TM 55-1520-240-23-1
1-91
OVERHAUL AND RETIREMENT SCHEDULE (Continued)
1-91
NOTES
A.
Refer to table beginning on next page.
B.
Rotate horizontal pins and horizontal and vertical
pin bearings at 1200 hours.
C.
Horizontal Pins:
1.
If a pin has been shotpeened, it may be
operated an additional 1200 hours provided
it is rotated 180 . The following pins have
been shotpeened by the manufacturer:
1.
A356 thru A367
2.
A380 thru A403
3.
A440 and subsequent with "A"
prefix.
4.
YZ1 35 and subsequent with "YZ"
prefix 114R2197-7
Other pins have not been shotpeened unless
they have the letters "SP" (shotpeened)
etched next to their serial number. All pins
with part number 114R2196-6, 114R2197-5
or -6 also have been shotpeened.
2.
If a pin has not been shotpeened, it must be
replaced at 1200 hours.
D.
Do not use these transmissions if "FO" does
not appear following the S/N on the nameplate.
This part number transmission is an element of
the US Army Flight Safety Parts Surveillance
Program which requires the mandatory input of
these transmissions samples on a selected basis
at 500 hour intervals.
E.
Two separate DA Forms 2408-16, one for forward
transmission reporting on condition and one
for reporting RC retirement hours for forward
transmission rotor shaft.
F.
Compute hours from time of installation.
G.
Do not use servocylinders if the letter "A" does not
appear following the serial number on the metal
decal, installed during inspection/replacement of
eight (8) actuator screws, per SOF CH-47-93-02
(TB 1-1520-240-20-63). Contact the CH-47
Product Management Office for disposition
instructions DSN 693-1440 or commercial
314-263-1440.
H.
All overhauled actuators must have a suffix "N"
behind the serial number. (Suffix N indicates the
actuator has been adjusted in accordance with
TB 1-1520-240-20-85; this is not required on
new actuators.)
I.
The engine, gas turbine and hydro-mechanical
unit (HMU) TBO time limits are based on
operating hours from the digital engine control
unit (DECU) hours not aircraft flight hours.
See TM 1-2840-265-23 for instructions on
downloading and resetting the DECU.
J.
APU TBO based on 6000 events as obtained
from event meter attached to APU.
Change 3
1-331
