TM 55-1520-240-23-4
5-1
ROTARY-WING HEAD AND CONTROLS
(Continued)
5-1
LUBRICATION SYSTEM
A single hub oil tank lubricates the horizontal pin
bearings. Each pitch-varying housing has a pitch
bearing oil tank and two vertical pin bearing oil tanks.
The vertical pin tanks are connected to each other by an
oil manifold tube. Sight indicators are provided for each
tank, to check oil level. The swashplate is lubricated
with grease.
SELF-RETAINING BOLTS
Bolts connecting upper controls and shock absorbers
are the positive-retention or impedance types. These
bolts have a pawl or lock ring to keep the bolt in place,
even with the nut removed. Bolts are installed with bolt
heads facing the direction of rotation (Task 1-14).
END OF TASK
5-6