b. Measure distance that either bellcrank end
moves. If a bellcrank moves more than 3/8
inch, there is excess looseness in this
portion of control system.
c. Isolate cause of excess looseness. (Refer
to TM 55-1520-240-23, Ch. 11.)
F. ROTOR PHASING.
Improper phasing can result in injury to per-
sonnel and serious damage to helicopter.
Whenever the rotary-wing system has been
dephased or components of the drive system
(except the engine drive shafts or engine
XMSNs) have been removed or discon-
nected, the system must be properly phased
before the system is operated. The method of
checking or obtaining proper phase relation-
ship of the rotors is given in the above refer-
Phasing requires alignment of the swiveling
actuators with the rotating swashplates. Do
not perform any alignments using pivoting
actuators. The swiveling actuator on the for-
ward rotor is located on the left side of the
swashplate and the swiveling actuator on the
aft rotor is on the right side of the swashplate.