OH-58A
TECHNICAL MANUAL
OPERATORS, AVIATION UNIT,
AND AVIATION
INTERMEDIATE MAINTENANCE
CHAPTER 1. GENERAL INFORMATION
CHAPTER 2. ASSESSING BATTLEFIELD DAMAGE
CHAPTER 3. GENERAL REPAIR
CHAPTER 4. AIRFRAME
TM 55-1520-228-BD
FOR
HELlCOPTER,
OBSERVATION
OH-58A & OH-58C
ITEM NSN
INSIDE FRONT COVER
This publication supersedes
TM 55-1520-228-BD dated
17 August 1990.
CHAPTER 5. ALIGHTING GEAR
CHAPTER 6. POWER PLANT
CHAPTER 7. ROTORS
CHAPTER 8. DRIVE TRAIN SYSTEM
CHAPTER 9. HYDRAULIC SYSTEM
CHAPTER 10: INSTRUMENT SYSTEMS
CHAPTER 11. ELECTRICAL SYSTEM
CHAPTER 12. FUEL SYSTEM
CHAPTER 13. FLIGHT CONTROLS
CHAPTER 14. UTILITY SYSTEM
CHAPTER 15. ENVIRONMENTAL CONTROL SYSTEM
CHAPTER 16. MISSION EQUIPMENT
CHAPTER 17. EMERGENCY EQUIPMENT
APPENDIX A . REFERENCES
APPENDIX B. SPECIAL OR FABRICATED TOOLS
APPENDIX C. EXPENDABLE/DURABLE SUPPLIES
& MATERIALS
APPENDIX D. SUBSTITUTE MATERIALS/PARTS
APPENDIX E. BDAR TRAINING PROCEDURES
APPENDIX F. AVIONICS CONFIGURATIONS
HEADQUARTERS, DEPARTMENT OF THE ARMY
4 January 1991
TM 55-1520-228-BD
AND SHALL BE REPAIRED BY STANDARD MAINTENANCE PROCEDURES
AS SOON AS PRACTICABLE AFTER THE MISSION IS COMPLETED.
BDAR FIXES SHALL BE USED ONLY IN COMBAT
AT THE DISCRETION OF THE COMMANDER
BDAR TECHNIQUES
OH-58A
OH-58C
Helicopter, Observation
Helicopter, Observation
IN THIS
MANUAL PERTAIN to the following helicopters:
NSN 1520-00-169-7137
NSN 1520-01-020-4216
TM 55-1520-228-BD
WARNING DATA
Personnel performing operations, procedures, and practices which are included or
implied in this technical manual shall observe the general following warnings.
Disregard of these warnings can cause serious injury or death.
WARNINGS
FLIGHT SAFETY
The standards contained herein allow aircraft to be flown with battle damage
substantially in excess of peacetime limits. Under no circumstances shall this
manual be used entirely or in part for peacetime maintenance of the aircraft.
Assessment of aircraft battle damage requires extreme care and diligence and strict
adherence to the instructions and standards contained in this manual. If at any
stage of damage assessment the assessor believes that oversights or errors have
been made, the assessment shall be stopped at that point and repeated from the
beginning.
Under no circumstances shall the requirements of this manual be waived
or circumvented without the express approval of the commander or his designated
representative.
EXPLOSIVES
Battle damaged areas should be inspected for unexploded ordnance before attempting
repairs. Disposal of unexploded ordnance should be accomplished by qualified
personnel.
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 accidental
firing.
Personnel shall remain clear of hazardous area.
CLEANING SOLVENTS
Cleaning solvents may be flammable and toxic. Use only in well-ventilated areas.
Avoid inhalation of vapor and skin contact. Do not use solvents near open flame or
in areas where very high temperatures prevail. Solvent flash point must not be less
than 100°F.
COMPRESSED AIR
Compressed air can blow dust into eyes. Wear eye protection. Do not exceed 30 psig
air pressure.
ELECTROLYTE
Battery Electrolyte (Potassium Hydroxide) is corrosive. Wear rubber gloves, apron,
and face shield when handling leaking batteries. 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
washing until medical assistance arrives.
a
TM 55-1520-228-BD
HIGH VOLTAGE
is used in this equipment.
DEATH ON CONTACT
may result if personnel fail to observe safety precautions.
Never work on electronic equipment unless there is another person nearby who is
familiar with the operation and hazards of the equipment and who is competent in
administering first aid. When the technician is aided by operators, he must warn
them about dangerous areas.
Whenever the nature of the operation permits, keep one hand away from the equipment
as to reduce the hazard of current flowing through vital organs of the body.
Do not be mislead by the term “low voltage.” Potentials as low as 50 volts may
cause death under adverse conditions. For Artificial Respiration, refer to FM 21-11.
b
TM 55-1520-228-BD
EXTERNAL STORES
Prior to any helicopter maintenance functions that require external stores be
removed, JETTISON cartridge shall be removed. To prevent injury to personnel
and damage to equipment, remove jettison cartridges from stores ejection device
prior to placing helicopter in a hangar.
All ground safety pins must be removed before flight.
Failure to do so will prevent
emergency jettison of stores.
FIRE EXTINGUISHER
Exposure to high concentrations of monobromotrifluoromethane (CF
agent or decomposition products should be avoided.
The liquid should not be allowed
3BR) extinguishing
to come into contact with the skin, as it may cause frost bite or low temperature
burns.
FUELING AND FUEL REPAIRS
When refueling helicopter,
the refueling vehicle must be parked a minimum of 20 feet
from the helicopter. Before starting the fueling operation, always insert fueling
nozzle grounding cable of fuel truck into GROUND HERE receptacle.
10-68. When defueling,
power from the helicopter.
turn off all electrical switches and disconnect external
The helicopter must be electrically grounded prior to
Refer to FM
defueling.
Fuel line and tank repairs often involve handling of highly flammable material.
Mishandling can result in serious injury or death.
GROUNDING HELICOPTER
The helicopter should be electrically grounded when parked to dissipate static
electricity.
Turn off all power switches before making electrical connections or
disconnections.
HIGH PRESSURE
Extremely high pressure can occur during and after operation of certain equipment.
If this pressure is not relieved before working on this equipment, serious injury or
death may occur.
Be sure to open all drains and vents before beginning disassembly.
HYDRAULIC FLUID
Prolonged contact with liquid or mist can irritate eyes and skin. Wear rubber
gloves when handling liquid. After contact with skin, inmmediately wash contacted
area with soap and water. If liquid contacts eyes,
flush immediately with clear
water. If liquid is swallowed, do not induce vomiting, get immediate medical atten-
tion. If prolonged exposure with mist is likely, wear an appropriate respirator.
When fluid is decomposed by heating, toxic gases are released.
c
TM 55-1520-228-BD
LIFTING
Lifting or moving heavy equipment incorrectly can cause serious injury. Do not try
to lift or move more than 50 pounds by yourself. Bend legs while lifting. D
support heavy weight with your back.
tions.
Use guide ropes to move hanging assemblies.
Always use assistants during lifting opera-
Lack of attention or being in
an improper position during lifting operations can result in serious injury.
close attention to movements of assemblies being lifted.
Do not stand under lifted
O
not
Pay
assembly or in a position where you could be pinned against another object. Watch
your footing.
NOISE
Sound pressure levels in and around this aircraft during operating conditions exceed
the Surgeon General’s hearing conservation criteria, as defined in TB MED 501.
Hearing protection devices such as aviator helmet or ear plugs are required to be
worn.
