TM 1-1520-238-23
1-402.18
Change 11
1.137.
SPECIAL INSPECTION CHECKLIST – continued
Helicopter Serial No.:
Date:
Area
No.
REQUIREMENT
EVERY
Item
Status
Special
Inspection
No.
6
47
10 HR/14 DAY MAIN ROTOR BLADE INSPECTION
a. Check Main Rotor Blade for cracks and voids (para 5.1).
4
48
6 MONTH TAIL ROTOR GEARBOX CURVIC COUPLING CORROSION
INSPECTION
a. Remove corrosion preventive compound from tail rotor gearbox curvic
coupling teeth/tail rotor head interface area.
b. Inspect area for corrosion. None allowed. If found, treat per para 1.49.
c. Apply corrosion preventive compound (item 62A, App F) to tail rotor
gearbox curvic coupling teeth/tail rotor head interface area.
1
49
EVERY 250 HOURS
a. Linear Variable Differential Transducer (LVDT) adjustment check (para.
11.216).
4
50
ANYTIME THE T/R HEAD IS REMOVED/REPLACED/REINSTALLED, THE
FOLLOW IS REQUIRED.
a. Recheck torque on the three (3) T/R fork nuts in accordance with
paragraph 50A.b.
b. If no rotation is found (no loss of torque), inspection is complete. If any
nut rotates, retorque the tail rotor fork nuts in accordance with para 5.61.
c. Recheck torque in accordance with para 50A.b. after next flight but not to
exceed 10 flight hours. If any nut rotates after the second torque check,
replace all three studs reference para 50A.c correction procedures. If no
loss of torque is detected, inspection is complete.
4
50A
EVERY 250 HOURS.
a. Inspection procedure.
NOTE
Inspection is performed on the aircraft with nothing disassembled. The
following 600 inch-pound torque check is only used to determine if the
studs are in a loose condition.
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