TM 1-1520-238-23
Change 11
1-402.21
1.137.
SPECIAL INSPECTION CHECKLIST – continued
Helicopter Serial No.:
Date:
Area
No.
Special
Inspection
No.
REQUIREMENT
EVERY
Item
Status
4
50A
(cont)
(10) Check spline teeth on both the tail rotor fork and drive shaft for
sealant. Remove sealant if present. Do not reapply sealant.
(11) If none of the conditions identified in paragraph A50A.b(9) through
A50A.b.(10) exists, apply CPC MIL-C-16173 to studs and install the
T/R head. Make sure that the number 1 studs and hole defined in
paragraph 50A.c.(1).
(12) Recheck torque in accordance with paragraph 50A.e(6).
e. Correction Procedures.
(1) Remove T/R gearbox from the aircraft in accordance with Task 6.145.
(2) Contact local OLR site to replace all three T/R gearbox output shaft
studs.
(3) After the T/R gearbox is returned from the OLR site, reinstall the
gearbox per Task 6.145.
NOTE
The Task in paragraph 50A.e.(3) will require three persons and an
overhead crane/hoist. Do not endload the studs.
(4) Apply corrosion preventive compound, MIL-C-116173, Grade IV to
studs.
(5) Install the T/R head, ensuring that the number 1 fork hole and stud
established in paragraph 50A.d.(1).
(6) Recheck torque on the three (3) T/R fork nuts in accordance with
paragraph 50A.b.
(a) 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
paragraph 5.61.
(b) Recheck torque in accordance with paragraph 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. If no loss is detected,
inspection is complete.
(c) Repeat torque check at each 250 hour phase inspection.
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