RADIOACTIVE MATERIALS
Self-luminous dials and ignition units may contain radioactive materials. If such
an instrument or unit is broken or becomes unsealed, avoid personal contact. Use
forceps or gloves made of rubber or polyethylene to pick up contaminated material.
Place materials and gloves in a plastic bag.
Seal bag and dispose of it as radio-
active waste in accordance with AR 708-1 and TM 3-261 (Refer to TB 43-0108). Repair
shall conform to requirements in AR 385-11.
SANDING DUST
Sanding on reinforced laminated glass produces fine dust that may cause skin
and lung irritations.
Observe necessary protective measures.
STARTING HELICOPTER
Starting and operation of the helicopter will be performed only by authorized
personnel.
TOXIC POISONS
Turbine fuels, lubricating oils,
and readily absorbed through the skin.
than necessary.
Wear protective equipment.
and adhesives contain additives which are poisonous
Do not allow them to remain on skin longer
d
TM 55-1520-228-BD
C 1
CHANGE HEADQUARTERS
DEPARTMENT OF THE ARMY
NO. 1 WASHINGTON, D.C., 1 September 2005
TECHNICAL MANUAL
OPERATORS, AVIATION UNIT, AND AVIATION INTERMEDIATE
MAINTENANCE
BATTLEFIELD DAMAGE ASSESSMENT AND REPAIR
FOR HELICOPTER, OBSERVATION OH-58A & OH-58C
DISTRIBUTION STATEMENT A:
TM 55-1520-228-BD, dated 4 January 1991, 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/(B blank)
i and ii i and ii
1-5 and 1-6 1-5 and 1-6
Approved for public release; distribution is unlimited.
2. Retain this sheet in front of manual for reference purposes.
By Order of the Secretary of the Army:
Official:
SANDRA R. RILEY
Administrative Assistant to the
Secretary of the Army
0518801
PETER J. SCHOOMAKER
General, United States Army
Chief of Staff
DISTRIBUTION:
To be distributed in accordance with Initial Distribution Number (IDN) 311704, requirements for
TM 55-1520-228-BD.
TM 55-1520-228-BD
LIST OF EFFECTIVE PAGES
Insert latest changed pages. Dispose of superseded pages in accordance with regulations.
NOTE: On a changed page, the portion of the text affected by the latest change is indicated by a vertical
line, or other change symbol, in the outer margin of the page. Changes to illustrations are indicated by
miniature pointing hands. Changes to wiring diagrams are indicated by shaded areas.
Dates of issue for original and changed pages are:
Original………… 4 January 1991 Change 1……… 1 September 2005
TOTAL NUMBER OF PAGES IN THIS PUBLICATION IS 762. CONSISTING OF THE FOLLOWING:
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Change 1 A/(B blank)
TM 55-1520-228-BD
Technical Manual
HEADQUARTERS
DEPARTMENT OF THE ARMY
No. 55-1520-228-BD
WASHINGTON, D.C., 4 January 1991
TECHNICAL MANUAL
OPERATORS, AVIATION UNIT, AND AVIATION INTERMEDIATE MAINTENANCE
BATTLEFIELD DAMAGE ASSESSMENT AND REPAIR
FOR HELICOPTER, OBSERVATION OH-58A & OH-58C
REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS
You can help improve this manual. If you find any mistakes, or if you know of a way to improve these procedures, please let us
know. Mail your letter or DA Form 2028 (Recommended Changes to Publications and Blank Forms) located in the back of this
manual, directly to: Commander, U.S. Army Aviation and Missile Command, ATTN: AMSAM-MMC-MA-NP, Redstone Arsenal,
AL 35898-5000. A reply will be furnished to you. You may also provide DA Form 2028 information to AMCOM via e-mail, fax, or
the World Wide Web. Our fax number is: DSN 788-6546 or Commercial 256-842-6546. Our e-mail address is
2028@redstone.army.mil. Instructions for sending an electronic 2028 may be found at the back of this manual immediately
preceding the hard copy 2028. For the World Wide Web use: https://amcom2028.redstone.army.mil.
Distribution Statement: Approved for public release; distribution is unlimited.
TABLE OF CONTENTS
Page
HOW TO USE THIS MANUAL
viii
CHAPTER 1 Section I.
Section II.
Section III. Tasks and Responsibilities . . . . . . . . . . . . . . . . .
CHAPTER 2 -
Section I.
Section II. General Fault Assessment Table . . . . . . . . . . . . . . .
CHAPTER 3 - GENERAL REPAIRS . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL INFORMATION
Introduction . . . . . . . . . . . . . . . . . . . . . . . .
Standards and Practices. . . . . . . . . . . . . . . . . . .
ASSESSING BATTLEFIELD DAMAGE
Introduction. . . . . . . . . . . . . . . . . . . . . . . .
1-1
1-3
1-5
2-1
2-3
3-1
CHAPTER 4 - AIRFRAME
Section I.
Introduction. . . . . . . . . . . . . . . . . . . . . . . .
Section II. Expedient Structural Repairs . . . . . . . . . . . . . . . .
4-1
4-49
CHAPTER 5 - ALIGHTING GEAR
Section I.
Introduction. . . . . . . . . . . . . . . . . . . . . . . .
Section II. Skid Tube. . . . . . . . . . . . . . . . . . . . . . . . . .
Section III. Skid Damage. . . . . . . . . . . . . . . . . . . . . . . . .
5-1
5-1
5-4
CHAPTER 6 - POWER PLANT INSTALLATION
Section I.
Section II.
Introduction. . . . . . . . . . . . . . . . . . . . . . . .
Component Expedient Fixes. . . . . . . . . . . . . . . . . .
Change 1 i
6-1
6-1
TM 55-1520-228-BD
CHAPTER 7 - ROTORS
TABLE OF CONTENTS (Cont)
Page
Section I. Introduction. . . . . . . . . . . . . . . . . . .
Section II. Repairs . . . . . . . . . . . . . . . . .
CHAPTER 8 - DRIVE TRAIN SYSTEM
Section I. Introduction. . . . . . . . . . . . . . . . . . . . .
Section II. Repair. . . . . . . . . . . . . . . . . . . . . . . .
CHAPTER 9 - HYDRAULIC
Section I. Introduction. . . . . . . . . . . . . . . . . . . . .
Section II. Lines and Hoses. . . . . . . . . . . . . . . . . . .
Section III. Seals, Packings, and Gaskets
CHAPTER 10 - INSTRUMENTS
Section I. Introduction. . . . . . . . . . . . . . . . . . . . .
Section II. Instrument Replacement
CHAPTER 11 - ELECTRICAL AND AVIONICS SYSTEM
Section I. Introduction. . . . . . . . . . . . . . . . . . . . .
Section II. Electrical and Avionics Wiring Damage. . . . . . . .
CHAPTER 12 - FUEL SYSTEMS
. . . . . . . . . . . . . .
. . . . . . . . . . . . .
7-1
7-1
8-1
8-1
9-1
9-1
9-14
10-1
10-6
11-1
11-6
Section I. Introduction. . . . . . . . . . . . . . . . . . . . .
Section II. Lines and Hoses. . . . . . . . . . . . . . . . . . .
Section III. Fuel Cell Damage.
CHAPTER 13 - FLIGHT CONTROLS SYSTEM
Section I. Introduction. . . . . . . . . . . . . . . . . . . . .
Section II. Flight Control Tubes. . . . . . . . . . . . . . . . .
CHAPTER 14 - UTILITY SYSTEMS
Section I. Introduction. . . . . . . . . . . . . . . . . . . .
Section II. De-Ice Valve or Control. . . . . . . . . . . . . . .
