Bell OH-58A Technical Manual page 141

BDAR FIXES SHALL BE USED ONLY IN COMBAT OR FOR TRAINING
(AUTHORIZED TRAINING FIXES ARE LISTED IN APPENDIX E.)
IN EITHER CASE, DAMAGES SHALL BE REPAIRED BY STANDARD
8-1. GENERAL. The drive train is a
system of shafts and gearboxes through
which the engine drives the main rotor,
tail rotor, and such accessories as
rotor tachometer generator and hydraulic
pump. (See Figure 8-1 for drive train
system configuration.)
8-2. DRIVE TRAIN DAMAGE. The drive
train system does not lend itself well
to limited repairs. In most instances,
the only repair options for a faulty
component will be to replace or repair
by normal procedures. Those limited
repairs which have been developed are
listed in this section.
8-5. SENSITIVITY OF DRIVE TRAIN SYSTEM
TO BATTLEFIELD DAMAGE. The drive train
system includes a number of components
which, if damaged or deformed (bent) in
any way or fail internally, will render
the system inoperable or severely
degrade flight characteristics or
safety. The system is particularly sen-
sitive to any damage which adversely
affects any of the following:
a. Internal operation of transmission,
freewheeling assembly, or tail rotor
gearbox.
b. Operation of the transmission oil
system.
CHAPTER 8
DRIVE TRAIN SYSTEM
AT THE DISCRETION OF THE COMMANDER.
PROCEDURES AS SOON AS PRACTICABLE.
Section I. INTRODUCTION
8-3. ASSESSMENT PROCEDURES. Refer to
Table 8-1.
8-4. REPAIR PROCEDURES INDEX.
Section 11. REPAIR
Drive Train Damage. . . . . . 8-2
Drive Train Component Damage. 8-5
Transmission Oil Cooling Air
Duct Repair . . . . . . . . 8-6
Oil Pressure Transmitter Leak 8-7
Low Pressure Sensing Switch . 8-8
Oil Hoses and Lines, Leaks
or Restrictions . . . . . . 8-9
Transmission Bullet Damage. . 8-10
Tail Rotor Gearbox Bullet
Damage. . . . . . . . . . . 8-11
c. Straightness, original shape, or
integrity of either the mast, drive-
shafts, or output shaft at tail rotor
gearbox.
8-6. AIR DUCT HOSE DAMAGE.
GENERAL INFORMATION: Holes, tears, or
distortions in air duct hose (16, Figure
8-2) can result in less than the
required amount of cooling air reaching
the oil cooler (2, Figure 8-2). This
condition may cause the transmission oil
system to operate at above normal tem-
perature. Several repairs can be
applied depending on accessibility and
the nature and extent of damage
incurred. Various repairs are shown at
Figure 8-3.
TM 55-1520-228-BD
PARA .
8-1