Bell OH-58A Technical Manual page 112

TM 55-1520-228-BD
AIRFRAME
PROCEDURAL STEPS:
1. Remove protruding sections of
damaged skins and core. Clean area with
solvent.
2. Cut patch plate to fit over hole,
allowing 1 inch overlap on all sides.
Lay out and drill rivet pattern on
3.
overlapping area.
4. Apply sealant to underside of patch
plate on overlapping area.
5. Assemble patch plate to panel with
rivets.
6. Record BDAR action taken. When
mission is complete, as soon as
practical, repair the equipment/system
using standard maintenance procedures.
4-21. WINDOW SHIELD/WINDOW DAMAGE.
GENERAL INFORMATION: In general,
repairs to transparencies are at best
make-shift and usually result in serious
impairment of clear vision charac-
Damaged sections should be
teristics.
replaced as soon as possible.
Restricted vision.
LIMITATIONS:
Inspect after every flight for damage
growth.
PERSONNEL/TIME REQUIRED:
Soldier
1
1 Hour
MATERIALS/TOOLS REQUIRED:
. Safety Wire (item 25, Appx C)
Sealant (item 4, Appx C)
. Tape (item 50, Appx C)
PROCEDURAL STEPS:
1. Stop drill a hole at the end of each
crack, Figure 4-29. If tolerable, cut
out a hole to include the ends of all
cracks. This will restrict vision
Smooth ragged edges.
further.
4-68
2. Drill small holes 1/2 to 3/4 inch
spacing, 3/8 inch edge distance along
both sides of any crack and along the
sides of the hole.
3. Lace safety-wire with needle nose
pliers through holes and across cracks
and over hole, forming a web with 1/2 to
3/4 inch spacing between wires. Pull
wires tight.
4. Brush epoxy sealant over safety wire
and crack to make a water tight seal.
NOTE
Holes too large to be closed with
safety-wire and epoxy may be sealed
temporarily with Army green tape.
5. Record BDAR action taken. When
mission is complete, as soon as
practical, repair the equipment/system
using standard maintenance procedures.
4-22. TAIL BOOM SKIN DAMAGE.
GENERAL INFORMATION: The tail boom is a
basic monocoque structure with no longi-
tudinal skin stiffeners or longerons.
The tail boom is unserviceable if damage
is extensive enough to cause misalign-
ment. Damage which does not exceed 10
percent of tail boom circumference in
height and 30 percent of tail boom cir-
cumference in length may be repaired by
patching. (Circumference to measured
at aft end of damage.) A maximum of TWO
damaged areas per stress section of the
tail boom is permitted. Example, a line
drawn around the circumference of the
tail boom must not touch more than TWO
Damaged areas must be a
damaged areas.
minimum of 8 inches apart. Total damage
to tail boom is not to exceed 5 percent
of the tail boom area (approx. 160
square inches).