CHAPTER 15 - ENVIRONMENTAL CONTROL SYSTEM
Section I. Introduction, . . . . . . . . . . . . . . . . . . . .
Section II. Rigid Plastic Ventilation Duct . . . . . . . . . . .
Section III. Bleed Air Line Damage. . . . . . . . . . . . . . .
ii
. . . . . . . . . . . . . . .
12-1
12-1
12-4
13-1
13-1
14-1
14-1
15-1
15-1
15-9
TABLE OF CONTENTS (Cont)
TM 55-1520-228-BD
Page
CHAPTER 16 CHAPTER 17 CHAPTER 18 -
HOIST AND WINCHES. . . . . . . . . . . . . . . . . . . . . .
AUXILIARY POWER PLANT . . . . . . . . . . . . . . . . . . . .
MISSION EQUIPMENT . . . . . . . . . . . . . . . . . . . . . .
Section I.
Section II.
CHAPTER 19 APPENDIX A -
APPENDIX B APPENDIX C APPENDIX D APPENDIX E APPENDIX F -
EMERGENCY EQUIPMENT. . . . . . . . . . . . . . . . . . . .
REFERENCES . . . . . . . .
SPECIAL OR FABRICATED TOOLS . . . . . . . . . . . . . .
EXPENDABLE/DURABLE SUPPLIES AND MATERIALS . . . . . . . . . . C-1
SUBSTITUTE MATERIALS/PARTS. . . . . . . . . . . . . . . . . . D-1
BDAR TRAINING PROCEDURES. . . . . . . . . . . . . . . . .
AVIONICS CONFIGURATION. . . . . . . . . . . . . . . . . . . .
GLOSSARY . .
INDEX . . .
Figure
16-1
17-1
Introduction. . . . . . . . . . . . . . . . . . . . . . . .
Gun and Mount Assembly . . . . . . . . . . . . . . . . . . .
.
.
. . . . . . . . . . . . . . . . . . A-1
.
. . . . . . . . B-1
18-1
18-1
19-1
.
. E-1
F-1
✎ . . . . ✎ .. . .... ... . . . . . ...
. . . . . . . . .... . ... ... ..
GLOS-1
INDEX-1
LIST OF ILLUSTRATIONS
Title
Page
1-1
1-2
1-3
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
4-11
4-12
4-13
4-14
4-15
4-16
4-17
4-18
4-19
4-20
4-21
4-22
DA Form 2408-13. . . . . . . . . . . . . . . . . . . . . . .
DA Form 2408-18. . . . . . . . . . . . . . . . . . . . . . .
Damage Assessment Markings (Sheet 1 of 3). . . . . . . . .
Aircraft Sections. . . . . . . . . . . . . . . . . . . . . .
DA Form 2404. . . . . . . . . . . . . . . . . . . . . . . .
Evaluating Damage to Angles, Channels, and Z-Angles. . . . .
Damaged Cross Section. . . . . . . . . . . . . . . . . . . .
Measuring Skin Panel Damage. . . . . . . . . . . . . . . . .
Measuring Damage in Webs and Panels. . . . . . . . . . . . .
Measuring Damage in Honeycomb Sandwich Panels. . . . . . . .
OH-58 Helicopter. . . . . . . . . . . . . . . . . . . . . .
Airframe Reference Lines. . . . . . . . . . . . . . . . . .
Cockpit. . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuselage Pylon Support Structure (Sheet 1 of 5). . . . . . .
Upper and Lower Shell Structure. . . . . . . . . . . . . . .
Aft Fuselage Structure.. . . . . . . . . . . . . . . . . .
Tail Boom . . . . . . . . . . . . . . . . . . . . . . . . .
Cowling and Firewalls . . . . . . . . . . . . . . . . . . . .
Typical Former Repair (Sheet 1 of 2) . . . . . . . . . . . .
Cutout in Damage Skin. . . . . . . . . . . . . . . . . . . .
Patch Plate. . . . . . . . . . . . . . . . . . . . . . . . .
Typical Patch Plate Repair . . . . . . . . . . . . . . . . .
Expedient Cap/Longeron Repair. . . . . . . . . . . . . . . .
Repair of Damage Bulkhead Flange . . . . . . . . . . . . . .
Typical Combination Repair (Sheet 1 of 2). . . . . . . . . .
1-7
1-8
1-9
4-3
4-6
4-8
4-9
4-10
4-11
4-13
4-17
4-18
4-19
4-20
4-25
4-26
4-27
4-28
4-52
4-54
4-55
4-56
4-58
4-60
4-61
iii
TM 55-1520-228-BO
LIST OF ILLUSTRATIONS (Cont)
Figure
4-23
4-24
4-25
4-26
4-27
4-28
4-29
4-30
5-1
5-2
5-3
5-4
5-5
6-1
6-2
6-3
6-4
6-5
6-6
6-7
6-8
7-1
7-2
7-3
7-4
7-5
8-1
8-2
8-3
9-1
9-2
9-3
9-4
9-5
9-6
9-7
9-8
,9-9
9-10
9-11
9-12
Title
Damaged Honeycomb Core Panel, Small Damage to One Skin
and Core... . . . . . . . . . . . . . . . . . . . . . . .
Damaged Honeycomb Core Panel, 2-8 Inch Damage - One Skin
and Core. . . . . . . . . . . . . . . . . . . . . . . . .
Repaired Honeycomb Core Panel, 2-8 Inch Damage - One Skin
and Core. . . . . . . . . . . . . . . . . . . . . . . . . .
Damaged Repair,
Patch Plates, One Side Accessible Repair . . . . . . . . . .
Repair of Honeycomb Core Panel,
Skins and Core. . . . . . . . . . . . . . . . . . . . . . .
Fracture Lacing with Safety Wire . . . . . . . . . . . . . .
Tail Boom Skin Damage. . . . . . . . . . . . . . . . . . . .
Landing Gear and Support Installation. . . . . . . . . . . .
Skid Tube Damage Zones. . . . . . . . . . . . . . . . . . .
Skid Repair. . . . . . . . . . . . . . . . . . . . . . . . .
Clamp Repair. . . . . . . . . . . . . . . . . . . . . . . .
Fabricated Clamp. . . . . . . . . . . . . . . . . . . . . .
T63 Series Engine. . . . . . . . . . . . . . . . . . . . . .
Blocking Plate Installation. . . . . . . . . . . . . . . . .
Double-Check Valve System, Possible Alternatives . . . . . .
Wood Plug. . . . . . . . . . . . . . . . . . . . . . . . . .
Sealant for Small Holes... . . . . . . . . . . . . . . . .
Repair Using Screw, Washer and Gasket. . . . . . . . . . . .
Hose Assembly, Sealant, Nut, and Bolt. . . . . . . . . . . .
Sheet Metal with Sealant and/or Cherry Rivets. . . . . . . .
Main Rotor System. . . . . . . . . . . . . . . . . . . . . .
Tail Rotor System. . . . . . . . . . . . . . . . . . . . . .
Rotor Blades, Damage Sensitive Areas . . . . . . . . . . . .
Rotor Blade Repair,
Repair Areas
Drive Train System (Sheet 1 of 4). . . . . . . . . . . . .
External Components - Transmission Oil System. . . . . . . .
Flex Duct Repair (Sheet 1 of 2) . . . . . . . . . . . . . . .
Hydraulic System. . . . . . . . . . . . . . . . . . . . . .
Hydraulic System Schematic . . . . . . . . . . . . . . . . .
Two-Part Fitting. . . . . . . . . . . . . . . . . . . . . .
Four-Part Fitting. . . . . . . . . . . . . . . . . . . . . .
