TM 55-1520-240-23-5
6-51
INSTALL FORWARD TRANSMISSION PACKAGE
(Continued)
6-51
Transmission is heavy and can injure
personnel if it drops. Transmission
must be supported by hoist and
moved carefully to prevent injury to
personnel.
5.
Raise transmission (9) and center it over support
structure (10). Check that hoisting eye (T32) (1)
points aft. Have helpers guide transmission with
guide lines (8).
FLIGHT SAFETY PARTS
This is an installation critical flight
safety part. All aspects of its assembly
and installation must be ensured.
Ensure transmission is suspended 1
inch above structure when installing
each of the bolts (14). This will
help provide proper alignment of the
transmission and reduce possible
scoring of bolt shank.
After transmission is lowered on to
structure, ensure each bolt (14) is
torqued to 885 foot-pounds. Proper
torquing of the bolts (14) ensures
proper distribution of flight loads
through the structure.
If the torque requirements are not
met, the bolts (14) can disengage and
allow the transmission to separate
from the aircraft structure.
NOTE
While lowering transmission, turn it as
needed for clearance.
6.
Carefully lower transmission (9). Have helpers
align mounting hole (11) in each of four lugs (12)
with hole (13) in structure (10). Keep lugs about
1 inch off structure.
NOTE
Refer to Task 1-13, step 8, for re-use
of barrel nuts.
Before installing the forward
transmission assembly in the aircraft,
inspect the four mounting bolts (14) for
skip or continuous spiral score marks
on the bolt shank outside diameters.
Scoring is acceptable provided that
the score marks are not greater than
0.005 inch deep and/or no wider
than 0.060 inch wide. Any raised
material must be lightly polished. Use
crocus cloth (E122) to remove the
material from the bolt shanks. Also
inspect the four bushings (11.1) in
the transmission cover and the four
bushings (13.2) in the structure for
score marks and burrs. Lightly polish,
use crocus cloth (E122) to remove
any raised material.
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