following
checks.
c. Checks.
(1) Before exterior check 0 degrees C (32
degrees F) and lower. Perform check as specified in
Section II.
(a) Surfaces and controls-Check free of
ice and snow. Deicing fluid or heat should be used to
remove ice.
(b) Fluid levels-Contraction of the fluids
in the helicopter system at extreme low temperature
causes indication of low levels. A check made just after
the previous shutdown and carried forward to the
walkaround check is satisfactory if no leaks are in
evidence. Filling when the system is cold will reveal an
overfull condition immediately after flight, with the
possibility of forced leaks at seals.
(c) Engine Air Inlet-Remove all loose
snow that could be pulled into and block the engine
intake during starting.
(3) Interior check-All flights 0 degrees C (32
degrees F) to -54 degrees C (-65 degrees F). Perform
check as specified in Section II.
(4) Interior check-Night flights 0 degrees C
(32 degrees F) to - 54 degrees C (-65 degrees F).
Perform check as specified in Section II.
(5) Engine starting check-0 degrees C (32
degrees F) to -54 degrees C (-65 degrees F).
Change 19 8-17
CAUTION
As the engine cools to an ambient
temperature below 0 degrees C (32
degrees F) after engine, shutdown,
condensed moisture may freeze
engine seals. Ducting hot air from
an external source through the air
inlet housing will free a frozen rotor.
Perform check as outlined in Section
11. During cold weather, starting the
engine oil pressure gage will indicate
maximum (100 psi).
The engine
should be warmed up at engine idle
until the engine oil pressure
indication is below 100 psi.
TM 55-1520-234-10
(6) Hydraulic filter indicators-Reset if popped
out.
(7) Engine runup check. Perform the check
as outlined in Section 11.
WARNING
Control system checks should be
performed with extreme caution
when helicopter is parked on snow
and ice.
There is reduction in
ground
friction
holding
the
helicopter stationary, controls are
sensitive and response is immediate.
d. Engine Starting Without External Power Supply.
If a battery start must be attempted when the helicopter
and battery have been at temperatures between -26
degrees C to -37 degrees C (-15 degrees F to -35
degrees F), preheat the engine and battery if equipment
is available and time permits. Preheating will result in a
faster starter cranking speed which tends to reduce hot
start hazard by assisting the engine to reach a selfsustaining speed (40 percent N1) in the least possible
time.
h. The altimeter is unreliable due to differential
barometric pressures within the storm. An indicated
gain or loss of several hundred feet is not uncommon
and should be allowed for in determining minimum safe
altitude.
8-51. ICING CONDITIONS.
WARNING
Intentional flight in known moderate
or greater icing conditions is
prohibited. If icing conditions are
encountered during flight, every
effort should be made to vacate the
icing environment.
WARNING
Firing of aircraft weapons in icing
conditions is prohibited.
The
weapons covered are: TOW missile,
2.75 inch FFAR, 40MM Grenade
Launcher, and 7.62MM MG. A very
serious safety hazard exists if aircraft
weapons are fired in icing weather
conditions.
The TOW missile
warhead can detonate in close
proximity to aircraft. The warhead
fuse is damaged as missile is
launched through ice ill missile
launcher. Gun barrels and breeches
can rupture if gun muzzles are
clogged with ice. The FFAR are held
captive in the launcher tubes by the
frozen ice.
8-48. SNOW.
Refer to FM 1-202, Environmental Flight.
8-49. DESERT AND HOT WEATHER OPERATION.
Refer to FM 1-202, Environmental Flight.
8-50. TURBULENCE AND THUNDERSTORMS.
Flight in thunderstorms and heavy rain which
accompanies thunderstorms should be avoided. If
turbulence and thunderstorms are encountered
inadvertently, use the following procedures:
a. Check that safety belts and harnesses are
tightened.
CAUTION
When operating at FAT of 5°C (40°F)
or below, icing of the engine air
particle separator and FOD screens
can be expected.
Continued
accumulation of ice will result in
partial or complete power loss.
b. PITOT HTR-ON.
c. Power-Adjust to maintain a penetration speed of
100 KIAS or VNE whichever is slower.
d. Radios-Turn volume down
equipment badly affected by static.
on
any
radio
e. At night-Turn interior lights to full bright to
minimize blinding effect of lightning
f. Maintain a level attitude and constant power
setting. Airspeed fluctuations should be expected and
disregarded.
g. Maintain the original heading, turning only when
necessary.
Change 30
Continuous flight in light icing
conditions is not recommended
because the ice shedding induces
rotor blade vibrations, adding greatly
to the pilot's work load.
a. If icing conditions become unavoidable, the pilot
should turn the PITOT HEAT, ENVR CONT and DEICE
switches on.
8-18
TM 55-1520-234-10
b. During icing conditions, one or all of the
following can be expected to occur:
(1) Obscured forward field of view due to ice
accumulation on the canopy. If the ECU fails to keep
the canopy clear of ice, the side windows may be used
for visual reference during landing.
(2) One-per-rotor-revolution
vibrations
ranging from mild to severe caused by asymmetrical ice
shedding from the main rotor system. The severity of
the vibration will depend upon the temperatures and the
amount of ice accumulation on the blades when the ice
shed occurs. The possibility of an asymmetric ice shed
occurring increases as the outside air temperature
decreases. Severe vibrations may occur as a result of
main rotor asymmetrical ice shedding.
If icing
conditions are encountered while in flight, land as soon
as practicable. All ice should be removed from the rotor
system before attempting further flight.
(3) An increase in torque required to maintain
a constant airspeed and altitude due to ice accumulation
on the rotor system.
(4) Possible degradation of the ability to
maintain autorotational rotor speed within operating
limits.
c. Control activity cannot be depended upon to
remove ice from the main rotor system. Vigorous
control movements should not be made in an attempt to
reduce
low-frequency
vibrations
caused
by
asymmetrical shedding of ice from the main rotor
blades.
These movements may induce a more
asymmetrical shedding of ice, further aggravating
helicopter vibration levels.
d. If a 5 psi (or greater) torque pressure increase is
required above the cruise torque setting used prior to
entering icing conditions, it may not be possible to
maintain autorotational rotor speed within operational
limits, should an engine failure occur.
WARNING
Ice shed from the rotor blades and/or
other rotating components presents
a hazard to personnel during landing
and shutdown.
Ground personnel should remain
well clear of the helicopter during
landing
and
shutdown
and
passengers/crewmembers
should
not exit the aircraft until the rotor has
stopped turning.
8-52. RAIN.
WARNING
Rain removal system
remove rain in flight.
Change 19 8-19/(8-20 blank)
does
not
TM 55-1520-234-10
Figure 8-4. Dive recovery distances
8-21
TM 55-1520-234-10
WARNING
If an abrupt right roll should occur
when rapidly lowering the nose,
PULL IN AFT CYCLIC to stop the rate
and effect recovery.
Left lateral
cyclic WILL NOT effect recovery from
a well developed right roll during
flight at less than one "g" and it may
cause severe main rotor flapping.
DO
NOT
move
collective
or
directional controls or disengage the
SCAS during recovery.
8-68. TRANSIENT TORQUE.
a. Transient torque, although evident in all semirigid single rotor system helicopters, is a phenomenon
which is quite pronounced in the AH-IS. With a rapid
application of left lateral cyclic a rapid torque increase
followed by a decrease will be evidenced.
This
condition occurs as a result of temporary increased
induced drag being placed on the rotor system by the
additional pitch in the advancing blade.
b. With a rapid application of right lateral cyclic a
rapid torque decrease followed by an increase will be
evidenced. This condition occurs as a result of drag
being reduced in the rotor system due to the reduction
of pitch in the advancing blade, which temporarily
decreases the blade's resistance to the airflow.
Increasing and decreasing rotor system drag will
produce corresponding torque changes due to the fact
that the rotor system's requirement for an increase or
decrease in power is sensed and subsequently supplied
by the fuel control system. As airspeed and severity of
the maneuver are increased, the transient torque effect
is also increased. The pilot should become familiar with
this characteristic and form a natural tendency to
compensate with collective control to avoid exceeding
the helicopter torque and rotor rpm limitations.
8-69. MANEUVERING FLIGHT.
During left rolling maneuvers or high power dives
torque increases occur. To prevent main transmission
overtorque, care must be exercised in monitoring torque
pressure to enable the pilot to reduce power as required
to prevent overtorque conditions.
Because of mission requirements, it may be
necessary to rapidly lower the nose of the helicopter in
order to (1) acquire a target; (2) stay on target; or (3)
recover from a pullup. At moderate to high airpseeds, it
becomes increasingly easier to approach zero or
negative load factors by abrupt forward cyclic inputs.
The helicopter may exhibit a tendency to roll to the right
simultaneously with the forward cyclic input; this
characteristic being most pronounced when roll SCAS is
disengaged.
Such things as sideslip, weight and location of wing
stores, and airspeed will affect the severity of the right
roll. Variances in gross weight, longitudinal cg, and
rotor rpm may affect the roll characteristics. The right
roll occurs throughout the normal operating airspeed
range and becomes more violent at progressively lower
load factors.
NOTE
When it is necessary to rapidly lower
the nose of the helicopter, it is
essential that the pilot monitor
changes in roll attitude as the cyclic
is moved forward.
8-70. LOW "G" MANEUVERS.
WARNING
Intentional flight below + 0.5 "G's" is
prohibited.
Abrupt inputs of the flight controls
cause excessive main rotor flapping,
which may result in mast bumping
and must be avoided.
8-70A. MAST BUMPING.
WARNING
Abrupt inputs of the flight controls
cause excessive main rotor flapping,
which may result in mast bumping
and must be avoided.
Mast bumping (flapping-stop contact) is the main
rotor yoke contacting the mast. It may occur during
slope landings, rotor start-up/coastdown, or when the
approved flight envelope is exceeded. If mast bumping
is encountered in flight, land as soon as possible.
Change 16 8-22
TM 55-1520-234-10
If bumping occurs during a slope landing, reposition
the cyclic to stop the bumping and reestablish a hover.
If bumping occurs during startup or shutdown, move
cyclic to minimize or eliminate bumping.
Figure 84A represents a matrix of flight maneuvers
which produce high flapping and the flight conditions
which amplify flapping.
For example, because of
mission requirements, it may be necessary to rapidly
lower the nose of the helicopter with cyclic input or
make a rapid collective reduction. At moderate to high
airspeeds it becomes increasingly easy to approach less
than + 0.5 "G's" by abrupt forward cyclic inputs.
Variance in such things as sideslip, airspeed, gross
weight, density altitude, center of gravity, and rotor
speed may increase main rotor flapping and increase
the probability of mast bumping. Rotor flapping is a
normal part of maneuvering and excessive for many
given maneuvers at progressively lower load factors.
If the flight envelope is inadvertently exceeded,
causing a low "G" condition and right roll, move cyclic
aft to return rotor to a positive thrust condition, then roll
level, continuing flight if mast bumping has not
occurred.
As collective pitch is reduced after engine failure or
loss of tail rotor thrust, cyclic must be positioned to
maintain positive "G" forces during autorotation.
Touchdown should be accomplished prior to excessive
rotor RPM decay.
8-71. HOVERING CAPABILITY.
Refer to Chapter 7 for hover performance. Chapter
5 contains information on hover limitations.
8-72. SETTLING WITH POWER.
a. Settling with power is sometimes described as
"settling in your own downwash". This phrase is in
reality, quite descriptive since the helicopter finds itself
entering air which has just previously been accelerated
downward
by
the
rotor.
Settling
Change 16 8-22A
TM 55-1520-234-10
Figure 8-4A. Factors Causing High Flapping Angles Which May Result in Mast Bumping.
Change 16 8-22B
TM 55-1520-234-10
with power is a transient condition of downward flight
during which an appreciable portion of the main rotor
system is being forced to operate at angles of attack
above maximum. Tuft studies show that blade stall
starts in near the hub and progresses outward along the
blade as the rate of descent increases. The application
of collective pitch and power results only in stalling more
of the blade area and producing an even more rapid
descent rate. It follows that since inboard portions of the
blades are stalled, cyclic control response will be
reduced accordingly.
b. "Settling" can be quite hazardous if
inadvertently entered near the ground. Rates of descent
exceeding 2200 feet per minute have been recorded
during this state of flight. The characteristics of settling
are very similar to the "feel" of stall in a conventional
aircraft (Roughness in the airframe and controls and
some loss of control effectiveness). The recovery
procedure is also approximately the same, i.e., drop the
nose and accelerate into forward flight. Recovery can
also be made by reducing collective to the minimum
which will almost immediately result in vertical
autorotation.
This procedure, however, results in
considerable altitude loss.
8-73. ROTOR RPM - POWER OFF.
The following steps list the factors which affect poweroff rotor rpm.
a. Airspeed. In autorotation, rotor rpm varies with
airspeed. Maximum rotor rpm is achieved at a steady
state of 60 to 80 knots (Figure 8-5). Rotor rpm
decreases at stabilized airspeeds above or below 60 to
80 knot range.
