Tail Boom Skin Damage - Bell OH-58A Technical Manual

TM 55-1520-228-BD
AIRFRAME
LIMITATIONS: None - Condition 1.
Inspect after every flight for
damage growth.
PERSONNEL/TIME REQUIRED:
1 Soldier
. 2 Hours
MATERIALS/TOOLS REQUIRED:
Skin Patch
Cherry Rivets (item 37, Appx C)
EA93NA Adhesive (item 6, Appx C)
PROCEDURAL STEPS:
Remove sections of the tail boom
1.
skin containing the damage. Stop
drill remaining cracks. Clean up
damaged skin using a minimum 0.125
inch radius.
4-70
Figure 4-30. Tail Boom Skin Damage
Prepare a patch of 2024-T3 aluminum
2.
0.050 thick and shape to contour of tail
The patch must extend a minimum of
boom.
3 inches forward and aft, and 1 inch above
and below the damaged area, Figure 4-30.
3. Sand surfaces lightly to remove all
surface finish. Clean areas with cleaner.
Bond patch to surface with EA934NA
adhesive.
4. Install a minimum of three rows of
rivets running circumferentially on each
end and a minimum of one row of rivets
top and bottom running longitudinally in
the patch. Rivet size to be the same as
skin lap joints, Figure 4-30.
5. Record BDAR action taken. When
mission is complete, as soon as
practical, repair the equipment/system
using standard maintenance procedures.