Using Tube Cutter. . . . . . . . . . . . . . . . . . . . . .
Properly Burred Tubing . . . . . . . . . . . . . . . . . . .
Damaged Tube Section-Straight Tube . . . . . . . . . . . . .
Splice Repair Assembly . . . . . . . . . . . . . . . . . . .
Repair Fitting and Tube Installation . . . . . . . . . . . .
Damaged Tube Section-Complex Bends . . . . . . . . . . . . .
Splice Adapter Assembly Installation . . . . . . . . . . . .
Installation of Socket and Sleeve. . . . . . . . . . . . . .
Accessible One Side Only . . . . . . . . . .
Damage Over 8 Inches - Both
Application of Tape. . . . . . . . . . .
- Main Rotor B1ades . . . . . . . . . . . . . .
Page
4-64
4-64
4-64
4-66
4-66
4-67
4-69
4-70
5-2
5-2
5-5
5-5
5-6
6-2
6-5
6-7
6-8
6-9
6-9
6-10
6-12
7-2
7-3
7-5
7-7
7-8
8-2
8-8
8-9
9-2
9-3
9-4
9-5
9-5
9-7
9-7
9-8
9-8
9-10
9-10
9-12
iv
LIST OF ILLUSTRATIONS (Cont)
TM 55-1520-228-BD
Figure
9-13
9-14
11-1
11-2
11-3
11-4
11-5
11-6
11-7
11-8
11-9
11-10
11-11
11-12
11-13
11-14
11-15
11-16
11-17
11-18
11-19
11-20
11-21
11-22
11-23
11-24
11-25
11-26
11-27
11-28
11-29
11-30
11-31
11-32
11-33
11-34
11-35
11-36
11-37
11-38
11-39
11-40
11-41
11-42
11-43
11-44
11-45
Title
Assembly of MS Fitting . . . . . . . . . . . . . . . . . . .
Union Connection. . . . . . . . . . . . . . . . . . . . . .
Circuit Identification . . . . . . . . . . . . . . . . . . .
Crimp Splice. . . . . . . . . . . . . . . . . . . . . . . .
Splicing with Terminal Lug Barrel. . . . . . . . . . . . . .
Twist Wire Splice . . . . . . . . . . . . . . . . . . . . .
Replacement Section; Twist Wire Splice . . . . . . . . . . .
Metal Casing Splice Splice. . . . . . . . . . . . . . . . .
Bolted Terminal Lug Repair of Large Wires. . . . . . . . . .
Replacement Section; Terminal Lug Repair . . . . . . . . . .
Ram Wire Repair . . . . . . . . . . . . . . . . . . . . . .
Heat-Shrinkable Tape . . . . . . . . . . . . . . . . . . . .
Insulation Repair with Sleeving. . . . . . . . . . . . . . .
Shielded Cable Repair Preparation. . . . . . . . . . . . . .
Shielded Cable Splice Preparation. . . . . . . . . . . . . .
Shielded Cable Spliced . . . . . . . . . . . . . . . . . . .
Shielded Cable Repair... . . . . . . . . . . . . . . . . .
Pigtail Method Repair . . . . . . . . . . . . . . . . . . .
Substitute Shielded Braid Repair . . . . . . . . . . . . . .
Shield Terminator Repair Preparation . . . . . . . . . . . .
Shield Terminator Repair.. . . . . . . . . . . . . . . . .
Nickel-Plated Shield Terminator Preparation. . . . . . . . .
Nickel-Plated Shield Terminator Repair . . . . . . . . . . .
Terminal Lug Repair. . . . . . . . . . . . . . . . . . . . .
Self-Clinching Cable Strap . . . . . . . . . . . . . . . . .
Self-Clinching Cable Strap and Tool. . . . . . . . . . . . .
Tie Tape Repair Procedure. . . . . . . . . . . . . . . . . .
Coax Splice Preparation.. . . . . . . . . . . . . . . . . .
Coax Splice Inner Sleeve. . . . . . . . . . . . . . . . . .
Coax Splice Shield Sleeve. . . . . . . . . . . . . . . . . .
Coax Splice with Tubing Sleeve . . . . . . . . . . . . . . .
Coax Splice with Cable Braid over Barrier Sleeves. . . . . .
Coax Repair with Cable Braid over Barrier Sleeve . . . . . .
Component Bypass. . . . . . . . . . . . . . . . . . . . . .
Connector Pin and Socket.. . . . . . . . . . . . . . . . .
Damaged Connector and Pigtail. . . . . . . . . . . . . . . .
Circuit Breakers, . . . . . . . . . . . . . . . . . . . . .
Typical Circuit Breaker Connection . . . . . . . . . . . . .
Construction of Fuse Link. . . . . . . . . . . . . . . . . .
Splicing Bus Bars. . . . . . . . . . . . . . . . . . . . . .
Lengthening Bus Bars... . . . . . . . . . . . . . . . . .
Battery, Storage BB-476/A, Cell Layout . . . . . . . . . . .
Block Diagram Power Relay, Check and Test. . . . . . . . . .
Location of Power Relays. . . . . . . . . . . . . . . . . .
Block Diagram,
Jumper Wire Fabrication.. . . . . . . . . . . . . . . . . .
Frequency vs. Wave length. . . . . . . . . . . . . . . . .
Typical Power Relays. . . . . . . . . . . . .
Page
9-12
9-13
11-2
11-8
11-10
11-11
11-12
11-12
11-14
11-14
11-14
11-16
11-16
11-17
11-18
11-19
11-20
11-22
11-23
11-24
ll-25
11-25
11-25
11-26
11-28
11-28
11-29
11-29
11-31
11-31
11-31
11-32
11-32
11-33
11-33
11-34
11-36
11-36
11-37
11-39
11-39
11-40
11-41
11-43
11-44
11-44
11-46
v
TM 55-1520-228-BD
LIST OF ILLUSTRATIONS (Cont)
Figure
11-46
11-47
12-1
12-2
12-3
12-4
12-5
13-1
13-2
13-3
13-4
13-5
13-6
13-7
13-8
13-9
13-10
13-11
14-1
15-1
15-2
15-3
15-4
15-5
15-6
15-7
F-1
F-2
F-3
F-4
F-5
F-6
F-7
F-8
F-9
F-10
Title
Preparation of Coax . . . . . . . . . . . . . . . . . . . .
Installation of Field Expedient Antenna. . . . . . . . . . .
0H-58 Fuel System. . . . . . . . . . . . . . . . . . . . . .
Emergency Mechanical Clamp Repair . . . . . . . . . . . . .
Mixing Instruction for Sealant Cartridges. . . . . . . . . .
Rubber Repair Plug Assembly. . . . . . . . . . . . . . . . .
Plug Modification for Three Plain Repair . . . . . . . , . .
OH-58 Flight Controls Schematic. . . . . . . . . . . . . . .
Collective Flight Control. . . . . . . . . . . . . . . . . .
Cyclic Flight Control . . . . . . . . . . . . . . . . . . . .
Flight Control Actuators. . . . . . . . . . . . . . . . . .
Anti-Torque Controls (Sheet 1 of 2). . . . . . . . . . . . .
Control Tube Dimensions. . . . . . . . . . . . . . . . . . .
Suggested Repair for Control Rods or Tubes . . . . . . . . .
Control Rod with Bearing and Clevis Assemblies . . . . . . .
Flattened End of Fabricated Flight Control . . . . . . . . .
Corner Rounding on Fabricated Flight Control . . . . . . . .
Bearing Assembly Connection of Fabricated Flight Control . .
Engine De-Ice System. . . . . . . . . . . . . . . . . . . .