When changing airspeeds, cyclic
movement will produce a rotor rpm other than that
produced under steady state conditions as follows:
(1) From low airspeed. Example: From a
stabilized 30 knot autorotative condition, a positive
forward cyclic movement to increase airspeed will cause
the rotor rpm to decrease initially and then increase
when the helicopter is stabilized at the higher speed.
Figure 8-5. Main rotor rpm versus airspeed
8-23
TM 55-1520-234-10
assures safe clearance between the rotor and the
tailboom.
(2) From high airspeed. Example: From a
stabilized 120 KIAS autorotative condition, a positive aft
cyclic movement to decrease airspeed will cause the
rotor rpm to increase initially and then decrease when
the helicopter is stabilized at the lower speed.
c. Rotor Inertia. Rotor inertia is a characteristic
which tends to prolong the effectiveness of collective
control in the autorotation landing. This effectiveness
decreases with rpm. Normal rotor rpm assures the pilot
that he will have normal inertia and normal collective
control response with which to arrest the sink rate in the
autorotation landing. The minimum blade angle rigging
is dictated by the minimum autorotation rpm
requirement (295) when at light gross weight and low
altitude.
b. Gross Weight. The power-off rotor rpm varies
significantly with gross weight. A low gross weight will
produce a low rotor rpm. A high gross weight will
produce a high rotor rpm. With the collective system
correctly rigged to a minimum blade angle (full down
collective stick) of approximately 8.5 degrees, the pilot
must manually control rpm with the collective stick in
order to prevent overspeed of the rotor when at high
gross weight.
d. Density Altitude. The power off rotor rpm varies
with altitude; low altitude - low rpm; high altitude - high
rpm. For the same flight conditions as in step a., the
pilot will find that the higher the altitude - the higher the
collective stick position required to prevent overspeed of
the rotor.
8-74. LEVEL FLIGHT CHARACTERISTICS.
The level flight characteristics of this helicopter are
normal throughout the operating limits range. All control
response is immediate and gives positive results.
e. Cyclic Flare. Aft cyclic control application (nose
up pitching) produces an increase in rotor rpm
proportional to the flare and entry speed. The higher the
speed the greater the flare effectiveness. From a high
speed entry condition, a steep flare can produce an
overspeed unless limited by collective pitch control.
8-75. AUTOROTATION CHARACTERISTICS.
The following steps explain the necessity of
maintaining the rotor rpm in its normal range.
a. Normal Rotor Speed. The normal rotor speed
assures the pilot that he will retain adequate control
effectiveness.
Low rpm (underspeed) causes a
proportional loss of response to control inputs. High rpm
(overspeed) can cause structural damage to the rotor
system.
8-76. PILOT TECHNIQUE.
It can be readily seen from the foregoing
information, that the pilot technique must vary in
accordance with the actual conditions of airspeed,
altitude, and gross weight at the time of engine failure.
b. Rotor Flapping. The angle between the tip path
plane and the mast increases at low rpm.
By
maintaining rotor rpm in the normal range, the pilot
Section V. ADVERSE ENVIRONMENTAL CONDITIONS
This section provides information relative to
operation under adverse environmental conditions
(snow, ice and rain, turbulent air, extreme cold and hot
weather, desert operations, mountainous and altitude
operation) at maximum gross weight.
Section II check list provides for operational requirement
of this section.
and conditions that may exist because of the lower
temperatures and freezing moisture.
a. Inspection. The pilot must be more thorough in
the walk-around inspection when temperatures have
been at or below 0°C (32°F). Water and snow may
have entered many parts during operations or in periods
when the helicopter was parked unsheltered. This
moisture often remains to form ice which will immobilize
moving parts or damage structure by expansion and will
occasionally foul electric circuitry. Protection covers
afford majority protection against rain, freezing rain,
8-77. COLD WEATHER OPERATIONS.
Operation of the helicopter in cold weather or an
arctic environment presents no unusual problems if the
operators are aware of those changes that do take place
8-24
TM 55-1520-234-10
sleet, and snow when installed on a dry helicopter prior
to the precipitation. Since it is not practicable to
completely cover an unsheltered helicopter, those parts
not protected by covers and those adjacent to cover
overlap and joints require closer attention, especially
after a blowing snow or freezing rain. Accumulation of
snow and ice should be removed prior to flight. Failure
to do so can result in hazardous flight, due to
aerodynamic and center of gravity disturbances as well
as the introduction of snow, water, and ice into internal
moving parts and electrical systems. The pilot should
be particularly attentive to the main and tail rotor
systems and their exposed control linkages.
CAUTION
At temperatures of -35°C (-31°F) and
lower, the grease in the spherical
couplings of the main transmission
driveshaft and tail rotor driveshaft
couplings may congeal to a point
that the couplings cannot operate
properly. If found frozen, apply heat
to thaw the couplings before
attempting to start the engine.
Indication of proper operation is
obtained by turning the main rotor
blade opposite to the direction of
rotation while observer watches the
driveshaft to see that there is no
tendency for the transmission to
"wobble" while the driveshaft is
turning.
CAUTION
Check that all surfaces and controls
are free of ice and snow.
NOTE
Contraction of the fluids in the
helicopter system at extreme low
temperature causes indication of low
levels. A check made just after the
previous shutdown and carried
forward to the walk around check is
satisfactory if no leaks are in
evidence. Filling when the system is
cold-soaked will reveal an over-full
condition immediately after flight,
with the possibility of forced leaks at
seals.
(a) Main Rotor -Check free of ice, frost,
and snow.
(b) Engine air inlet - Remove all loose
snow that could be pulled into and block the engine
intake during starting.
(3) Interior check -all flights 0°C (32°F) to 54°C (-65°F). Perform check as specified in Section II.
(4) Interior check -night flights 0°C (32°F) to 54°C (-65°F). External Power connected, Perform
check as specified in Section II.
(5) Engine starting check 0°C (32°F) to -54°C
(-65°F). Determine that the compressor rotor turns
freely. As the engine cools to an ambient temperature
below 0°C (32°F) after engine shutdown condensed
moisture may freeze engine seals. Ducting hot air from
an external source through the air inlet housing will free
a frozen rotor. Perform check as outlined in Section II .
CAUTION
If temperature is -44°C (-47°F) or
below the pilot must be particularly
careful
to
monitor
engine
instruments for high oil pressure.
b. Checks.
(1) Before exterior check 0°C (32°F) and
lower. Perform check as specified in Section II.
(2) Exterior check 0°C (32°F) to -54°C (65°F). Perform exterior check as outlined in Section II,
plus the following checks.
Change 9 8-25
NOTE
During cold weather starting the
engine oil pressure gage will indicate
maximum (100 psi).
The engine
should be warmed up at engine idle
until the engine oil pressure
indication is below 100 psi. The time
required for warmup is entirely
dependent
on
the
starting
temperature of the engine and
lubrication system.
TM 55-1520-234-10
(2) Before attempting to takeoff make sure
the landing gear skids are free and not frozen to the
surface.
(6) Hydraulic filter indicators - Reset if
popped out.
(7) Engine runup check. Perform the check
as outlined in Section II.
WARNING
Control system checks should be
performed with extreme caution
when helicopter is parked on snow
and ice.
There is reduction in
ground
friction
holding
the
helicopter stationary, controls are
sensitive and response is immediate.
(3) The first takeoff after a cold start should
include a visual check of the ground surface for
evidence of hydraulic leaks. This should be done under
hovering power conditions.
If hydraulic leaks are
present, abort the mission.
b. Landing - Snow.
Snow landing may be
considered normal except for the following precautions
that should be observed:
(1) Select an area free of loose or powdery
snow so that visibility will not be restricted by blowing
snow.
c. Engine Starting Without External Power Supply.
If a battery start must be attempted when the helicopter
and battery have been cold-soaked at temperatures
between -26°C to -37°C (-15°F to -35°F), preheat the
engine and battery if equipment is available and time
permits.
Preheating will result in a faster starter
cranking speed which tends to reduce the hot start
hazard by assisting the engine to reach a self-sustaining
speed (40% N1) in the least possible time.
(2) Accomplish a normal landing to the
ground. Limited visibility will result from swirling snow,
when hovering is attempted before making a
touchdown.
(3) Anticipate loose powdery snow and crusts
on all landings on snow.
(4) Landings should always be made when
visual ground reference can be maintained.
The
reference point should be kept forward and to the right
so that it will be visible to the pilot at all times.
NOTE
When making an approach and
landing on snow it should be one
continuous
operation
without
extended hover in order to reduce
the white-out condition that results
from extended hovering over snow.
This white-out will usually occur on
loose snow and can cause the pilot
to lose all reference with the ground
or any object he is approaching. If
the object being used as reference
should
become
completely
obscured, accomplish a go-round.
8-78. SNOW.
a. Takeoff. Snow takeoff may be considered
normal except for the following precautions that should
be observed.
WARNING
Under cold weather conditions, make
sure all instruments have sufficient
warm up time to ensure normal
operation.
Check
for
sluggish
instruments before takeoff.
(1) Select an area that is free of loose or
powdery snow to minimize the restriction to visibility
from blowing snow.
WARNING
Due to air starvation, snow and ice
accumulation
during
ground
operation may be detrimental to the
engine and hazardous to the
helicopter and crew.
Ground
operation time should be minimized
and FOD screen and particle
separator must be inspected prior to
takeoff.
8-79. DESERTAND HOTWEATHER OPERATION.
Problems encountered in desert operation are blowing
dust/sand and high ambient temperature.
a. Blowing dust and sand obscure vision. All
takeoffs and landings should be made from or to the
ground.
b. High ambient temperature affect helicopters
performance. Refer to Chapter 7.
8-26
TM 55-1520-234-10
8-80. TURBULENCE AND THUNDERSTORMS.
Flight in thunderstorm and heavy rain which
accompanies thunderstorms should be avoided. If
turbulence and thunderstorms are encountered
inadvertently, use the following procedures:
a. Check that safety belts and harnesses are
tightened.
b. Pitot heat -ON.
8-81. ICING CONDITIONS.
WARNING
Firing of aircraft weapons in icing
conditions is prohibited.
The
weapons covered are: TOW missile,
2.75 inch FFAR, 40MM Grenade
Launcher, 20MM Gun and 7.62MM
MG.
A very serious safety hazard exists if
aircraft weapons are fired In icing
weather conditions.
The TOW
missile warhead can detonate in
close proximity to aircraft.
The
warhead fuse Is damaged as missile
is launched through ice in missile
launcher. Gun barrels and breechs
can rupture if gun muzzles are
clogged with ice. The FFAR are held
captive in the launcher tubes by the
frozen ice.
c. Power - Adjust to maintain a penetration speed
of 100 KIAS.
NOTE
The turbulence penetration speed is
100 KIAS.
d. Radios - Turn volume down on any radio
equipment badly affected by static.
e. At night - Turn interior lights to full bright to
minimize blinding effect of lightning.
f. Maintain a level attitude and constant power
setting. Airspeed fluctuations should be expected and
disregarded.
CAUTON
Continuous flight in light icing
conditions is not recommended
because the ice shedding induces
rotor blade vibrations, adding greatly
to the pilots workload.
g. Maintain the original heading, turning only when
necessary.
h. The altimeter is unreliable due to differential
barometric pressures within the storm. An indicated
gain or loss of several hundred feet is not uncommon
and should be allowed for in determining minimum safe
altitude.
During flight in icing conditions, the pilot can expect
one or all of the following to occur.
a At any temperature below freezing, a low
frequency main blade vibration, caused by asymmetric
self-shedding ice.
b. To maintain airspeed, the torque must be
increased.
c. An increase in engine TGT.
Change 6 8-27
TM 55-1520-234-10
SECTION VI - CREW DUTIES
8-82. PASSENGER BRIEFING
The following is a guide that should be used in
accomplishing required passenger briefings, when a unit
passenger briefing is not available. Items that do not
pertain to specific mission may be omitted.
a. Crew Introduction
(3) Seat belts.
(4) Movement in aircraft.
(5) Internal communications.
(6) Security of equipment.
(7) Smoking.
b. Equipment
(1) Personal to include ID tags.
(8) Oxygen.
(2) Professional.
(9) Refueling.
(10) Weapons.
(3) Survival.
(11) Protective masks.
c. Flight Data
(12) Parachutes.
(1) Route.
(2) Altitude.
e. Emergency Procedures
(3) Time en route.
(1) Emergency exits.
(4) Weather.
(2) Emergency equipment.
(3) Emergency landing/ditching procedures.
d. Normal Procedures
(4) Bail out.
(1) Entry and exit of aircraft.
GPO 817-685
(2) Seating.
Change 6 8-28
TM 55-1520-234-10
CHAPTER 9
EMERGENCY PROCEDURES
Section I. HELICOPTER SYSTEMS
9-1. HELICOPTER SYSTEMS.
