Bell OH-58A Technical Manual page 226

TM 55-1520-228-BD
FUEL SYSTEMS
12-7. FUEL CELL DAMAGE.
GENERAL INFORMATION: The fuel cells
restrict the catastrophic loss of fuel
in survivable crashes.
cified in this section, however, will
not necessarily return the cells to
their original crash resistant level.
Fuel cell damage can be categorized as
follows:
a. Nonrepairable:
(1) Damage to metal plate of fit-
tings on tank which causes leakage.
(2) Damage to tank wall which
exceeds 3 inches.
(3) Damage within 2 inches of
metal fitting.
b. One-Time or Emergency Flight
Capability Repair:
Mechanical Clamp Repair (option 1).
c. 100 Flight Hour Capability Repair:
(1) Adhesive repair (option 2).
(2) Flat panel repair, one plane
(option 3).
(3) Two plane repair (option 4).
(4) Three plane repair (option 5).
OPTION 1: Mechanical Clamp Repair.
Emergency flight repair.
LIMITATIONS:
PERSONNEL/TIME REQUIRED:
. 1 Soldier
. 30 minutes
MATERIALS/TOOLS REQUIRED:
. Mechanical Repair Sealing Clamp
(3 or 5 inch)
. Knife
12-4
Section III. FUEL CELL DAMAGE
The repairs spe-
PROCEDURAL STEPS:
1. Defuel the fuel cell by the
following procedure:
a. Remove the fuel drain cover panel.
b. Push or twist drain valve located
under aircraft where fuel pump is located.
c. Place a bucket or any type recep-
tacle under the aircraft to catch the
fuel.
2. Locate the damage (e.g., hole or
tear) on the cell.
NOTE
For holes less than 2 inches across,
use the 3 inch clamp.
greater than 2 inches across but
less than 3 inches across, use
the 5 inch clamp. Holes larger
than 3 inches are nonrepairable.
3.
Use the knife to enlarge the hole to
3/4 inch to 2 inches maximum for a 3
inch clamp and 1 inch to 3 inch maximum
for the 5 inch clamp.
4. Insert the bottom plate of the clamp
through the hole and pull up using the
cord. Position the plate so the hole is
entirely within the gasket area. Slip
the top plate over the threaded stud and
hand tighten the wing nut, Figure 12-2.
CAUTION
Excessive mechanical tightening
of the wing nut can result in
failure of the clamp. The wing
nut shall be finger tightened,
and the maximum torque on the
wing nut shall not exceed 10 to
12 inch-pounds.
5. Tighten drain valve and install
cover plate.
For holes