TM 55-1520-240-23-1
1-92
INSPECTION (Continued)
1-92
REF.
NO.
AREA
NO.
FREQUENCY
INSPECTION REQUIREMENTS
24.
4, 5
AT TIME OF ENGINE REMOVAL FOR ANY REASON:
a. Forward airframe support engine mount lugs (visually) for cracks, nicks,
scratches, and elongated holes.
NOTE
The inspections in paragraph b and paragraph c are required at engine removal
only. Do not remove engines just to perform these inspections.
b. Remove the bolts through the spherical bearings. Remove the slip fit
bushings and the spherical bearings (do not remove the press fit bushings).
Fluorescent penetrant inspect or eddy current inspect forward airframe support
engine mount lugs. Check all parts for wear (Task 4-28). (Not required if it has
been performed in the last 600 hours of aircraft operation.)
c. Inspect engine drag link IAW Task 4-41. (Not required if it has been
performed in the last 600 hours of aircraft operation.)
24.1
4,5
WHEN A -714 SERIES ENGINE IS REMOVED FOR REPLACEMENT/OVERHAUL:
Download and print the digital engine control unit (DECU) to show the
total current engine operating hours and the total current cycles for the 3rd
compressor disk, 1st turbine disk, 2nd turbine disk, integral shaft assy (3rd
turbine disk), 4th turbine disk, 1st GP sealing plate, and GP spacer. Attach one
copy to the DA Form 2410 and one copy to the engine historical records. See
TM 1-2840-265-23 for instruction on downloading and resetting the DECU.
24.2.
4, 5
ANYTIME AN ENGINE IS INSTALLED:
a. On aircraft with T55-GA-714A engines only. Perform Aviation Vibration
Analyzer (AVA) check IAW TM 1-2840-265-23 and AVA procedures.
b. Update/reset the digital engine control unit (DECU) with the total current
engine operating hours and the total current cycles for the 3rd compressor disk,
1st turbine disk, 2nd turbine disk, integral shaft assy (3rd turbine disk), 4th
turbine disk, 1st GP sealing plate, and GP spacer. See TM 1-2840-265-23 for
instructions on downloading and resetting the DECU.
c. Retorque forward engine mount bolts after first flight. First flight not to
exceed 4 flight hours.
25.
4, 5
WHEN THE ENGINE OIL FILTER BUTTON IS EXTENDED:
Replace filter element and perform with Task 1-99, TM 55-2840-254-23-1.
26.
4, 5
WHEN EMERGENCY POWER REACHES 30 MINUTES CUMULATIVE TIME:
a. Perform engine hot end inspection. Record number of hot end inspections
on DA Form 2408-15. Record the computed elapsed time spent in emergency
power on DA Form 2408-15.
b. Record cumulative engine emergency power minutes, time since last hot end
inspection, and total engine operating hours on DA Form 2408-15.
27.
4, 5,
10
WHEN THE ENGINE OR TIMER/EMERGENCY POWER PANEL IS REMOVED OR INSTALLED:
a. Record the total reading on the digital timer for the installed engine on DA
Form 2408-15. Record next hot end inspection due on DA Form 2408-18.
b. Reset the black and white indicator flag using switch in nose compartment
while helicopter is on ground.
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Change 3