Bleed Air Heating and Ventilating System A & C . . . . . . .
Heating and Ventilating System (Bleed Air) A Model . . . . .
Heating and Ventilating System (Bleed Air) C Model . . . . .
Combustion Heater. . . . . . . . . . . . . . . . . . . . . .
Shroud Heater System Schematic . . . . . . . . . . . . . . .
Bleed Air Line Installation. . . . . . . . . . . . . . . . .
Bleed Line Patch Repair. . . . . . . . . . . . . . . . . . .
Intercom System (Sheet 1 of 2).. . . . . . . . . . . . . .
UHF/AM Communications System (Sheet 1 of 2). . . . . . . . .
VHF/AM Communications System and Connecting Cables . . . . .
VHF/FM Communication System. . . . . . . . . . . . . . . . .
Gyromagnetic Compass Set AN/ASN-43 and Connecting Cable
(Sheet 1 of 2) . . . . . . . . . . . . . . . . . . . . . . .
Direction Finder Set AN/ARN-89 (Sheet 1 of 2). . . . . . . .
Radio Receiving Set AN/ARN-123(V)1 . . . . . . . . . . . . .
Radar Altimeter System AN/APN-209. . . . . . . . . . . . . .
Transponder (IFF) System AN/APX-72, AN/APX-100 . . . . . . .
Radar Warning System AN/APR-39 . . . . . . . . . . . . . . .
Page
11-47
11-49
12-2
12-5
12-7
12-9
12-9
13-2
13-5
13-6
13-7
13-8
13-10
13-10
13-12
13-13
13-13
13-13
14-2
15-2
15-3
15-4
15-5
15-6
15-10
15-11
F-2
F-4
F-6
F-8
F-10
F-12
F-14
F-16
F-18
F-21
Table No.
2-1
2-2
4-1
4-2
4-3
4-4
4-5
vi
LIST OF TABLES
Title
General Decision Logic . . . . . . . . . . . . . . . . . . .
General Assessment Table . . . . . . . . . . . . . . . . . .
Aircraft Structure Damage Assessment Procedures. . . . . . .
Damage Limits Forward Fuselage - Condition I . . . . . . . .
Damage Limits Aft Fuselage - Condition I . . . . . . . . . .
Damage Limits Tail Boom and Landing Gear - Condition I . . .
Damage Limits Forward Fuselage - Condition II. . . . . . . .
Page
2-2
2-3
4-2
4-31
4-36
4-39
4-39
LIST OF TABLES (Cont)
TM 55-1520-228-BD
Table No.
4-6
4-7
4-8
5-1
6-1
7-1
8-1
9-1
9-2
11-1
11-2
11-3
11-4
11-5
11-6
11-7
12-1
13-1
13-2
13-3
15-1
D-1
D-2
D-3
D-4
D-5
D-6
D-7
F-1
F-2
F-3
F-4
F-5
F-6
F-7
F-8
F-9
F-10
F-11
Title
Damage Limits Aft Fuselage - Condition II. . . . . . . . . .
Damage Limits Tail Boom and Landing Gear - Condition II. . .
Metal Substitution Chart. . . . . . . . . . . . . . . . . .
Assessment Procedure Logic . . . . . . . . . . . . . . . . .
Engine BDAR Assessment Logic . . . . . . . . . . . . . . . .
Assessment Procedures. . . . . . . . . . . . . . . . . . . .
Drive Train System BDAR Assessment Procedures. . . . . . . .
Assessment Logic. . . . . . . . . . . . . . . . . . . . . .
Seals Reference and Temperature Guides Chart . . . . . . . .
Electrical and Avionics Assessment Logic . . . . . . . . . .
Function and Designation Letters . . . . . . . . . . . . . .
Unshielded Crimp Splice Application. . . . . . . . . . . . .
Wire Repair Segments. . . . . . . . . . . . . . . . . . . .
Shielded Cable Repair . . . . . . . . . . . . . . . . . . .
Terminal Lugs. . . . . . . . . . . . . . . . . . . . . . . .
Fuse Link Strands. . . . . . . . . . . . . . . . . . . . . .
Fuel System Assessment Procedures. . . . . . . . . . . . . .
Flight Control System Assessment Procedures. . . . . . . . .
Nominal Tube Splice Sizes. . . . . . . . . . . . . . . . . .
Bolt/Drill Sizes for Control Tube Repairs. . . . . . . . . .
Assessment Procedures. . . . . . . . . . . . . . . . . . . .
Essential Spare Parts. . . . . . . . . . . . . . . . . . . .
Spare and Repair Parts . . . . . . . . . . . . . . . . . . .
Weapons. . . . . . . . . . . . . . . . . . . . . . . . . . .
Substitute Fuels for JP-4 Fuel . . . . . . . . . . . . . . .
Fuels for the OH-58 Helicopter . . . . . . . . . . . . . . .
Substitute Commercial Fuels . . . . . . . . . . . . . . . .
Alternate and Expedient Fuel Blends. . . . . . . . . . . . .
Wire Table, Intercom System. . . . . . . . . . . . . . . . .
Wiring Table, UHF/AM Communication System. . . . . . . . . .
Wiring Table,
Wiring Table, VHF/FM Communication System. . . . . . . . . .
Wiring Table, Gyromagnetic Compass Set . . . . . . . . . . .
Wiring Table, ADF AN/APN-89
Radio Receiving Set AN/ARN-123(V)1, OH-58C . . . . . . . . . .
Wiring Table, Radar Altimeter AN/APN-209, OH-58C . . . . . .
Wiring Table, IFF, APX-72, OH-58A . . . . . . . . . . . . .
Wiring Table,
Wiring Table, AN/APR-39 . . . . . . . . . . . . . . . . . . .
VHF/AM Communication System. . . . . . . . . .
IFF, APX-1OO, OH-58C . . . . . . . . . . . . .
Page
4-44
4-47
4-50
5-3
6-3
7-4
8-6
9-4
9-18
11-2
11-3
11-7
11-16
11-18
11-27
11-37
12-3
13-3
13-11
13-11
15-7
D-2
D-3
D-5
D-7
D-8
D-9
D-10
F-3
F-5
F-7
F-9
F-11
F-13
F-15
F-17
F-19
F-20
F-22
vii
TM 55-1520-228-BD
HOW TO USE THIS MANUAL
This manual is developed to assist the soldier in a battlefield environment to make
assessment and repair of damage to the OH-58 helicopter which cannot, due to asset
availability or environmental factors,
Within this technical manual,
requirement.
The word should is used to indicate a nonmandatory but preferred
the word shall is used to indicate a mandatory
method of accomplishment. The word may
be repaired in the normal prescribed manner.
is used to indicate an acceptable method of
accomplishment.
Organization of the Manual.
1.
This manual contains a general information chapter
(chapter 1), a general assessment chapter (chapter 2), and specific repair chapters
(chapters 4 thru 19).
Chapter 3 is not used.
It also contains five appendices.
References (Appendix A), special or fabricated tools (Appendix B),
expendable/durable supplies and materials list (Appendix C), substitute materials
and parts (Appendix D), and BDAR fixes authorized for training (Appendix E).
Chapter 2 is used to assess the helicopter in general and references specific
2.
chapters for detailed repair procedures of the major functional groups.
The major
functional groups correspond with the functional groups of the -23 series manuals
that are employed in routine repairs to the helicopter.
Chapter 3 is not used in this manual.
3.
It would normally contain repairs for
equipment which does not fall under one of the standard helicopter functional groups.
4.
Each functional group chapter is organized as follows:
a. Section I
(1) Scope.
(2) Assessment procedures.