This section describes the helicopter systems
emergencies that may reasonably be expected to occur
and presents the procedures to be followed. Emergency
operation of mission equipment is contained in this
chapter insofar as its use affects safety of flight.
Emergency procedures are given in checklist form when
applicable. A condensed version of these procedures is
contained in the condensed checklist, TM 55-1520-234CL.
9-2. IMMEDIATE ACTION EMERGENCY STEPS.
9-3. DEFINITION OF EMERGENCY TERMS.
For the purpose of standardization, these definitions
shall apply.
a. The term "LAND AS SOON AS POSSIBLE" is
defined as landing at the nearest suitable landing area
(e.g., open field) without delay. (The primary
consideration is to ensure the survival of occupants.)
b. The term "LAND AS SOON AS PRACTICABLE"
is defined as landing at a suitable landing area. (The
primary consideration is the urgency of the emergency.)
c. The term "AUTOROTATE" is defined as
adjusting the flight controls as necessary to establish an
autorotational descent and landing.
WARNING
To obtain maximum protection from
the restraint system during an
emergency
landing,
each
crewmember should place their
shoulders against the seat back,
manually lock the shoulder harness,
and keep back straight.
1. Collective-Adjust as required to maintain
rotor RPM.
2. Pedals-Adjust as required.
3. Throttle-Adjust.
4. Airspeed-Adjust as required.
NOTE
The urgency of certain emergencies
requires immediate and instinctive
action by the pilot.
The
most
important
single
consideration is helicopter control.
All procedures are subordinate to
this requirement.
The MASTER
CAUTION should be reset after each
malfunction to allow systems to
respond
to
subsequent
malfunctions. If time permits during
a critical emergency, transmit a MAY
DAY CALL, set transponder to
emergency jettison external stores (if
appropriate), and lock shoulder
harnesses.
5. Wing stores-Jettison as appropriate.
d. The term "EMER SHUTDOWN" is defined as
engine shutdown without delay.
1. Throttle-OFF.
2. FUEL switch-OFF.
3. BAT switch-OFF.
e. The term "EMER GOV OPNS" is defined as
manual control of the engine RPM with the GOV
AUTO/EMER switch in the EMER position, Because
automatic acceleration, deceleration, and overspeed
control are not provided with the GOV switch in the
EMER position, throttle and collective coordinated
control movements must be smooth to prevent
compressor stall, overspeed, overtemperature, or
engine failure.
Those steps that must be performed immediately in
an emergency situation are underlined. These steps
must be committed to memory and performed without
reference to the checklist. Emergency situations with
non-underlined steps may be accomplished with use of
the checklist.
Change 22 9-1
CAUTION
No more than 42 psi torque is
available in the EMER position due
to limited fuel flow and may be
significantly reduced based on
ambient conditions.
TM 55-1520-234-10
1. GOV switch-EMER.
2. Throttle-Adjust as necessary to control
RPM
3. Land as soon as possible.
f. The term "JETTISON CANOPY" is defined as
activation of the linear explosive canopy removal
system to remove windows and separate doors from the
helicopter. Emergency exits are shown in Figure 9-1.
WARNING
Activation of the canopy removal
systems
when
combustible
fuel/vapors are present can result in
an explosion/fire.
Crew members
survival knife may be used as an
alternate means of egress.
1. Arming/firing mechanism
handle-Turn
90°.
2. Arming/firing mechanism handle-Pull.
WARNING
Simultaneous or near simultaneous
pulling of both the pilot's and
gunner's arming/firing mechanism
handle may result in injury to one or
both of the crewmembers. The pilot
must coordinate with the gunner
prior to system firing.
9-4. AFTER EMERGENCY ACTION.
After a malfunction of equipment has occurred,
appropriate emergency actions have been taken and the
helicopter is on the ground, an entry shall be made in
the Remarks Section of DA Form 2408-13 describing
the malfunction. Ground and flight operations shall be
discontinued until corrective action has been taken.
9-5. EMERGENCY ENTRANCE.
Crew removal is accomplished through the crew
doors or through the windows with crash rescue
equipment.
9-6. EMERGENCY EQUIPMENT.
Emergency equipment consists of a fire
extinguisher, first aid kit, and linear explosives canopy
removal system. (Refer to Figure 9-1.) Wing store
jettison capability is provided by explosive cartridges
installed at each wing store pylon.
9-7. MINIMUM RATE OF DESCENT.
The speed for minimum rate of descent is 60 KIAS.
Figure 9-1. Emergency exits and equipment
Change 29 9-2
TM 55-1520-234-10
WARNING
Do not close the throttle. Prior to reducing
collective after RPM warning audio and light
activation, first verify the engine failure by
cross checking other indications.
When a loss of engine power is detected, it is necessary
to decrease the collective pitch and apply right pedal
immediately in order to avoid a reduction in rotor RPM
and to maintain a constant heading. An exception to
this statement occurs during engine failures above 120
KIAS. Under partial power conditions the engine may
operate relatively smooth at reduced power or it may
operate roughly and erratically with intermittent surges
of power.
In instances where a power loss is
experienced without accompanying engine roughness or
surging, the helicopter may sometimes be flown in a
gradual descent at reduced power to a more favorable
landing area; however, under these conditions the pilot
should always be prepared for a complete power failure
an immediate autorotative landing. In the event that a
partial power condition is accompanied by engine
roughness, erratic operation or power surging, take
immediate action by closing the throttle completely and
accomplish an
Change 7 9-2A/(9-2B blank)
TM 55-1520-234-10
9-8. MAXIMUM GLIDE DISTANCE.
The speed for best glide distance is 100 KIAS (clean
configuration) and 90 KIAS (wing stores).
9-9. ENGINE.
9-10. ENGINE MALFUNCTION-PARTIAL OR
COMPLETE POWER LOSS.
a. The indications of an engine malfunction, either
a partial or a complete power loss are left yaw, drop in
engine rpm, drop in rotor rpm, drop in N1, low rpm audio
alarm, illumination of the rpm warning light, change in
engine noise.
WARNING
Do not respond to the rpm audio
and/or warning light illumination
without first confirming engine
malfunction by one or more of the
other
indications.
Normal
indications signify the engine is
functioning properly and that there is
a tachometer generator failure or an
open circuit to the warning system,
rather than an actual engine
malfunction.
b. Partial power loss.
Under partial power
conditions, the engine may operate relatively smoothly
at reduced power or it may operate erratically with
intermittent surges of power. A stabilization of the N1
should indicate a partial power condition. In instances
where a power loss is experienced without
accompanying power surging, the helicopter may
sometimes be flown at reduced power to a favorable
landing area. Under these conditions, the pilot should
always be prepared for a complete power loss. In the
event a partial power condition is accompanied by
erratic engine operation or power surging, and flight is to
be continued, perform EMER GOV operations. If
continued flight is not possible, AUTOROTATE (throttle
off).
c. Complete power loss.
(1) Under a complete power loss condition,
delay in recognition of the malfunction, improper
technique or excessive maneuvering to reach a suitable
landing area reduces the probability of a safe
autorotational landing. Flight conducted within the
caution area of the height-velocity chart (fig. 9-2)
exposes the helicopter to a high probability of damage
despite the best efforts of the pilot.
(2) From conditions of low airspeed and low
altitude, the deceleration capability is limited, and
caution should be used to avoid striking the ground with
the tail rotor. Initial collective reduction will vary after an
engine malfunction dependent upon the altitude and
airspeed at the time of the occurrence. For example,
collective pitch must not be decreased when an engine
failure occurs at zero airspeed and approximately 15
feet; whereas, during cruise flight conditions, altitude
and airspeed are sufficient for a significant reduction in
collective pitch, thereby, allowing rotor rpm to be
maintained in the safe operating range during
autorotational descent. At high gross weights, the rotor
may tend to overspeed and require collective pitch
application to maintain the rpm below the upper limit.
Collective pitch should never be applied to reduce rpm
below normal limits for extending glide distance
because of the reduction in rpm available for use during
autorotational landing.
(3) Through a speed range of 120 to 190
KIAS, an engine failure will cause the nose of the
helicopter to pitch up as a result of its aerodynamic
qualities. The SCAS system detects this airframe
movement and will attempt to correct with a forward
cyclic control input, thereby causing serious rotor
flapping and possible mast bumping. To prevent SCAS
from making this correction there must be pilot input. In
a nose-low attitude or level flight, the input should be aft
cyclic movement. In a nose-high attitude, such as dive
pullout, the input should be a forward cyclic movement.
During the recovery from a high-speed engine failure,
the important point to remember is to maintain the
necessary rotor rpm and movement to keep the rotor
system loaded.
Speed should be reduced to
successfully reach the intended landing area. After
entering autorotation, follow standard autorotation
procedures. Do not exceed 120 KIAS in sustained
autorotation.
CAUTION
Engine failure at 150 KIAS and
greater requires a pilot recognition
and reaction time of less than one
second to preclude unacceptable
high left roll rates. Heavy buffeting
of the tailboom and vertical fin and
heavy control feedback during
recovery are associated with engine
failure at high speed and high power
conditions.
9-11. ENGINE MALFUNCTION - HOVER.
AUTOROTATE
9-12. ENGINE MALFUNCTION-LOW ALTITUDE/LOW
AIRSPEED OR CRUISE.
1. AUTOROTATE.
2. EMER GOV OPNS.
Change 19 9-3
TM 55-1520-234-10
Figure 9-2. Minimum height for safe landing after engine failure chart
Change 19 9-4
TM 55-1520-234-10
9-13. ENGINE MALFUNCTION- 1120 KIAS AND
ABOVE.
1. CYCLIC-Adjust.
2. AUTOROTATE.
3. EMER GOV OPNS.
9-14. Deleted.
9-15. DROOP COMPENSATOR FAILURE.
Droop compensator failure will be indicated when
engine rpm is no longer controlled by application of
collective pitch. The engine will tend to overspeed as
collective pitch is decreased and will underspeed as
collective pitch is increased. If the droop compensator
fails, make minimum collective movements and execute
a shallow approach to the landing area. If unable to
maintain the operating RPM within limits:
.b If the inlet guide vanes fail in the open position
during normal flight, it is likely that no indications will be
experienced. As power applications are made from
increasingly lower N1 settings, acceleration times will
correspondingly increase, and the possibility of a
compressor stall is likely. Should this failure occur, land
as soon as practicable to an area that will permit a runon landing.
9-18. ENGINE OVERSPEED.
Engine overspeed will be indicated by a right yaw,
rapid increase in both rotor and engine rpm, rpm
warning light illuminated, and an increase in engine
noise. An engine overspeed may be caused by a
malfunctioning N2 governor or fuel control. If an
overspeed is experienced:
1. Collective-Increase to load the rotor in an
attempt to maintain rpm below the
maximum operating limit.
2. Throttle-Reduce to normal operating rpm.
If rpm cannot be controlled:
EMER GOV OPNS.
9-16. ENGINE COMPRESSOR STALL.
Engine compressor stall (surge) is characterized by
a sharp rumble or loud sharp reports, severe engine
vibration, and a rapid rise in turbine gas temperature,
depending on the severity of the surge. Maneuvers
requiring rapid or maximum power applications should
be avoided. Should this occur:
1. Collective-Reduce.
2. RAIN REMOVALIENVR CONT switch-OFF.
3. DE-ICE switch-OFF.
4. Land as soon as possible.
9-17. INLET GUIDE VANE ACTUATOR FAILURE.
a. If the guide vanes fail in the closed position, a
maximum of 20-25 psi torque will be available.
Although N1 may indicate normal, power applications
above 20-25 psi will result in deterioration of N2 and
rotor rpm while increasing N1. Placing the GOV switch
in the EMER position will not provide any increased
power capability and increases the possibility of an N1
overspeed and an engine overtemperature. Should a
failure occur, land as soon as practicable to an area that
will permit a run-on landing with minimum power
applications.
3. EMER GOV OPNS.
9-18A. ENGINE OIL TEMPERATURE HIGH.
If the engine oil temperature exceeds the operating
limits specified in Chapter 5, land as soon as possible.
9-19. ROTORS, TRANSMISSION, AND DRIVE
SYSTEMS.
9-20. TAIL ROTOR FAILURE-FLIGHT.
Because of the many different malfunctions that can
occur, it is not possible to provide a solution for every
emergency. The success in coping with the emergency
depends on quick analysis of the condition and selection
of the proper emergency procedure. The following is a
discussion of some types of malfunctions, probable
effects, and corrective actions.
a. Complete Loss of Thrust Components.
(1) Complete Loss of Tail Rotor Thrust. This
is a situation involving a break in the drive system, such
as a severed driveshaft, wherein the tail rotor stops
turning and no thrust is delivered by the tail rotor. A
failure of this type in powered flight will usually result in
the nose of the helicopter swinging to the right (left side
slip) and usually a roll of the fuselage.
Change 30 9-5
TM 55-1520-234-10
Nose down tucking will also be present. If powered
flight is possible, continue to a suitable landing area and
AUTOROTATE (throttle off), and coordinate the
resulting maneuver with cyclic control.
