TM 1-1520-238-23
Change 7
5-231
5.51.
TAIL ROTOR ASSEMBLY INSPECTION
o. Check pitch horn bushing for galling and elongation.
(1) Elongation of inner diameter of bushings not to exceed 0.004 INCH.
p. Check pitch bearings for excessive wear.
(1) Allowable play not to exceed 0.25 INCH from tip to tip of opposing tail rotor blades.
5.51.4. Tail Rotor blade bearings Inspection
NOTE
This inspection will be also performed prior to removal of tail rotor swashplate for noisy or ratcheting
condition. This will be performed on all four tail rotor blade assemblies.
a. Inspect tail rotor blade bearings for pitch change force.
(1) Remove pitch control link from blade pitch horn (para 5.53).
(2) Attach spring scale to blade pitch horn. Pulling perpendicular to pitch arm, measure force required to rotate
blade on hub. Use scale.
(3) If force required is less than 25 pounds, install pitch control link on blade pitch horn (para 5.54) and
accomplish steps a.(1) and a.(2) for remaining blades.
(4) If force required is 25 pounds or more, repair or replace using the following procedures:
(a) Remove tail rotor blade (para 5.53).
(b) Clean contaminants from inside diameter of tail rotor inner and outer bearing sleeves, and tail rotor hub
bearing by lightly rubbing bearing surfaces. Use pad (item 130, App F).
(c) Wipe these bearing surfaces with clean, moistened cloth to remove any pad residue. Use cloth
(item 52, App F).
(d) Reinstall tail rotor blade (para 5.54) and perform pitch change force test (step a).
(e) If force required is less than 25 pounds, complete installation of pitch control link on blade pitch horn
(para 5.54).
(f) If force required is still 25 pounds or more, replace tail rotor blade (para 5.53).
END OF TASK