- Introduction.
Purpose of the chapter.
General assessment information for the repairs
covered therein.
(3) Repair procedure index.
Section II
b.
- Repair Item.
covered in that functional group.
A subsection is included for each repair item
It contains the following:
(1) General.
About the nature and cause of damage and repair.
(2) Item and trouble statement with:
(a) Limits given.
(b) Personnel and time required to effect repairs.
(c) Materials and tools needed.
(d) Procedural steps to accomplish the repair.
(3) If more than one method of repair can be used, the various options will
be included next.
NOTE
The first option is the preferred choice, the second option
is the next preferred, etc.
Selection of the option should
be the most preferred method possible under the circumstances
and with the available materials and manpower.
viii
HOW TO USE THIS MANUAL (Cont)
5.
Finding Repairs in this Manual.
TM 55-1520-228-BD
a. When the damage is obvious and known,
which the damaged item is a part.
Turn to the repair procedure index, section I,
find the functional group chapter of
subparagraph c of each chapter to locate the item being repaired. Then turn to the
repair section and review each option to ascertain the appropriate fix.
entire section for the option,
then effect the repairs following the procedures
Read the
given.
b.
When the damage is hidden and/or unknown,
follow the overall assessment proce-
dures provided in chapter 2, and follow the procedures and directions provided.
6.
Preparation.
a. Each mechanic/technician shall have read chapters 1 and 2 and become familiar
with the repairs and layout of the manual prior to attempting to accomplish BDAR
repairs.
b.
All warnings,
cautions, and safety precautions shall be followed, inasmuch as
possible, at all times during BDAR procedures so as not to further damage and/or
jeopardize either personnel or the equipment during or subsequent to the BDAR
action.
Ensure all documentation is completed as directed in this manual and by
local command.
7.
Expendable/Durable Supplies and Materials.
a. Each fix or repair option contains a short listing of materials and tools considered basic to the repair. It is important to note that the expendable materials
listed usually cover a wide range for any one item.
Example:
MATERIALS/TOOLS REQUIRED:
●
Drill with Bit
●
Sheet Metal (items 131-142, Appx C)
●
Rivets (items 98-115, Appx C)
In this example, sheet metal covers the range of items 131 thru 142 in Appendix C.
This means that, depending on the circumstances and location of the fix, any one of
these metals could be used.
Likewise any one of the rivets, items 98 thru 115, may
be used to attach the patch plate depending on the application.
b.
One of the key points concerning successful BDAR repairs is flexibility. The
users of this manual should strive to use the items on hand, provided a safe repair
is made.
The stringent requirements of normal maintenance may be lifted.
ix/(x-Blank)
TM 55-1520-228-BD
CHAPTER 1
GENERAL INFORMATION
BDAR FIXES SHALL BE USED ONLY IN COMBAT OR FOR TRAINING
AT THE DISCRETION OF THE COMMANDER.
(AUTHORIZED TRAINING FIXES ARE LISTED IN APPENDIX E.)
IN EITHER CASE, DAMAGES SHALL BE REPAIRED BY STANDARD
PROCEDURES AS SOON AS PRACTICABLE.
Section I. INTRODUCTION
1-1.
PURPOSE.
Damage Assessment and Repair (BDAR) is
to quickly return the disabled heli-
copter to the operational commander by
expediently fixing, bypassing, or jury-
rigging components to restore the mini-
mum essential systems required for the
support of the specific combat mission
for self-recovery. These repairs will
be temporary and may not restore full
performance capability. Standard repair
will be completed as soon as practical.
1-2.
cribes BDAR procedures applicable to
OH-58 helicopter series, and these
procedures are to be used by crew,
operators, aviation unit maintenance
(AVUM) teams, and aviation intermediate
maintenance (AVIM) support teams.
OH-58 helicopter are included in other
technical manuals which are referenced
in Appendix A of this TM. Details of
these procedures are not duplicated in
whole in this TM.
more than one page in length, the
repairs may only be referenced in
appropriate chapter.
damage and failure modes cannot be predicted, nor are all effective field
expedient repairs known.
vides guidelines for assessing and
repairing battlefield failures of OH-58
helicopters and is not intended to
SCOPE.
a.
This technical manual (TM) des-
b.
Standard repair techniques for the
c.
All possible types of combat
The purpose of Battle
If the repairs are
This TM pro-
be a complete catalog of all possible
emergency repairs. The repairs described
here will serve as guidelines and will
stimulate the experienced mechanic/
operator to devise repairs as needed to
rapidly return equipment to operation in
a combat situation.
d.
of equipment by its spare, even under
battlefield conditions, is not a BDAR
fix and may not be covered is in this
TM.
formed in preference to a BDAR fix when
time and spares are available.
1-3. APPLICATION.
a. The procedures in this manual are
designed for battlefield environments
and should be used in situations where
standard maintenance procedures are
impractical. These procedures are not
meant to replace standard maintenance
practices, but rather to supplement them
strictly in a battlefield environment.
Standard maintenance procedures will
provide the most effective means of
returning damaged equipment to ready
status provided that adequate time,
replacement parts, necessary tools, and
trained/qualified repair persons are
available. BDAR procedures are only
authorized for use in an emergency
situation in a battlefield environment,
and only at the direction of the commander. They are not to be continued
after the equipment is out of the battle
environment.
The direct replacement of a piece
A standard procedure should be per-
1-1
TM 55-1520-228-BD
GENERAL INFORMATION
BDAR techniques are not limited to
b.
simple restoration of minimum functional
combat capability.
capability can be restored expediently
with a limited expenditure of time and
assets, it will be accomplished.
c. Some of the special techniques in
this manual,
shortened life or in further damage to
major components of the helicopter.
commander must decide whether the risk
of having one less helicopter available
for combat outweighs the risk of
applying the potentially destructive
expedient repair technique.
nique gives appropriate warnings,
cautions, and lists systems limitations
caused by this action.
1-4.
such as combat damage, random failures,
operator errors, accidents, and wear-out
failures which occur on the battlefield
and which prevent the helicopter from
accomplishing its mission.
action that returns a damaged part or
assembly to a full or an acceptably
degraded operating condition, including:
installation.
from other equipment that can be
modified to fit or interchange with
components on the damaged equipment.
a noncritical function elsewhere on
the same equipment for the purpose of
restoring a critical function.
DEFINITIONS.
a. Battlefield Damage.
b. Repair
(1) Short cuts in parts removal or
(2) Installation of components
(3) Repair using parts that serve
if applied, may result in
or Fix. Any expedient
If full functional
The
Each tech-
Any incident
or readily available materials.
c. Damage Assessment. A procedure to
rapidly determine what is damaged,
whether it is repairable, what assets
are required to make the repair, who can
do the repair (e.g., crew, maintenance
team or maintenance support team), and
where the repair should be made.
assessment procedure includes the
following steps:
deferred, or if it must be done.
components.
must be fixed.
ponents, materials, and tools are
available.
skill required.
hours) required to make the repair.
fixes.
performed.
tion is necessary and to what location.
(6) Fabrication of parts from kits
(7) Jury-rigging.
(8) Use of substitute materials.
The
(1) Determine if the repair can be
(2) Isolate the damaged areas and
(3) Determine which components
(4) Prescribe fixes.
(5) Determine if parts or com-
(6) Estimate the manpower and
(7) Estimate the total time (clock
(8) Establish the priority of the
(9) Decide where the fix shall be
(10) Decide if recovery or evacua-
(4) Bypassing of noncritical com-
ponents in order to restore basic func-
tional capability.
(5) Expeditious cannibalization
procedures.