The most
advisable procedure, if further flight is not possible, is to
immediately AUTOROTATE (throttle off). The pilot
should expect that some rotation will be present until
touchdown. Touchdown should be in as level an
attitude as possible and ground speed as low as
possible to minimize turnover.
(2) Loss of Tail Rotor Components. Except
for a more severe nose tuck due to the forward cg shift,
this situation would be quite similar to a complete loss of
thrust as discussed above. When a loss of components
is suspected, AUTOROTATE (throttle off).
landing can be performed. If the right yaw becomes
excessive when adding power at touchdown, reduce the
throttle and cushion the landing with collective. The
greatest problem is the compromise that may have to be
made between rate of descent and yaw attitude since
the collective is the primary control for both of these
parameters.
9-21. TAIL ROTOR FAILURE-HOVER.
a. If the tail rotor pitch is fixed in a left pedal
position, simultaneously reduce throttle and gradually
increase collective pitch to land the helicopter.
b. If total loss of tail rotor thrust/fixed right pedal is
experienced:
b. Fixed Pitch Failure.
1. Throttle-Reduce.
(1) Gel. Failures of this type (wedged control,
jammed slider, etc.) are characterized by either a lack of
directional response when a pedal is pushed or the
pedals will be in a locked position. At approximately
100 KIAS and above, the cambered vertical fin Will
begin to become more effective and as a result, a left
yaw condition will increase and conversely, a right yaw
will decrease. To aid in directional control, the rpm may
be decreased with the throttle until rpm is controlled
manually. Increasing the throttle and/or collective will
move the nose to the right, decreasing the throttle
and/or collective will move the nose to the left.
WARNING
If the pedals cannot be moved with a
moderate amount of force, do not
attempt a maximum effort since a
more serious malfunction and set of
circumstances could result.
(2) Left fixed pitch. If it has been determined
the tail rotor pitch is fixed in a left pedal applied position,
an autorotative landing should not be attempted. The
pilot should use only that power necessary to produce a
controllable degree of side slip and continue to the
nearest suitable landing area. To accomplish a landing,
establish a powered approach with an airspeed that will
allow a desirable rate of descent without producing an
uncomfortable left yaw attitude and right side slip
condition. Just prior to landing, adjust throttle and
collective as necessary to align the helicopter with
touchdown.
(3) Right fixed pitch. If the tail rotor becomes
fixed during cruise flight or a reduced-power situation,
the helicopter will yaw to the right when power is
increased. For either of these situations, a running type
2. AUTOROTATE.
9-22. MAIN DRIVESHAFT FAILURE.
A failure of the main driveshaft will be indicated by a
left yaw (this is caused by the drop in torque applied to
the main rotor), increase in engine rpm, decrease in
rotor rpm, low rpm audio alarm, and illumination of the
rpm warning light. This condition will result in complete
loss of power to the rotor and a possible engine
overspeed. If a failure occurs:
1. AUTOROTATE.
2. Throttle-Off.
9-23. TRANSMISSION SPRAG CLUTCH
MALFUNCTION.
9-24. CLUTCH FAILS TO DISENGAGE
A clutch failing to disengage in flight will be
indicated by the rotor rpm decaying with engine rpm as
the throttle is reduced to the engine idle position when
entering autorotational descent. This condition results in
total loss of autorotational capability. If a failure occurs:
1. Throttle-On.
2. Land as soon as possible.
9-25. CLUTCH FAILS TO RE-ENGAGE.
During recovery from autorotational descent, clutch
malfunction may occur and will be indicated by a
reverse needle split (engine rpm higher than rotor rpm).
Change 24 9-6
TM 55-1520-234-10
1. AUTOROTATE.
b. Power-Off.
2. Throttle-OFF.
9-26. FIRE.
The safety of helicopter occupants is the primary
consideration when a fire occurs. On the ground, it is
essential that the engine be shut down, crew evacuated,
and fire fighting begun immediately. If the helicopter is
airborne when a fire occurs, the most important single
action that can be taken by the pilot is to land the
helicopter.
9-27. FIRE-ENGINE START.
The following procedure is applicable during engine
starting if TGT limits are exceeded, or if it becomes
apparent that they will be exceeded. Flames emitting
from the tailpipe are acceptable if the limits are not
exceeded.
1. Throttle-OFF.
2. FUEL switch-OFF.
3. Start switch-Press until TGT is in the
normal operating range.
9-28. FIRE-GROUND.
a. Pilot's station.
EMER SHUTDOWN.
b. Gunner's station.
1. AUTOROTATE.
2. EMER SHUTDOOWN.
9-30. ELECTRICAL FIRE-FLIGHT.
Prior to shutting off all electrical power, the pilot
must consider the equipment that is essential to a
particular flight environment that will be encountered;
e.g., flight instruments and fuel boost pumps. In the
event of electrical fire or suspected electrical fire in
flight:
1. BAT switch-ON.
2. Electrical switches OFF.
3. NON-ESS BUS switch-NORMAL.
4. Land as soon as possible.
5. EMER SHUTDOWN.
If landing cannot be made as soon as possible and
flight must be continued, the defective circuits may be
identified and isolated. Electrical switches should be
turned ON one at a time in the priority required. When
malfunctioning circuit is identified, turn switch off.
9-31. FUMES FROM ECU.
If fumes are emitted in the cockpit from the ECU
System:
1. ENVR CONT switch-OFF.
1. IDLE STOP-RELEASE and hold.
If fumes continue:
2. Throttle-OFF.
2. Land as soon as possible.
3. ELEC PWR switch-EMER OFF.
9-29. FIRE-FLIGHT.
If the fire light illuminates and/or fire is observed
during flight, prevailing circumstances (such as VFR,
IMC, night, altitude, and landing areas available), must
be considered in order to determine whether to execute
a power-on (max-Vne), or a power-off landing (max-120
KIAS).
a. Power-On.
1. Land as soon as possible.
9-32. SMOKE AND FUME ELIMINATION.
1. Vents-Open.
2. Airspeed-Reduce to 40 KIAS or below.
3. Canopy
doors-Open
to
intermediate
position.
9-33. DUAL FUEL BOOST PUMP FAILURE.
If both fuel boost caution lights come on:
1. Fuel pressure-Check.
2. EMER SHUTDOWN.
Change 30 9-7
TM 55-1520-234-10
2. Descend to a pressure altitude of 6000 or
less if possible.
3. Land as soon as practicable. No attempt
should be made to troubleshoot the
system while in flight.
CAUTION
Nose-down attitudes greater than 15
degrees should be avoided because
engine failure may occur due to fuel
starvation when the forward fuel
boost pump is inoperable and with
less than 320 pounds of fuel
remaining.
9-34. ELECTRICAL SYSTEM.
9-35. DC GENERATOR FAILURE-DC GENERATOR
CAUTION LIGHT ILWMINATION.
NOTE
As battery voltage is depleted there
is a possibility of activation of the
RPM warning light and RPM audio
systems.
1. GEN BUS RESET/GEN FIELD circuit
breakers-IN.
2. GEN switch-Move to RESET then to GEN
position.
If generator is not restored, continue as follows:
3. GEN switch-OFF.
4. TCP MODE SEL switch-OFF.
2. Land as soon as possible.
3. EMER SHUTDOWN.
WARNING
Do not open battery compartment
and attempt to disconnect or remove
overheated battery. Battery fluid will
cause burns and overheated battery
will cause thermal burns and may
explode.
9-38. HYDRAULIC SYSTEM FAILURE.
If a hydraulic malfunction should occur below an
airspeed of 40 KIAS, the pilot should turn on the
emergency hydraulic accumulator (as appropriate) and
land the aircraft as soon as possible. If terrain does not
permit a landing, accelerate the aircraft to the best
controllable airspeed above 40 KIAS and comply with
the appropriate failure that has occurred.
WARNING
The ability to increase collective
(torque) may be limited during a
single system failure and will be
limited during a dual system failure.
Collective once lowered may not be
able to be raised again; if altitude
cannot be maintained, jettison wing
stores as appropriate.
During a single system failure, do
not move hydraulic test switch to
failed system position.
Hydraulic
pressure to the good system will be
interrupted.
9-39. HYDRAULIC FAIWRE-SINGLE SYSTEM.
5. Switches-OFF for unused equipment.
Loss of system No. 1 will result in loss of tail rotor
servo, the yaw SCAS actuator, and the ability to charge
the accumulator. Loss of No. 2 hydraulic system will
result in loss of pitch and roll SCAS actuators. Cyclic
and collective control feedback may be evident during
abrupt maneuvers.
1. EMER COLL HYD switch-OFF (pilot and
gunner).
6. NON ESS BUS switch-As required.
9-36. AC INVERTER FAILURE-CAUTION LIGHT
ILLUMINATION.
1. INV MAIN/STBY circuit breakers-In.
2. INV switch-STBY.
3. SCAS-Re-engage.
2. HYD CONT circuit breaker-In.
9-37. OVERHEATED BATTERY.
If overheated battery is suspected or detected,
proceed as follows:
1. BAT switch-FF.
3. SCAS-DISENGAGE
channels.
appropriate
a. No. 1 system-Yaw channel.
b. No. 2 system-Pitch and
channels.
4. MASTER ARM switch-OFF.
5. PLT OVRD switch-OFF.
Change 30 9-8
roll
TM 55-1520-234-10
position, an autorotative landing should not be
attempted.
The pilot should use only that power
necessary to produce a controllable degree of side slip
and continue to the nearest suitable landing area. An
approach should then be established at an airspeed and
rate of descent which will not produce uncontrollable
side slip. During the approach, a right side slip condition
will most probably prevail. When power is applied just
prior to landing, the helicopter will yaw to the right,
reducing the side slip condition.
d. If the tail rotor pitch becomes fixed during cruise
flight or a reduced power situation (right pedal applied)
the helicopter will yaw to the right when power is
increased. For either of these situations, a running type
landing can be performed. If the right yaw becomes
excessive when adding power at touchdown, roll off the
throttle and cushion the landing with collective. The
greatest problem is the compromise that may have to be
made between rate of descent and yaw attitude since
the collective (power) is the primary
Change 15 9-8A/(9-8B blank)
TM 55-1520-234-10
6. Land as soon as practicable. A run-on
landing at a speed of 50 KIAS or above is
recommended.
7. EMER COLL HYD switch-ON
approach).
NOTE
The turret will return to the stow
position in elevation but will not
stow in azimuth.
(final
9-40. HYDRAULIC FAILURE-DUAL SYSTEM.
Loss of both hydraulic systems will result in loss of
hydraulic pressure to the SCAS actuators, cyclic,
collective, tail rotor servos, and the ability to charge the
accumulator.
WARNING
During power application above 35
psi, roll oscillations may become
unmanageable.
If oscillations
become severe, reduce collective
until oscillations are manageable.
Below 40 KIAS cyclic feedback
forces become unmanageable.
9-41. LANDING AND DITCHING.
9-42. LANDING IN TREES.
A landing in trees should be made when no other
landing area is available.
Select a landing area
containing the least number of trees of minimum height.
Decelerate to a zero ground speed at tree-top level and
descend into the trees vertically, applying collective
pitch as necessary for minimum rate of descent. Prior
to the main rotor blades entering the tree, ensure throttle
is off and apply all of the remaining collective pitch.
9-43. DITCHING- POWER ON.
If it becomes necessary to ditch the helicopter,
accomplish an approach to an approximate 3-foot hover
above the water and proceed as follows:
1. MASTER ARM-OFF.
2. PLTOVRD-OFF.
3. JETTISON CANOPY.
4. Gunner-Exit.
NOTE
Correct for cg shift of 2.5 to 4.0
inches when gunner exits helicopter.
5. Hover-Clear of gunner.
WARNING
Life preserver should not be inflated
until clear of helicopter.
6. Throttle-Off and autorotate. Apply full
collective pitch prior to the main rotor
blades entering the water. Maintain a
level attitude as the helicopter sinks and
until it begins to roll, then apply cyclic in
direction of the roll. Pilot should exit
when main rotor stops.
NOTE
The turret will return to the stow
position in elevation but will not
stow in azimuth.
1. EMER COLL HYD switch-OFF (pilot and
gunner).
2. HYD CONT circuit breaker-In.
3. SCAS-Disengage all channels.
4. MASTER ARM switch-OFF.
5. PLT OVRD switch-OFF.
6. Land as soon as practicable. A run-on
landing at a speed of 50 KIAS or above is
recommended.
7. EMER COLL HYD switch-ON
approach).
NOTE
When the collective pitch creeps
down, turn the COLL HYD switch on
and increase collective as required;
then, turn the system off.
This
procedure can be repeated as
required but must be kept to a
minimum
to
ensure
sufficient
collective movement will remain at
landing.
(final
9-44. DITCHING- POWER OFF.
If ditching is imminent, accomplish engine
malfunction emergency procedures. Decelerate to zero
forward speed, level helicopter and jettison canopy just
prior to entering the water. Apply collective pitch as the
helicopter sinks and until it begins to roll, then apply
cyclic in the direction of the roll. Exit when the main
rotor is stopped.
