TM 55-1520-240-23-4
5-1
ROTARY-WING HEAD AND CONTROLS
(Continued)
5-1
Three pitch links are installed on each rotary-wing head.
Forward and aft pitch links are similar except for the
angle between rod ends. Each pitch link is adjustable
to change the pitch of an individual blade. Moving the
turnbuckle toward the + mark makes the pitch link longer
and increases blade pitch. A turn in the - direction
shortens the pitch link and decreases blade pitch.
DRIVE COLLAR AND DRIVE ARMS
The drive collar transmits torque to the swashplate
through the upper and lower drive arms. The drive
arms are hinged to allow the swashplate to slide up
and down on the slider shaft. The splined drive collars
mate with splines on the transmission rotor shafts. A
flange is located on the drive collar for installation of the
weather-protective cover. Drive collar lugs are provided
for connecting the upper drive arm. The upper drive arm
is connected at the other end to the lower drive arm.
Both connections are hinged. A ball spherical bearing
on the lower drive arm is connected to the swashplate.
This arrangement allows swashplate to tilt.
WEATHER-PROTECTIVE COVER
The weather-protective cover is bolted to the drive collar
flange and turns with the collar and shaft. The cover
provides weather-protection for the upper controls.
Flexible boots protect the upper portion of the pitch links
where they pass through the cover.
5-5