1-2
d.
helicopter can perform all its combat
missions. To be FMC, the helicopter must
be complete and fully operable with no
faults listed in the aircraft inspection
and maintenance record as prescribed in
DA PAM 738-751.
Fully Mission Capable (FMC). The
TM 55-1520-228-BD
GENERAL INFORMATION
e. Combat Capable.
the minimum functional combat capability
requirements.
(See paragraph 1-8. )
Equipment meets
j.
battle damaged helicopter to retrieve
itself (fly out) from a battlefield
environment.
f.
Combat Emergency Capable. The
equipment meets the needs for specific
tactical missions; however, all systems
are not functional.
Also, additional
damage due to the nature of an expedient
repair may occur to the equipment if it
is used.
The commander must decide if
these limitations are acceptable for
that specific emergency situation.
g.
Cannibalization or Controlled
Exchange.
Throughout this manual, can-
nibalization and controlled exchange are
flying with degraded flight status and
with restrictions and limitations placed
on performance characteristics such as
limitations placed on weight, airspeed,
engine torque, and other characteristics.
In BDAR repairs,
mended should be followed.
flight procedure in TM 55-1520-228-10
should further be consulted.
k.
point operated by AVIM unit for the
collection of equipment for repair.
used interchangeably meaning the removal
of an item of materiel from one piece of
equipment for immediate use in another.
Generally the rules for cannibaliza-
tion/controlled exchange provided in
TM 55-1500-328-25,
as modified by local
1.
team of AVIM mechanics and technical
specialists who are trained in assessing
battlefield damage and field repair
procedures.
authority, will prevail.
m.
h.
Evacuation,
port function which involves the move-
A combat service sup-
ment of recovered helicopters from a
main supply route,
maintenance collection point, or maintenance activity to
higher categories of maintenance. The
materiel may be returned to the user, to
the supply system for reissue, or to
property disposal activities.
crew chief or AVUM mechanics/technicians
who are trained in assessing battlefield
damage and field repair procedures.
1-5. QUALITY DEFICIENCY REPORT/EQUIP-
MENT IMPROVEMENT RECOMMENDATION
(QDR/EIR). If your helicopter and its
equipment need improvement, let us
know:
are the only one who can tell us what
i.
Recovery.
bile, inoperative,
The retrieval of immo-
or abandoned OH-58
helicopter from the battlefield or
immediate vicinity, and its movement
to a maintenance collection point, the
main supply route, or a maintenance
activity for disposition, repair, or
evacuation.
you don’t like about your equipment.
Let us know why you don’t like the
design. Put it on an SF 368 (Quality
Deficiency Report). Mail it to
Commander, U.S. Army Aviation Systems
Command, ATTN:
Goodfellow Boulevard, St. Louis, MO
63120-1798. We’ll send you a reply.
Self-Recovery.
The ability of a
It usually will involve
the limitations recom-
Emergency
Maintenance Collection Point. A
Maintenance Support Team (MST).
Maintenance Team (MT).
Helicopter
A
Send us an EIR. YOU, the user,
AMSAV-QF, 4300
Section II. STANDARDS AND PRACTICES
1-6.
BDAR CHARACTERISTICS. BDAR capa-
bility requires simplicity, speed, and
effectiveness. Some BDAR procedures
include repair techniques that violate
standard peacetime maintenance practices.
In a combat emergency situation, greater
risks are sometimes necessary and
acceptable.
1-3
TM 55-1520-228-BD
GENERAL INFORMATION
1-7.
combat conditions, BDAR may be performed
on helicopters which are in flight or
which are under power while on the
ground.
may require waiving of safety precautions,
the cautions to protect personnel life
should not be overlooked.
precautions may be waived at the discre-
tion of the commander.
be required in a chemically toxic environment or under other adverse battlefield
conditions with severe limitations in
personnel, facilities, equipment, and
materials. Performance of repair tasks
may be necessary while wearing protective
gear.
described in FM 3-5.
1-8
manual covers expedient repairs for the
OH-58 helicopter and its components. It
is entirely possible that in a combat
situation, the helicopter having undergone one or more repairs may suffer
degradation of its normal operating
characteristics (e.g., reduced speed,
reduced load capability, reduced range,
etc.), and still be able to carry out
all or parts of an assigned mission.
The minimum functional combat capability
(MFCC) criteria for the OH-58 is as
follows:
Completion. Helicopter’s flight characteristics degraded to a minimum of
combat capable (CC).
main and tail rotor to accommodate lift
capability for helicopter crew and cargo.
tail the intended length of flight.
WAIVER OF PRECAUTIONS. Under
While some of these BDAR actions
Other similar
BDAR fixes may
Decontamination procedures are
OPERATING CHARACTERISTICS. This
a.
Flight Capability for Mission
(1) Sufficient power delivered to
(2) No fuel leaks which will cur-
intercom communications within aircraft
and at least two tactical receivertransmitter (R-T) units operating at
full capability.
Self-Recovery Capability (SRC).
main and tail rotor at acceptable
limits.
members. Unload unnecessary weight.
function level acceptable for flight.
required to meet mission needs.
2 hours.
to minimize flight duration.
procedures.
Chapter 9.
(4) Communications. Must have
Criteria may be waived for
recovery or if the tactical
situation demands otherwise.
b.
Flight Capability for
(1) Must have power delivered to
(2) Maximum engine torque:
(3) Lift capability for crew
(4) Flight controls at minimum
(5) Instruments/avionics as
(6) Maximum airspeed of 50 kts.
(7) Maximum flight duration of
(8) Be prepared for emergency
NOTE
80% at 0 kts
64% at 16 kts
53% at 32 kts
50% at 50 kts
Consideration will be given
See TM 55-1520-228-10,
(3) No degradation of any component/system which will end in failure
and curtailment of intended mission.
1-4
TM 55-1520-228-BD
GENERAL INFORMATION
WARNING
outside authorized standard repairs, and
may degrade the inherent safety of the
Careful consideration shall be given
to the operation of the Identify
Friend or FOE (IFF), Mode 4,
avionics system.
Failure of the
IFF or failure to properly communi-
helicopter.
not intended to supplement, replace stan-
dard maintenance practices during peace-
time, nor should they be employed indis-
criminately to facilitate training.
cate with area air defense command
prior to liftoff could result in an
attack from friendly forces due to
mistaken identity.
b.
which can be appropriately accomplished
in order to provide training, are listed
in Appendix E and are highlighted in each
1-9.
TRAINING.
repair chapters repair procedure index.
The trainable repair in the index will be
a. BDAR by its nature involves fixes,
blocked
bypasses, and/or jury-rigging, which is
Section III.
TASKS AND RESPONSIBILITIES
1-10. TAGGING/IDENTIFYING BDAR REPAIRS.
inside a red circle indicates a limiting
a. All damage will be identified on
aircraft inspection and maintenance
record, DA Form 2408-13 and DA Form
2408-18, as per DA PAM 738-751. See
defect.
specific limits as directed by higher
authority, or as directed locally until
corrective action is taken.
Figures 1-1, 1-2.
Recording of BDAR repairs and the
b.
use of status symbols, as defined in DA
PAM 738-751, will be completed as soon
as practical to indicate any limita-
tions and restrictions or required stan-
dard repairs.
inspection,
ponent replacement, maintenance opera-
tional check, or test flight is needed.
The symbol is also used to indicate that
a normal modification work order (MWO)
c. In addition to recording all
is overdue.
damage, the area damaged will be marked
on aircraft or component part using
damage assessment markings as shown in
Figure 1-3.
the condition of the equipment is
unknown. A potentially dangerous condition may exist.
d.
