INSPECT LOWER DRIVE ARM
Technical Inspection Tool Kit, NSN 5180-00-323-5114
Vernier Caliper, 3 Inch
Crocus Cloth (E122)
Aircraft Powertrain Repairer
Off Helicopter Task
Procedure is the same to inspect a
forward or aft lower drive arm.
Check Teflon coating on bearing (1). Coating
shall not be torn, scored, or frayed.
Check two shoulder bushings (2) in lower drive
arm (3). Bushings shall not be loose.
Measure inside diameter of bearing (1). Diameter
shall not exceed 0.3755 inch.
Measure inside diameter of bushings (2).
Diameter shall not exceed 0.5647 inch.
Check the bearing surface of each bushing (2)
for damage. Blend out minor surface damage
with crocus cloth (E122). If damage cannot be
blended smooth, reject the drive arm.
Check all surfaces of drive arm (3) for scratches,
pits, or other damage. Damage not exceeding
0.005 inch deep shall be accepted without
rework. Damage between 0.005 inch and 0.040
inch deep shall be blend repaired. Depth of
blend repair shall not exceed 0.040 inch or 10
percent of material thickness, whichever is less.
Blend radius must be at least 1 inch.