NOTE
There may be a tendency to
decelerate too high over water due to
depth perception.
Change 30 9-9
TM 55-1520-234-10
9-45. FLIGHT CONTROL/MAIN ROTOR SYSTEM
MALFUNCTIONS.
a. Failure of components within the flight control
system may be indicated through varying degrees of
feedback, binding, resistance, or sloppiness. These
conditions should not be mistaken for hydraulic power
failure.
b. Imminent failure of main rotor components may
be indicated by a sudden increase in main rotor
vibration and/or unusual noise. Severe changes in lift
characteristics and/or balance condition can occur due
to blade strikes, skin separation, shift or loss of balance
weights or other material. Malfunctions may result in
severe main rotor flapping. In the event of a main rotor
system malfunction, proceed as follows:
WARNING
Danger exists that the main rotor
system could collapse or separate
from the aircraft after landing. A
decision must be made whether
occupant egress occurs before or
after the rotor has stopped.
1. Land as soon as possible.
9-46. MAST BUMPING.
If mast bumping occurs:
1. Reduce severity of maneuver.
2. Land as soon as possible.
9-47. STABILITY AND CONTROL AUGMENTATION
SYSTEM (SCAS) FAILURE.
A failure of the SCAS will be evident by an abrupt
change in pitch, roll, and/or yaw attitude which, when
corrected by the pilot, will result in an abnormal cyclic or
pedal position. When SCAS is disengaged, a second
correction may be required by the pilot to return to level
flight. Mast bumping may occur. SCAS off flight is
limited to 100 KIAS MAXIMUM. Additionally, high
power settings should be avoided when operating at
airspeeds between 60 and 100 K[AS with inoperative roll
and yaw SCAS channel because of instability. If a
failure occurs, proceed as follows:
1. SAS REL button-Press.
If condition persists:
2. SCAS POWER switch-OFF.
3. Unaffected SCAS channel re-engage only
if power switch has not been turned off.
2. EMER SHUTDOWN.
4. Land as soon as practicable.
9-45A. LOW G WARNING.
1. Cyclic stick-Aft to return rotor to positive
thrust condition.
2. Reduce severity of maneuver.
9-48. DELETED.
9-49. IN FLIGHT WIRE STRIKE.
Land as soon as possible.
Section II. MISSION EQUIPMENT
9-50. WING STORES EMERGENCY JETTISON.
a. Pilot Wing Stores Jettison Procedures.
b. Gunner Wing Stores Jettison Procedures.
1. WG ST JETTISON SELECT switch-As
required.
2. WING STORES JETTISON switch-UP.
WING STORES JETTISON switch-UP.
9-51. TOW MISSILE EMERGENCY PROCEDURES.
a. Hangfire/misfire.
Change 30 9-10
TM 55-1520-234-10
9-37. FUSELAGE FIRE - FLIGHT.
If fire is observed in any part of the helicopter during
flight proceed as follows.
1. Land immediately - Perform a poweron approach and landing without
delay.
2. Throttle - Closed as soon as the
helicopter is on the ground.
3. FUEL switch -OFF.
4. BAT switch- OFF.
5. Clear helicopter.
9-38. ENGINE FIRE - FLIGHT.
9-39. LOW ALTITUDE.
If the fire is observed in or around the engine
compartment during flight at low altitude, proceed as
follows:
1. Land immediately - Perform a poweron approach and landing without
delay.
2. Throttle - Closed as soon as the
helicopter is on the ground.
3. FUEL Switch - OFF.
4. BAT switch - OFF.
5. Clear helicopter.
9-40. CRUISE ALTITUDE.
If fire is observed in or around the engine
compartment during flight at an altitude which will permit
the execution of an autorotational descent and landing,
proceed as follows:
1. Collective pitch - Down; autorotate.
2. Wing Stores - Jettison as appropriate.
Change 9 9-10A/(9-10B blank)
TM 55-1520-234-10
1. After landing-Ensure weapons are pointed
at safe area.
2. Armament switches-OFF.
3. Engine shutdown.
4. Helicopter-Exit 90 degrees from line of
fire.
b. Emergency Wire Cut. Should a power loss
occur to the TOW system which causes the M65 to
momentarily shut down, the system will automatically
return to a ready-to-fire mode. If the TCP MODE
SELECT switch is in ARMED MAN, then the gunner
must press his WIRE CUT to sever the wires to the
missile. If the TCP MODE SELECT switch is in ARMED
AUTO, the gunner must reset the TCP MODE SELECT
switch to manual and turn the MISSILE SELECT switch
just fired and then press the WIRE CUT switch to sever
wires to the missile just fired. If wire fails to cut, fly
helicopter in a crab away from the wire. Approach and
landing should be made in a crab to prevent entangling
wire with helicopter..
WIRE CUT switch-Press.
c. TOW Missile Flight Motor Failure.
WIRE CUT switch-Press.
d. TOW Missile Erratic in Flight.
1. Attempt to keep missile down range.
2. Emergency wire cut if needed.
9-52. RUNAWAY GUN.
1. MASTER ARM switch-OFF.
2. PLT OVRD switch-OFF.
Table 9-1. Emergency Procedures for Caution Segments (Pilot and Gunner Caution Panels)
Light
MASTER CAUTION
ENGINE OIL PRESS
ENGINE OIL BYPASS
XMSN OIL PRESS
XMSN OIL BYPASS
XMSN OIL HOT
ENG FUEL PUMP
CHIP DETECTOR
FUEL FILTER
SPARE
HYD PRESS #1
HYD PRESS #2
FWD FUEL BOOST
AFT FUEL BOOST
DC GENERATOR
INST INVERTER
GOV EMER
10% FUEL
IFF
EXTERNAL POWER
Corrective Action
(No segment.) Land as soon as possible.
Land as soon as possible.
Land as soon as possible.
Land as soon as possible.
Land as soon as possible.
Land as soon as possible.
Land as soon as possible.
Land as soon as possible.
Land as soon as possible.
Land as soon as possible.
Refer to EMER procedure.
Refer to EMER procedure.
Land as soon as practicable.
Land as soon as practicable.
Refer to EMER procedure.
Refer to EMER procedure.
Information/System Status.
Land as soon as practicable.
Information/System Status.
Close door.
Change 30 9-11/(9-12 blank)
TM 55-1520-234-10
3. GEN switch - Move to RESET then to
GEN position.
4. Generator - Not restored.
a. Gen switch - OFF.
b. GEN FIELD circuit breaker - Out.
c. Switches/circuit breakers - OFF
or pull for unused equipment.
d. NON-ESS
required.
BUS
switch-As
9-56. AC INVERTER FAILURE - CAUTION LIGHT
ILLUMINATION.
1. INV MAIN circuit breaker - In.
2. INV STBY circuit breaker - In.
WARNING
The ability to increase collective
(torque) may be limited during a
single system failure and will be
limited during a dual system failure.
Collective once lowered may not be
able to be raised again; if altitude
cannot be maintained, jettison wing
stores as appropriate.
CAUTION
Before further flight. the cause of
hydraulic failure shall be determined
and corrected.
9-58. HYDRAULIC SYSTEM NO. 1 FAILURE.
1. EMER COLL HYD switch - OFF pilot and
gunner.
3. INV switch - STBY.
2. HYD CONT circuit breaker - In.
4. SCAS - Re-engage.
3. SCAS - Disengage YAW channel.
5. INV MAIN circuit breaker - Out.
NOTE
Failure of the standby inverter will
again illuminate the INST INVERTER
caution light, then ac power is lost
completely.
9-57. HYDRAULIC SYSTEM FAILURE.
Procedures for the three combinations of hydraulic
failure are described in the following paragraphs.
WARNING
During a single system failure, do
not move hydraulic test switch to the
failed system position.
Hydraulic
pressure to the good system will be
interrupted.
4. MASTER ARM switch - OFF.
5. Land as soon as possible at an area that
will permit a running landing.
NOTE
Touchdown speed of 50 KIAS is
recommended, terrain permitting.
6. EMER COLI, HYD switch - ON (final
approach).
NOTE
Loss of system No. 1 will result in
loss of tail rotor boost, the
directional control SCAS actuator,
and the ability to charge the
accumulator. Cyclic and collective
control feedback may be evident
during abrupt maneuvers.
Change 18 9-12A/(9-12B blank)
TM 55-1520-234-10
9-59. HYDRAULIC SYSTEM NO. 2 FAILURE.
1. EMER COLL HYD switch - OFF pilot and
gunner.
2. HYD CONT circuit breaker - In.
3. SCAS - Disengage PITCH and ROLL
channels.
4. MASTER ARM switch - OFF.
WARNING
Below 40 KIAS cyclic feedback
forces become uncontrollable.
5. Airspeed - Maintain speed where control
forces are manageable.
4. MASTER ARM switch - OFF.
5. Land as soon as possible at an area that
will permit a running landing.
NOTE
Touchdown speed of 50 KIAS is
recommended, terrain permitting.
6. EMER COLL HYD switch - ON (final
approach).
NOTE
Loss of the No. 2 hydraulic system
will result in loss of pitch -and roll
SCAS actuators.
The turret will
return to the stow position in
elevation; however, it will not stow in
azimuth.
Cyclic and collective
control feedback may be evident
during abrupt maneuvers.
9-60. HYDRAULIC SYSTEM NO. 1 AND NO. 2
FAILURE.
1. EMER COLL HYD switch - OFF pilot and
gunner.
2. HYD CONT circuit breaker - In.
WARNING
During power application above 35
PSI torque, roll oscillations may
become unmanageable.
If roll
oscillations become severe, reduce
collective until control can be
maintained.
6. Land as soon as possible at an area that
will permit a running landing.
NOTE
Touchdown speed of 50 KIAS is
recommended, terrain permitting.
CAUTION
With the EMER COLL HYD switch in
the ON position, collective motion
must be kept to a minimum until
touchdown
so
that
sufficient
collective
control
remains
to
accomplish a landing.
7. EMER COLL HYD switch - ON (final
approach).
3. SCAS - Disengage all channels.
Change 18 9-13
TM 55-1520-234-10
NOTE
Loss of both hydraulic systems will
result in loss of the SCAS actuators,
cyclic, collective and tail rotor boost,
and loss of directional control of the
turret. The turret will return to the
stow position in elevation; however,
it will not stow in azimuth.
7. Accomplish a hovering autorotation, as
helicopter settled into the water dissipate
rotor rpm by holding the helicopter up and
level as long as possible; if helicopter
starts to roll, assist with cyclic in direction
the helicopter tends to roll.
8. Exit helicopter when main rotor stops.
WARNING
9-61. LANDING AND DITCHING.
Do not inflate life preserver until
clear of helicopter.
9-62. EMERGENCY DESCENT.
a. Power Off.
1. Throttle - Off.
2. Collective adjust - Maintain rotor 295 324.
3. Cyclic adjust - Power off VNE.
NOTE
Turns will increase rate of descent.
b. Power On.
9-65. DITCHING - POWER OFF.
(0)
1. Wing stores - Jettison 2. Arming/Firing
handle - ARM.
3. Execute zero groundspeed autorotation.
After leveling helicopter, pull handle to
remove doors and windows.
4. As helicopter settles into water, dissipate
rotor rpm by holding helicopter up and
level as long as possible; if helicopter
starts to roll, assist with cyclic in the
direction of roll.
1. Collective - adjust.
2. Cyclic adjust - Main VNE.
9-63. LANDING IN TREES.
Decelerate to a zero ground speed at tree-top level
and descent into the trees vertically applying collective
pitch as necessary for minimum rate of descent. Prior
to the main rotor blades entering the trees, apply all of
the remaining collective pitch.
9-64. DITCHING - POWER ON.
(0)
1. Wing stores - Jettison 2. Airspeed hover.
3. MASTER ARM/PLT OVRD - OFF.
4. Arming/Firing handle - Turn 90°- Pull.
5. Gunner - Exit.
NOTE
Correct for cg shift of 2.5 to 4.0
inches when gunner exits helicopter.
6. Hover - Clear of gunner.
5. Exit helicopter when main rotor stops.
WARNING
Do not inflate life preserver until
clear of helicopter.
9-66. FLIGHT CONTROLS.
Refer to hydraulic system failure procedures contained
in this chapter.
9-67. STABILITY AND CONTROL AUGMENTATION
SYSTEM (SCAS) FAILURE.
A failure of the SCAS will be evident by an abrupt
change in pitch, roll, and yaw attitude which, when
corrected by the pilot will result in an abnormal cyclic or
pedal position. Mast bumping may occur. SCAS off
flight is limited to 100 KIAS MAXIMUM. Additionally,
high power settings should be avoided when operating
at airspeeds between 60 and 100 KIAS with inoperative
roll or yaw SCAS channel because of instability. If a
failure occurs, proceed as follows:
Change 16 9-14
TM 55-1520-234-10
1. SCAS REL button-Press.
5. Bailout - When ready.
2. If condition persists, SCAS Power switchOFF.
3. After attitude and airspeed control has
been reestablished, the pilot may
reengage the unaffected SCAS channels.