Status Symbols. Status symbols
corrected as soon as possible.
used in aircraft logbooks to record
defects are defined below.
indicates a defect exists that is not
(1) Red “X.”
A red “X” shows that
serious enough to ground the aircraft.
a defect exists and the aircraft is
unsafe for flight.
Therefore, BDAR actions are
Repairs described in this manual,
in.
(2) Circled red “X.” A red “X”
The aircraft may be flown under
(3) Red horizontal dash (-).
(a) This symbol indicates an
special inspection, com-
(b) This symbol also shows that
The condition will be
(4) Red diagonal (/). This symbol
1-5
TM 55-1520-228-BD
GENERAL INFORMATION
e. Maintenance of Forms. Instructions for the maintenance of forms,
records, and reports are listed in DA
PAM 738-751 and TB 55-1500-307-24. When
requires an inspection at intervals,
list the required inspection on DA Form
2408-18.
battle damage assessment and repair
(BDAR) becomes necessary, the procedures
in DA PAM 738-751 will apply. Refer to
in block 5.
Figures 1-1 and 1-2 for examples.
(1) In block 17 of DA Form
block 6.
2408-13, list the fault.
(2) In block 16 of DA Form
inspection in block 7.
2408-13, enter the status symbol.
1-11. REPORTS. All written reports
(3) In block 18 of DA Form 2408-13,
enter the corrective action taken.
required for BDAR fixes are found in DA
PAM 738-751.
longer fly, the aircraft commander
(4) The individual completing the
repair will sign the form in block 19
opposite the first line of the action
taken, and will place his last name ini-
tial over the status symbol in block 16.
should immediately initiate an out-ofaction report to his superior.
munications capability is damaged, the
aircraft commander should approach the
nearest friendly radio and make his
report if possible. The report should
f.
Temporary Repair. If the repair
include these essentials:
is temporary, take the following addi-
tional action:
a. Aircraft damage (out-of-action or
function partially impaired).
(1) In block 18 of DA Form 2408-13,
enter the corrective action and a state-
b.
ment that the repair is temporary. Then
make an entry in DA Form 2408-14, block
The entry will be a duplicate of the
b.
entry in block 17 of DA Form 2408-13 to
c. Defense status.
d.
include a statement that a temporary
repair has been made.
e. Personnel report.
(3) If the temporary repair
(a) Enter item to be inspected
(b) List the applicable TM in
(c) State the frequency of the
If the helicopter can no
If com-
Location of aircraft.
Mobility.
NOTE
Faults with status symbol of red "x", or
circle red "x" will not be entered on
DA form 2408-14.
(2) If the temporary repair limits
f.
action.
g.
time.
the capability of the aircraft, the
following entry will be made on DA Form
2408-13:
(a) Place a circled red “X” in
block 16.
(b) State the limitation in
block 17.
1-6 Change 1
Current and anticipated hostile
Anticipated BDAR fixes and repair
TM 55-1520-228-BD
GENERAL INFORMATION
1. DATE 2 MODEL
7
1
2
3
11
SERV-
ICE
NO.
TOTAL
16
STATUS
AIRCRAFT
1
2
3
4
5
6
7
17
STATUS TODAY
ELEC-
TRONIC
4
5
6 TIME
FUEL (Gals or Lbs)
GRADE
ADDED
ARMA-
MENT
TOTAL
IN
TANKS
OTHER
12
ADDED
GRADE
FAULTS AND/OR REMARKS
N0.
ENG
3. SERIAL NO.
8
AIRCRAFT TIME
TIME TO
DATE
TIME TO-
DAY
TOTAL
OIL ( Quarts)
TOTAL
1
IN
TANKS
4 NAME OF CREW CHIEF/MECHANIC 5 STATlON
9
NEXT INSPECTION DUE
INTMED
NO.
P.E. NO.
OTHER
14
ADDED
N0. 2
ENG
TOTAL
IN
TANKS
APU
13
0XYGEN
(PSI)
18.
I
ENGINE
PREVIOUS
TODAY
TOTAL
ANTl-
ICING
FLUID
(Gals)
ACTION TAKEN
15
HOT STARTS
N0.1
NO. 2
ENGINE
BY
6 PAGE NO.
LANDINGS
b
SERVICED
19
6a NO. OF PAGES
OTHER
c
STATION
SIGNATURE
I
DA FORM 2408-13, 1 DEC 66
REPLACES EDITION OF 1 JAN 64, WHICH WILL BE USED
Figure 1-1. DA Form 2408-13
I
I
AIRCRAFT INSPECTION AND MAINTENANCE RECORD
For use of this form see DA PAM 738-751, the proponent army is DCSLOG
1
1-7
TM 55-1520-228-BD
GENERAL INFORMATION
1. NOMEN CLATURE
5.
ITEM TO BE INSPECTED
2. MODEL 3. SERlAL NUMBER 4. PAGE NO.
NO. OF PAGES
6.
REEFERENCE
7.
FREQUENCY
8.
NEXT DUE
●
DA FORM 2404.18. 1 JAN 64
1-8
Figure 1-2. DA Form 2408-18
EQUIPMENT INSPECTION LIST
For use
of this form, see TM 38-750;
the proponent agency is DCSLOG.
TM 55-1520-228-BD
GENERAL INFORMATION
MEANINGS
TO INDICATE DAMAGE HAS BEEN ASSESSED AND EVALUATED:
Draw a circle around the damage.
TO INDICATE NO BDAR REPAIR REQUIRED:
Write “OK” inside the circle.
TO INDICATE STRUCTURAL REPAIRS ARE REQUIRED:
Draw a second line about 1/4 to 1/2
way around the initial circle then
draw slashes or crosshatch between
the two circular lines.
STRINGER REPAIR:
left and right of the circle.
FRAME REPAIR: Place an X above and
below the circle.
Place an X to the
MARKINGS
TO INDICATE DAMAGE TO SYSTEMS REQUIRING REPAIRS:
Draw a series of “curly cue” lines about
1/4 to 1/2 way around the initial circle.
TO INDICATE REPAIR INSTRUCTIONS:
For internal damage - draw a dashed
circle around the repair instructions.
For external damage - write repair
instructions but do NOT enclose
with a circle.
Figure 1-3.
Damage Assessment Markings (Sheet 1 of 3)
1-9
TM 55-1520-228-BD
GENERAL INFORMATION
WRITTEN INSTRUCTIONS
See me -
print name &
rank. (Signature)
Names of parts to
be repaired, (item,
skin, stringer.
Full
Partial
See assessor or whoever has signed written instructions
for additional information.
Where compound damage occurs, the names or abbreviations
of specific items can be written adjacent to the damage
to clarify repair instructions.
A full strength repair is required.
Partial strength repair required in accordance with
MEANING
specific aircraft BDAR manual.
OK
No repairs required - damage is within acceptable limits
for battle conditions.
?
Continual assessment or reinspection is required after
each sortie.
Instruction markings for system are in two parts:
(1) Repair instruction markings and meanings are shown on this sheet and are
used to indicate repair actions required.
(2) System Identification - When known,
identify the system using markings
shown on sheet 3 of this figure.
MARKINGS MEANING
Fix
Repair the damaged system in accordance with approved
standard BDAR techniques for type of system, item,
high pressure, low pressure, etc.
Cap
Repl
OK
Tag
Terminate or block the system to prevent leakage.
Replace damaged part -
repairs not acceptable.
No repairs required.
Repair instructions are written on tags tied to indivi-
dual damaged lines/components.
1-10
Figure 1-3.
Damage Assessment Markings (Sheet 2 of 3)
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