TM 1-1520-238-23
Change 11
1-402.25
1.137.
SPECIAL INSPECTION CHECKLIST – continued
Helicopter Serial No.:
Date:
Area
No.
Special
Inspection
No.
REQUIREMENT
EVERY
Item
Status
5
53
(cont)
50 HOURS
CLEAN DEBRIS FROM THE COVERED PORT.
a. Remove one screw from clutch name plate and loosen remaining screw.
b. Using a small probe, clean debris from the covered port.
c. Inspect friction disk area for oil. None Allowed. If found replace PTO
clutch.
d. Reinstall removed screw in nameplate and tighten both screws.
5
53A
50 HOURS
a. Check APU PTO clutch for heat discoloration.
NOTE
Heat discoloration is usually confined to the duplex
bearing housing area.
Check APU PTO clutch for heat discoloration. None Allowed.
b. Check PTO clutch for corrosion.
Inspect PTO clutch for corrosion. None Allowed.
c. Check APU PTO clutch for cracks.
Inspect APU PTO clutch for cracks. None Allowed. If cracks are suspected
perform nondestructive inspection (TM 1-1520-264-23).
5
54
50 HOURS
INSPECT THE DUPLEX BEARING AREA.
a. Inspect the output bearing grease seal for damage and/or metal
contamination. None Allowed.
b. Manually rotate the clutch output shaft in both directions. The rotation
should be smooth with no roughness or binding. A light amount of drag,
caused by the shaft seal is to be expected.
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