4. Land as soon as practicable.
9-68. BAILOUT PROCEDURES.
a. Helicopter In Control.
1. FORCE TRIM switches - TRIM.
2. Attitude - Stabilize helicopter in a shallow
descent at approximately 80 KIAS.
3. Wing Stores - Jettison.
4. Canopy - Jettison
WARNING
Delay opening parachute until well
clear of helicopter.
b. Helicopter Out Of Control.
1. Attitude - Attempt to keep helicopter
upright.
2. Door/Canopy - Open or jettison.
WARNING
Delay opening parachute until well
clear of helicopter.
3. Bailout - When ready.
9-69. WING STORES EMERGENCY JETTISON.
a. Pilot wing stores jettison procedures.
(1) WG ST JETTISON SELECT switch - as
required.
(2} WING STORES JETTISON switch Up.
b. Gunner wing stores jettison procedures.
WING STORES JETTISON switch - Up.
Section II. MISSION EQUIPMENT
9-70. TOW MISSILE EMERGENCY PROCEDURES.
a. Hangfire/misfire.
1. After landing - Ensure weapons are
pointed at safe area.
WIRE CUT switch - Press.
9-71. RUNAWAY GUN.
1. MASTER ARM switch - OFF.
2. PLT OVRD switch - OFF.
2. Armament switches - OFF.
3. DC circuit breaker - Out, affected gun.
3. Engine shutdown - Preform.
4. Helicopter - Exit 90°from line of fire.
4. WG ST ARM switch - OFF.
b. Emergency Wire Cut.
Change 15 9-15/(9-16 blank)
TM 55-1520-234-10
APPENDIX A
REFERENCES
AR 70-50
Designating and Naming Military Aircraft, Rockets, and Guided Missiles
AR 95-1
Army Aviation General Provisions and Flight Regulations
AR 95-5
Aircraft Accident Prevention Investigation and Reporting
AR 95-16
Weight and Balance -Army Aircraft
AR 385-40
Accident Reporting and Records
DA PAM 738-751
The Army Maintenance Management System (TAMMS)
FM 1-202
Environmental Flight
FM 1-203
Fundamentals of Flight
FM 1-204
Night Flight Techniques and Procedures
FM 1-230
Meteorology for Army Aviators
FM 1-240
Instrument Flying and Navigation for Army Aviators
FM 10-68
Aircraft Refueling
TB MED 251
Noise and Conservation of Hearing
TM 9-1005-257-12
Operator and Organizational Maintenance: Armament Pod, Aircraft 7.62 MM Gun:
M18A1
TM 9-1090-203-12
Operator and Organizational Maintenance: Armament Subsystem, Helicopter, 7.62
MM Machine Gun - 40 MM Grenade Launcher, M28A1
TM 9-1090-203-12-1
Operator and Organizational Maintenance: Armament Subsystem, Helicopter, Machine Gun - 40MM Grenade Launcher, M28A1E1.
TM 9-1330-208-25
Organizational, Direct Support, General Support, and Depot Maintenance: Dispenser,
Grenade: Smoke XM118
TM 9-1425-473-20
Organizational Maintenance For Armament Subsystem, Helicopter TOW Missile
M65
TM 10-1101
Petroleum Handling Equipment and Operation
TM 55-1500-342-23
Army Aviation Maintenance Engineering Manual - Weight and Balance (formerly
TM 55-405-9)
TM 55-1520-234-CL
Operators and Crewmembers Checklist - AH-1S Helicopter
Change19 A-1
TM 55-1520-234-10
TM 750-244-1-5
Procedures for the Destruction of Aircraft and Associated Equipment to Prevent Enemy Use.
DOD FLIP
DOD Flight Information Publication (Enroute)
FAR Part 91
Federal Aviation Regulation Part 91
Change30 A-2
TM 55-1520-234-10
INDEX
Para.
A
AC Inverter Failure-.....................................................
Caution Light Illumination .............................. 9-36
AC Power Indicators and Controls ....................... 2-60
ADF Set ................................................................ 3-9
After Emergency Action ........................................ 9-4
After Landing ...................................................... 8-28
Air Induction System ........................................... 2-19
Airspeed Calibration....................................................
Description .................................................... 7-39
Use of Chart ................................................. 7-40
Airspeed Indicators .............................................. 2-67
Airspeed Limitations ............................................ 5-13
Allowable Loading ............................................... 6-10
Anti-Collision Light .............................................. 2-62
Appendix A, References ........................................ 1-4
Approved Commercial Fuels, Oils and Fluids ...... 2-79
Area 1 ................................................................. 8-14
Area 2 ................................................................. 8-15
Area 3 .................................................................. 8-16
Area 4 ................................................................. 8-17
Area 5 ................................................................. 8-18
Armament Configuration ....................................... 4-2
Armament Hydraulic System ............................... 2-44
Army Aviation Safety Program .............................. 1-6
Attitude Indicators ............................................... 2-69
Autorotation Characteristics ................................ 8-44
Aviation Life Support Equipment (ALSE) ............... 8-2
Para.
C
Canopy .................................................................... 2-9
Canopy Defrosting, Deicing and Rain
Removal Systems............................................. 2-52
Canopy Door Limitations ........................................ 5-15
Canopy Removal System ....................................... 2-16
Center of Gravity Limitations .................................. 5-10
Chapter 7 Index ....................................................... 7-2
Checklist ................................................................ 8-10
Classification of Helicopter ....................................... 6-2
Climb-Descent
Condition .......................................................... 7-35
Description........................................................ 7-33
Use of Chart ..................................................... 7-34
Clutch Fails to Disengage ....................................... 9-24
Clutch Fails to Re-engage ...................................... 9-25
Cockpit (Map) Lights .............................................. 2-64
Cold Weather Operations ....................................... 8-47
Collective Control System ...................................... 2-31
Control Feedback ................................................... 8-35
Controls and Indicators ........................................... 2-28
Course Indicator ....................................................... 3-6
Crew Briefing ............................................................ 8-4
Crew Compartment Diagrams ................................ 2-12
Crew Duties/Responsibilities .................................... 8-3
Cruise
Conditions ........................................................ 7-29
Description........................................................ 7-27
Use of Charts ................................................... 7-28
Cyclic Control System ............................................ 2-30
D
B
Bailout Procedures .............................................. 9-48
Battery ................................................................ 2-55
Before Exterior Checks ....................................... 8-12
Before Exterior Check-All Armament- .........................
Preflight .......................................................... 4-5
Before Landing .................................................... 8-27
Before Landing Check-All Armament .................. 4-20
Before Leaving Helicopter ................................... 8-30
Before Leaving Helicopter Check-All...........................
Armament ..................................................... 4-21
Before Starting Engine Check ............................. 4-11
Before Starting Engine-Gunner Station ............... 8-20
Before Starting Engine-Pilot Station .................... 8-21
Before Takeoff .................................................... 8-25
Before Takeoff Check-All Armament-Preflight ..... 4-12
Blade Stall .......................................................... 8-34
Danger Areas ........................................................... 8-6
Data Basis................................................................. 7-6
DC and AC Power Distribution ............................... 2-54
DC Generator Failure-DC Generator Caution
Light Illumination .............................................. 9-35
DD Form 365A-Basic Weight Check List ................ 6-11
DD Form 365C-Basic Weight and Balance
Record.............................................................. 6-12
DD Form 365F-Weight and Balance Clearance
Form F ............................................................. 6-13
Definition of Emergency Terms ................................ 9-3
Definitions of Abbreviations .................................... 7-10
Description................................................................ 1-3
Description-Flight Controls ..................................... 2-29
Description-Hydraulic Systems ............................... 2-35
Description-Mission Equipment ................................ 4-3
Desert and Hot Weather Operation ........................ 8-49
Change 19 Index1
TM 55-1520-234-10
INDEX (Cont.)
Para.
D (cont)
Destruction of Army Materiel to Prevent Enemy Use .... 1-7
Ditching-Power Off .........................................................9-44
Ditching-Power On ........................................................9-43
Diving Flight ...................................................................8-36
Drag
Conditions ...............................................................7-32
Description ..............................................................7-30
Use of Chart ............................................................7-31
Driveshafts .....................................................................2-47
Droop Compensator ......................................................2-25
Droop Compensator Failure ..........................................9-15
E
Electrical Circuit .............................................................2-42
Electrical Fire-Flight .......................................................9-30
Electrical System ...........................................................9-34
Electronic Equipment Configuration ................................3-2
Emergency Entrance .......................................................9-5
Emergency Equipment ....................................................9-6
Emergency Hydraulic Control System ..........................2-43
Engine .................................................................... 2-17, 9-9
Engine Compressor Stall................................................9-16
Engine Fire Detection System........................................2-76
Engine Fuel Control System...........................................2-21
Engine Inlet Anti-Icing/Deicing System .........................2-20
Engine Instruments and Indicators.................................2-26
Engine Limitations............................................................5-7
Engine Malfunction-Hover..............................................9-11
Engine Malfunction-Low Altitude/Low Airspeed
or Cruise ..................................................................9-12
Engine Malfunction-Partial or Complete
Power Loss ..............................................................9-10
Engine Malfunction-120 KIAS and Above .....................9-13
Engine Oil Supply System..............................................2-22
Engine Oil Temperature High...................................... 9-18A
Engine Overspeed .........................................................9-18
Engine Protection ..........................................................2-18
Engine Restart-During Flight ..........................................9-14
Engine Runup.................................................................8-23
Engine Shutdown ...........................................................8-29
Environmental Control Unit (ECU).................................2-53
Environmental Restrictions.............................................5-17
Exceeding Operating Limits .......................................... 5-2A
Explanation of Change Symbols....................................1-11
Exterior Check ...............................................................8-13
Exterior Check-Rocket Launcher-Preflight ......................4-8
Exterior Check-Smoke Grenade DispenserPreflight....................................................................4-10
Exterior Check-TOW-Preflight ........................................4-7
Para.
Exterior Check-Turret-Preflight . ....................................4-6
Exterior Check-Wing Gun Pod-Preflight . .......................4-9
External Power Receptacle ...........................................2-57
F
Filter Indicators ..............................................................2-40
Fire .................................................................................9-26
Fire-Engine Start ............................................................9-27
Fire-Flight . .....................................................................9-29
Fire-Ground....................................................................9-28
First-Aid Kit.....................................................................2-15
Flight Control/Main Rotor System Malfunctions ............9-45
FM Command Radio........................................................3-5
Force Trim System.........................................................2-33
Forms and Records..........................................................1-9
Free Air Temperature (FAT) Indicator ...........................2-72
Fuel Data .........................................................................6-8
Fuel Sample Waiting Time ......................................... 2-80A
Fuel Supply System .......................................................2-27
Fuel System Servicing ................................................ 2-78A
Fumes from ECU ..........................................................9-31
Fuselage ..........................................................................2-5
G
Gearboxes .....................................................................2-46
General ............................................................................1-1
General-Adverse Environmental Conditions .................8-46
General Arrangement.......................................................2-2
General-Avionics..............................................................3-1
General Conditions...........................................................7-8
General Description..........................................................2-1
General-Performance Data .............................................7-3
General-operating Limits and Restrictions ......................5-2
General-Weight/Balance and Loading ............................6-1
Governor RPM Switches................................................2-24
Gun Camera.....................................................................4-1
Gunner Electrical Power Control ...................................2-58
Gunner Station Lighting .................................................2-66
Gyro-magnetic Compass Set ........................................3-10
H
Helicopter Designation System .....................................1-12
Helicopter Station Diagram .............................................6-3
Helicopter Systems ..........................................................9-1
Hover
Conditions ...............................................................7-20
Control Margin ..................................................... 7-19A
Description ..............................................................7-18
Use of Chart ............................................................7-19
Hover Check ..................................................................8-24
Change 30 Index 2
TM 55-1520-234-10
INDEX (Cont.)
Para.
H (cont)
Hydraulic Failure - Dual System.....................................9-40
Hydraulic Failure-Single System....................................9-39
Hydraulic System Failure ...............................................9-38
Hydraulic System No. 1..................................................2-36
Hydraulic System No. 2..................................................2-37
I
Icing Conditions .............................................................8-51
Idle Fuel Flow
Condition .................................................................7-37
Description ..............................................................7-36
Use of Chart.............................................................7-38
Ignition Starter System ..................................................2-23
Immediate Action Emergency Steps ...............................9-2
Index ................................................................................1-5
Indicators and Caution Lights ........................................2-48
Inflight Procedures-All Armament .................................4-13
Inflight Wire Strike .........................................................9-49
Inlet Guide Vane Actuator Failure .................................9-17
Instrument Flight Procedures ........................................8-31
Instrument Markings ........................................................5-4
Instruments and Controls ...............................................2-13
J
K
L
Landing and Ditching .....................................................9-41
Landing Gear ...................................................................2-8
Landing in Trees ............................................................9-42
Limits ...............................................................................7-4
Loading Charts ................................................................6-4
Low G Maneuvers ..........................................................8-41
Low G Warning ........................................................... 9-45A
Low Pressure Caution Lights .........................................2-41
S
Magnetic (Standby) Compass .......................................2-73
Main Driveshaft Failure .................................................9-22
Main Rotor .....................................................................2-49
Maneuvering Flight ........................................................8-40
Mast Bumping ..................................................... 8-45, 9-46
Master Caution System .................................................2-75
Maximum Glide Distance.................................................9-8
Maximum Performance..................................................8-26
Minimum Crew Requirements .........................................5-3
Minimum Rate of Descent................................................9-7
Mission Equipment Checks .............................................8-8
Mission Planning .............................................................8-1
Para.
