TM 1-1520-238-23
11-994
Change 6
11.232.
DIRECTIONAL CONTROL SYSTEM INSPECTION
11.232.7. -15, -17, -19, and -901 Swashplate Inspection (Phase Inspection Criteria).
a. Visually check outboard swashplate bearing seal for deterioration, contamination, or metal fragments.
(1) If seal is damaged or missing and/or metal fragments are present, replace swashplate assembly (para
11.262).
b. Remove tail rotor de-ice brush block from tail rotor swashplate (para 11.262).
c. Disconnect non-rotating swashplate from bellcrank (para 11.262).
d. Check bellcrank/clevis attachment holes for elongation.
(1) Maximum allowable elongation is 0.002 INCH.
(2) Maximum allowable clevis lug ID 0.4385 INCH (typical, 4 places).
(3) Maximum oversize or out–of–round bushing ID 0.313 INCH (typical, 2 places).
NOTE
The inspection is to provide for repeated rotation of the swashplate, thereby allowing the grease to
flow throughout the bearing. It is the nature of this new bearing to feel somewhat rough and sound
noisy until the grease has been distributed.
Under no circumstances rotate the swashplate in opposing directions. This purges the grease out of
the cage openings in the bearing, causing the balls to impact the cage walls which will produce a
noisy and rough feel. Usually a few rotations of the bearing will smooth out grease buildup in the
raceways of the bearing.
A slow light rotation of the swashplate will produce the same “ball-to-cage effect”. This will give the
bearing a rough or ratchety feel. Rotating the swashplate with a firm and quicker motion should
alleviate this occurrence.
e. Rotate the stationary swashplate with a firm and constant rotation in one direction only (the direction
of blade rotation).
(1) Perform this a minimum of six full 360 degree rotations.
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