N
O
Oil Data ...........................................................................6-9
Operating Characteristics ..............................................8-32
Operating Procedures and Maneuvers ............................8-7
Overheated Battery .......................................................9-37
P
Passenger Briefing ..........................................................8-5
Performance Discrepancies ............................................7-9
Performance Planning ...................................................7-11
Personnel Doors ............................................................2-10
Personnel Moments .........................................................6-6
Pilot DC Power Indicators and Controls ........................2-59
Pilot Station Lighting.......................................................2-65
Pitch Cone Coupling.......................................................8-38
Pitot Tube Heater ...........................................................2-51
Portable Fire Extinguisher .............................................2-14
Position Lights ................................................................2-61
Power Dives ...................................................................8-37
Preflight Check...............................................................8-11
Preflight Procedures.........................................................4-4
Pressure Altimeters ........................................................2-68
Principal Dimensions........................................................2-3
Prohibited Maneuvers ....................................................5-16
Purpose-Operating Limits and Restrictions .....................5-1
Purpose-Performance Data .............................................7-1
Q
R
Radar Warning System AN/APR-39(V-1) .....................3-12
Radio Aids to Navigation ...............................................2-74
Rain ...............................................................................8-52
Reservoir Fluid Sight Glasses .......................................2-39
Rocket Operation-Inflight Procedures ...........................4-16
Rollover Characteristics ................................................8-33
Rotor Limitations .............................................................5-5
Rotor RPM-Power Off ....................................................8-43
Rotors, Transmission, and Drive Systems.....................9-19
RPM High-Low Limit Warning System...........................2-77
Runaway Gun ................................................................9-52
S
Searchlight .....................................................................2-63
Seats-Pilot and Gunner..................................................2-11
Servicing ........................................................................2-78
Change 30 Index 3
TM 55-1520-234-10
INDEX (Cont.)
Para.
S
Settling with Power ........................................................8-42
Signal Distribution Panel .................................................3-3
Single or Dual Fuel Boost Pump Failure .......................9-33
Smoke and Fume Elimination .......................................9-32
Smoke Grenade Dispenser OperationInflight Procedures ..................................................4-18
Snow ..............................................................................8-48
Specific Conditions ..........................................................7-7
Stability and Control Augmentation System
(SCAS).....................................................................2-34
Stability and Control Augmentation System
(SCAS) Failure .......................................................9-47
Starter-Generator ...........................................................2-56
Starting Engine ..............................................................8-22
Symbols Definition ...........................................................8-9
T
Tail Rotor .......................................................................2-50
Tail Rotor Control System .............................................2-32
Tail Rotor Failure-Flight .................................................9-20
Tail Rotor Failure-Hover ................................................9-21
Tailboom...........................................................................2-6
Takeoff
Conditions................................................................7-23
Description...............................................................7-21
Use of Chart ............................................................7-22
Temperature Conversion ...............................................7-12
Test Switch.....................................................................2-38
Torque Available
Chart Differences ....................................................7-15
Conditions................................................................7-17
Description ..............................................................7-14
Use of Chart ............................................................7-16
TOW Missile Emergency Procedures ...........................9-51
TOW Operation-Inflight Procedures ..............................4-15
Transient Torque ...........................................................8-39
Para.
Transmission ..................................................................245
Transmission Sprag Clutch Malfunction ........................9-23
Transponder Set AN/APX-72 ........................................3-11
Turbulence and Thunderstorms ....................................8-50
Turbulence Restrictions .............................................. 5-10A
Turn and Slip Indicator ..................................................2-70
Turning Radius ................................................................2-4
Turret Operation-Inflight Procedures .............................4-14
Types and Use of Fuel ...................................................2-80
U
UHF Command Set..........................................................3-4
Use of Charts....................................................................7-5
V
Vertical Velocity Indicator ..............................................2-71
VHF Radio Set ................................................................3-8
Voice Security Equipment................................................3-7
W
Walk-Around Check ......................................................8-19
Warnings, Cautions, and Notes Definition ......................1-2
Weight and Balance Loading Data ..................................6-7
Weight and Balance Records ..........................................6-5
Weight Limitations..........................................................5-11
Wing ................................................................................2-7
Wing Gun Pod Operation-Inflight Procedures ...............4-17
Wing Stores Emergency Jettison ..................................9-50
Wing Stores Jettison-Inflight Procedures ......................4-19
X
Y
Z
U.S. GOVERNMENT PRINTING OFFICE: 1992 - 654 - 12260022
PIN: 014865-030
Change 19 Index 4
TM 55-1520-234-10
Fig./Para.
Fig./Para.
Hover Check ..................................................................8-28
Hovering Capability .......................................................8-71
Hovering Flight - Sideward and
Rearward ................................................................8-26
Hovering Limitations ........................................................5-9
Hovering Turns ..............................................................8-25
Hydraulic Control System - Emergency ....................... 2-43
Hydraulic System - Armament ..................................... 2-44
Hydraulic System Failure ............................................. 9-57
Hydraulic Systems .........................................................2-35
Landing Gear ...................................................................2-8
Landing in Trees ............................................................9-63
Leaving Helicopter -Before ............................................8-49
Leaving Helicopter Check - Armament
Before .....................................................................4-21
Level Acceleration .........................................................8-35
Level Flight Characteristic .............................................8-74
Light - Caution - Engine Chip
Detector ..................................................................9-22
Light - Chip Detector - XMSN, 90°, 42°.........................9-29
Light - Collision ..............................................................2-62
Light - Search ................................................................2-63
Lighting -Gunner Station ...............................................2-66
Lighting - Pilot Station ...................................................2-65
Lights - Cockpit (Map) ...................................................2-64
Lights - Position .............................................................2-61
Lights Control Panel - Pilot ......................................... F2-17
Limitations - Airspeed ....................................................5-13
Limitations - Canopy Door .............................................5-15
Limitations - Center of Gravity ......................................5-10
Limitations - Engine .........................................................5-7
Limitations - Hovering .....................................................5-9
Limitations - Rotor ...........................................................5-5
Limits - Exceeding Operating ..........................................5-2
Limits and Restrictions - Operating .................................8-2
Loading - Allowable, Weight/Balance ............................6-10
Loading - Weight/Balance ...............................................6-7
Loading - Weight/Balance ...............................................8-3
Loading and Weight/Balance General .....................................................................6-1
Loading Chart ..................................................................6-4
Loading Configurations - Armament ............................4-2.a
Low Altitude - Engine Fire .............................................9-39
Low "G" Maneuvers .......................................................8-70
I
Icing Conditions .............................................................8-81
Ignition - Starter System ................................................2-23
Immediate Action Emergency Checks ............................9-2
Indicator - Course ............................................................3-6
Induction System - Air ...................................................2-19
Inflight Procedures - Armament ....................................4-13
Inlet, Anti-Icing/Deicing SystemEngine .....................................................................2-20
Inlet Guide Vane Actuator Failure .................................9-21
Instrument - Holding ......................................................8-56
Instrument Approaches .................................................8-57
Instrument Autorotation .................................................8-55
Instrument Climb ...........................................................8-52
Instrument Cruise ..........................................................8-53
Instrument Descent .......................................................8-54
Instrument Flight Procedures ........................................8-50
Instrument Markings ........................................................5-4
Instrument Panel - Gunner .........................................2-13.b
Instrument Panel - Pilot ..............................................2-13.a
Instrument Takeoff ........................................................8-51
Interior Check - Gunner .................................................8-19
Internal Engine Fire During Start ...................................9-34
Interphone Receptacles - External ...............................3-2.c
Inverter Failure - AC ......................................................9-56
M
Main Rotor .....................................................................2-49
Main Rotor - Area 1 - Fuselage .....................................8-14
Maneuvering Flight.........................................................8-69
Maneuvers - Low "G" ....................................................8-70
Maneuvers - Operating Procedures ................................8-8
Maneuvers - Prohibited .................................................5-16
Map (Cockpit) Lights ......................................................2-64
Margin - Safe Pedal .......................................................5-14
Markings - Instrument ......................................................5-4
Mast Bumping ...............................................................9-31
Master Caution System .................................................2-75
Maximum Glide Distance - Power
Off ...........................................................................9-12
Maximum Performance Takeoff ...................................8-33
Minimum Crew Requirements .........................................5-3
J
Jettison - Wing Stores Emergency ................................9-69
Jettison Description - Wing Stores ......................... 4-3.a.(6)
Jettison Switch - Gunner Wing
Stores ............................................................... 4-3.c.(5)
K
L
Landing - After ...............................................................8-47
Landing - Before ............................................................8-41
Landing - Running .........................................................8-46
Landing Check - Armament Before ...............................4-20
Landing From a Hover ..................................................8-29
Index 5
TM 55-1520-234-10
Fig./Para.
Fig./Para.
Minimum Rate of Descent - Power
Off ...........................................................................9-11
Miscellaneous Control Panel Gunner ................................................................. F2-10
Miscellaneous Control Panel - Pilot ............................ F2-11
Missile Emergency Procedures TOW .......................................................................9-70
Missile Status Panel (MSP) - Pilot .......................... 4-3.b.(8)
Mission Planning .............................................................8-1
Moments - Personnel ......................................................6-6
Mooring Diagram ...........................................................2-81
Plan-Flight .......................................................................8-5
Planning - Mission ...........................................................8-1
Pod Description - Wing Gun ................................... 4-3.a.(4)
Pod Exterior Check - Wing Gun ......................................4-9
Pod Operation - Wing Gun ............................................4-17
Position Lights ...............................................................2-61
Power - Settling With .....................................................8-72
Power Control - Gunner Electrical .................................2-58
Power Distribution - AC and DC ....................................2-54
Power Dives ..................................................................8-66
Power Indicators and Controls Pilot AC ...................................................................2-60
Power Indicators and Controls Pilot DC ..................................................................2-59
Power Off - Maximum Glide Distance ..........................9-12
Power Off - Minimum Rate of Descent .........................9-11
Power Off - Rotor RPM .................................................8-73
Power Off Ditching ........................................................9-65
Power On Ditching ........................................................9-64
Power Panel - Pilot Electrical ..................................... F2-15
Power Receptacle - External .........................................2-57
Power Supply (Radio) ...................................................3-2.d
Preflight Procedures ........................................................4-4
Principal Dimensions - Helicopter ...................................2-3
Procedure - TOW Missile Emergency ..........................9-70
Procedures - Instrument Flight ......................................8-50
Procedures and Maneuvers - Operating ..........................8-8
Procedures Bailout ........................................................9-68
Prohibited Maneuvers ...................................................5-16
Pump Failure - Engine Driven Fuel ...............................9-25
Pump Failure Fuel Boost .............................................9-49
N
N2 Governor - Engine Overspeed .................................9-17
N2 Governor - Engine Underspeed ...............................9-18
Navigation - Radio Aids to .............................................2-74
Night Flying ....................................................................8-58
Ninety Degree Gearbox Chip Detector
Light ........................................................................9-29
Normal Approach - Landing ..........................................8-43
Normal Takeoff ..............................................................8-32
Nose Section - Area 5 ...................................................8-18
O
Object Damage Screen - Foreign ..............................2-19.a
Oil - Weight/Balance .......................................................6-9
Oil Supply Failure - Engine ............................................9-24
Oil Supply System - Engine ..........................................2-22
Oil System Failure - Transmission ................................9-30
Oils - Commercial .......................................................2-79.b
Oils, Fluids, and Fuels - Military .................................2-78.b
Operating Characteristics ..............................................8-59
Operating Limits - Exceeding ..........................................5-2
Operating Limits and Restrictions ....................................8-2
Operating Procedures and Maneuvers ...........................8-8
Operation - Cold Weather .............................................8-77
Operation - Desert and Hot Weather .............................8-79
Overspeed - Engine - N2 Governor .............................9317
Q
R
Radio - ADF Set ..............................................................3-9
Radio - FM Command .....................................................3-5
Radio - Power Supply ...................................................3-2.d
Radio - UHF Command Set ............................................3-4
Radio - VHF Set ..............................................................3-8
Radio Aids to Navigation ...............................................2-74
Radius - Turning ..............................................................2-3
Rate of Descent -Minimum-Power Off ..........................9-11
Rating - Engine ................................................................5-8
Rearward Hovering Flight - Sideward ...........................8-26
Receptacle - External Power .........................................2-57
Recognition - Rotor Stall ...............................................8-62
Reduction - Rotor Stall ..................................................8-63
Reflex Sight - Pilot ................................................ 4-3.b.(10)
Removal System - Canopy ...........................................2-16
Requirements - Minimum Crew ......................................5-3
Restart - During Flight - Engine .....................................9-16
P
Panel - Signal Distribution ...............................................3-3
Particle Separator .......................................................2-19.b
Pedal Margin - Safe .......................................................5-14
Performance ....................................................................8-4
Personnel Moments .........................................................6-6
Pilot Station ................................................................2-12.a
Pilot Steering Indicator (PSI) .................................. 4-3.b.(7)
Pilot Technique ..............................................................8-76
Pitch Cone Coupling ......................................................8-67
Pitot Tube ......................................................................2-51
Index 6
TM 55-1520-234-10
Fig./Para.
Fig./Para.
Smoke Grenade Dispenser Description ................. 4-3.a.(5)
Smoke Grenade Dispenser Exterior
Check ......................................................................4-10
Smoke Grenade Dispenser Operation ..........................4-18
Smoke Grenade Release Switch -Pilot .................. 4-3.b.(4)
Snow ..............................................................................8-78
Stability and Control Augmentation
System (SCAS) ......................................................2-34
Stability and Control Augmentation System ..................9-67
Stall - Engine Compressor ............................................9-20
Stall - Rotor Blade .........................................................8-61
Stall Recognition - Rotor ...............................................8-62
Stall Reduction - Rotor ..................................................8-63
Start - Emergency ...........................................................9-9
Start - Engine Fire During - Internal
or Torching ..............................................................9-34
Start - Hot - Emergency Shutdown ................................9-35
Starter - Generator ........................................................2-56
Starter - Ignition System ................................................2-23
Starting Engine ..............................................................8-22
Starting Engine - Gunner - Before .................................8-20
Starting Engine - Pilot - Before ......................................8-21
Starting Engine Check - Armament
Before .....................................................................4-11
Station - Gunner .........................................................2-12.b
Station - Pilot ..............................................................2-12.a
Station Diagram - Weight/Balance ..................................6-3
Station Lighting - Gunner ..............................................2-66
Station Lighting - Pilot ...................................................2-65
Status Panel (MSP) - Pilot Missile .......................... 4-3.b.(8)
Steep Approach - Landing .............................................8-44
Steering Indicator - Pilot ......................................... 4-3.b.(7)
Stores Control Panel - Pilot Wing ........................... 4-3.b.(2)
Stores Emergency Jettison - Wing ................................9-69
Stores Fire - Wing - Flight .............................................9-45
Stores Jettison Description - Wing ......................... 4-3.a.(6)
Stores Jettison Switch - Gunner
Wing .................................................................4-3.c.(5)
Stores Jettison Switch - Pilot Wing ........................ 4-3.b.(5)
System Failure - Hydraulic ............................................9-57
Systems - Helicopter .......................................................9-1
Restrictions - Environmental .........................................5-17
Restrictions - Operating Limits ........................................8-2
Rocket Exterior Check .....................................................4-8
Rocket Operation ...........................................................4-16
Rockets Description................................................. 4-3.a.(3)
Rollover Characteristics .................................................8-60
Rotor - Main ...................................................................2-49
Rotor - Tail .....................................................................2-50
Rotor Blade Stall ............................................................8-61
Rotor Control System - Tail ...........................................2-31
Rotor Failure - Tail Inflight .............................................9-27
Rotor Limitations ..............................................................5-5
Rotor RPM - Power Off .................................................8-73
Rotor Stall - Recognition ................................................8-62
Rotor Stall - Reduction ..................................................8-63
Rotor Tiedowns ..............................................................2-81
RPM - Rotor - Power Off ...............................................8-73
RPM High-Low Limit Warning System ..........................2-77
Runaway Gun ................................................................9-71
Funning Landing ............................................................8-46
Recoup - Engine ............................................................8-23
S
Safe Pedal Margin .........................................................5-14
SCAS Control Panel - Pilot ......................................... F2-12
Screen - Foreign Object Damage ..............................2-19.a
Searchlight .....................................................................2-63
Seats ..............................................................................2-11
Security Equipment - Voice .............................................3-7
Separator - Particle .....................................................2-19.b
Servicing ........................................................................2-78
Settling with Power ........................................................8-72
Shaft - Engine Drive/Clutch Failure ...............................9-15
Shallow Approach - Landing ..........................................8-45
Shutdown - Emergency - Electrical Failure....................9-54
Shutdown - Emergency - Hot Start ................................9-35
Shutdown - Emergency - Throttle Failure ......................9-52
Shutdown - Engine ........................................................8-48
Sideward and Rearward Hovering Flight .......................8-26
Sight - Gunner Helmet ............................................ 4-3.c.(2)
Sight - Pilot Helmet ............................................... 4-3.b.(11)
Sight - Pilot Reflex ................................................ 4-3.b.(10)
Sight Hand Control (SHC) - Gunner ....................... 4-3.c.(6)
Sight Subsystem (HSS) Description Helmet ............................................................. 4-3.a.(7)
Sight Unit (TSU) - Gunner
Telescopic ........................................................ 4-3.c.(3)
Signal Distribution Panel .................................................3-3
Smoke and Fume Elimination .......................................9-46
Smoke Grenade Dispenser Control
Panel - Pilot ..................................................... 4-3.b.(3)
T
Tail Rotor .......................................................................2-50
Tail Rotor Control System .............................................2-31
Tail Rotor Failure - Inflight .............................................9-27
Tail Section - Left Side - Area 3 ....................................8-16
Tail Section - Right Side - Area 2 ..................................8-15
Tailboom ..........................................................................2-6
Takeoff ..........................................................................8-31
Takeoff - Before ............................................................8-30
Index 7
TM 55-1520-234-10
Fig./Para.
V
Velocity Diagram - Height .............................................5-18
Vertical Velocity Indicator ..............................................2-71
VHF Radio Set ................................................................3-8
Voice Security Equipment ...............................................3-7
Fig./Para.
Takeoff - Crosswind .......................................................8-37
Takeoff - Maximum Performance .................................8-33
Takeoff - Normal ...........................................................8-32
Takeoff Check - Armament Before ...............................4-12
Takeoff Instrument ........................................................8-51
Takeoff to Hover ............................................................8-24
Taxi - Hover ...................................................................8-27
Technique - Pilot ............................................................8-76
Techniques - Comparison of .........................................8-36
Telescopic Sight Unit (TSU) - Gunner .................... 4-3.c.(3)
Throttle Failure - Emergency Shutdown.........................9-52
Thunderstorms and Turbulence ....................................8-80
Tiedowns - Rotor ...........................................................2-80
Torching - Engine Fire During Start ...............................9-34
Torque - Transient .........................................................8-68
TOW Control Panel (TCP) - Gunner ...................... 4-3.c.(7)
TOW Exterior Check .......................................................4-7
TOW Missile Description ........................................ 4-3.a.(2)
TOW Missile Emergency Procedures ...........................9-70
TOW Operation .............................................................4-15
Transient Torque ...........................................................8-68
Transmission .................................................................2-45
Transmission Chip Detector Light .................................9-29
Transmission Indicators .................................................2-48
Transmission Oil System Failure ..................................9-31
Transponder Set ............................................................3-11
Trees - Landing in ..........................................................9-63
Trim System - Force ......................................................2-31
Tube - Pitot ....................................................................2-51
Turbulence and Thunderstorms ....................................8-80
Turn and Slip Indicator ..................................................2-70
Turning Radius ................................................................2-3
Turns - Hovering ............................................................8-25
Turret - Exterior Check ....................................................4-6
Turret Description ................................................... 4-3.a.(1)
Turret Operation ............................................................4-14
W
Warning System - RPM High-Low Limit .......................2-77
Weather Operation - Cold .............................................8-77
Weather Operation - Desert and Hot ............................8-79
Weight/Balance - Allowable Loading .............................6-10
Weight/Balance - Fuel .....................................................6-8
Weight/Balance - Loading ...............................................6-7
Weight/Balance - Oil .......................................................6-9
Weight/Balance - Personnel ............................................6-6
Weight/Balance and Loading ..........................................8-3
Weight/Balance and Loading - General ..........................6-1
Weight/Balance Clearance Form F DD Form 365F ........................................................6-13
Weight/Balance Record - DD Form 365C .....................6-12
Weight/Balance Records .................................................6-5
Weight/Balance Station Diagram ....................................6-3
Weight Check List - DD Form 365A Basic ....................6-11
Wing ................................................................................2-7
Wing Gun Pod Exterior Check ........................................4-9
Wing Gun Pod Description ..................................... 4-3.a.(4)
Wing Gun Pod Operation ..............................................4-17
Wing Stores Control Panel - Pilot ........................... 4-3.b.(2)
Wing Stores Emergency Jettison ..................................9-69
Wing Stores Fire - Flight ...............................................9-45
Wing Stores Jettison Description ........................... 4-3.a.(6)
Wing Stores Jettison Switch - Gunner ....................4-3.c.(5)
Wing Stores Jettison Switch - Pilot ........................ 4-3.b.(5)
X
Y
U
UHF Command Set .........................................................3-4
Underspeed - Engine - N2 Governor .............................9-18
Unit - Environmental Control .........................................2-53
Z
U.S. GOVERNMENT PRINTING OFFICE : 1990 0 - 262-842 (25167)
Index 8
The Metric System and Equivalents
Linear Measure
Liquid Measure
1 centiliter = 10 milliters = .34 fl. ounce
1 deciliter = 10 centiliters = 3.38 fl. ounces
1 liter = 10 deciliters = 33.81 fl. ounces
1 dekaliter = 10 liters = 2.64 gallons
1 hectoliter = 10 dekaliters = 26.42 gallons
1 kiloliter = 10 hectoliters = 264.18 gallons
1 centimeter = 10 millimeters = .39 inch
1 decimeter = 10 centimeters = 3.94 inches
1 meter = 10 decimeters = 39.37 inches
1 dekameter = 10 meters = 32.8 feet
1 hectometer = 10 dekameters = 328.08 feet
1 kilometer = 10 hectometers = 3,280.8 feet
Square Measure
Weights
1 sq. centimeter = 100 sq. millimeters = .155 sq. inch
1 sq. decimeter = 100 sq. centimeters = 15.5 sq. inches
1 sq. meter (centare) = 100 sq. decimeters = 10.76 sq. feet
1 sq. dekameter (are) = 100 sq. meters = 1,076.4 sq. feet
1 sq. hectometer (hectare) = 100 sq. dekameters = 2.47 acres
1 sq. kilometer = 100 sq. hectometers = .386 sq. mile
1 centigram = 10 milligrams = .15 grain
1 decigram = 10 centigrams = 1.54 grains
1 gram = 10 decigram = .035 ounce
1 decagram = 10 grams = .35 ounce
1 hectogram = 10 decagrams = 3.52 ounces
1 kilogram = 10 hectograms = 2.2 pounds
1 quintal = 100 kilograms = 220.46 pounds
1 metric ton = 10 quintals = 1.1 short tons
Cubic Measure
1 cu. centimeter = 1000 cu. millimeters = .06 cu. inch
1 cu. decimeter = 1000 cu. centimeters = 61.02 cu. inches
1 cu. meter = 1000 cu. decimeters = 35.31 cu. feet
Approximate Conversion Factors
To change
To
inches
feet
yards
miles
square inches
square feet
square yards
square miles
acres
cubic feet
cubic yards
fluid ounces
pints
quarts
gallons
ounces
pounds
short tons
pound-feet
pound-inches
centimeters
meters
meters
kilometers
square centimeters
square meters
square meters
square kilometers
square hectometers
cubic meters
cubic meters
milliliters
liters
liters
liters
grams
kilograms
metric tons
Newton-meters
Newton-meters
Multiply by
To change
2.540
.305
.914
1.609
6.451
.093
.836
2.590
.405
.028
.765
29,573
.473
.946
3.785
28.349
.454
.907
1.356
.11296
ounce-inches
centimeters
meters
meters
kilometers
square centimeters
square meters
square meters
square kilometers
square hectometers
cubic meters
cubic meters
milliliters
liters
liters
liters
grams
kilograms
metric tons
To
Newton-meters
inches
feet
yards
miles
square inches
square feet
square yards
square miles
acres
cubic feet
cubic yards
fluid ounces
pints
quarts
gallons
ounces
pounds
short tons
Temperature (Exact)
°F
Fahrenheit
temperature
5/9 (after
subtracting 32)
Celsius
temperature
°C
Multiply by
.007062
.394
3.280
1.094
.621
.155
10.764
1.196
.386
2.471
35.315
1.308
.034
2.113
1.057
.264
.035
2.205
1.102
PIN: 014865-000
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