The propeller pitch control system is composed of
a secondary CSEP channel maybe selected by using the
command and control keyboard. The control voltage
the yoke assembly, propeller pitch indicator, a control
supplied to the propeller pitch control has a positive to
u n i t , pitch levers, potentiometers, and amplifiers.
negative voltage range.
Pushing the yoke in or pulling it out will cause electrical
signals to be sent to the electrohydraulic servo valve and
actuator, which permits the operator to control the pitch
TROUBLESHOOTING CRP/CPP SYSTEMS
of the propellers. (Refer to fig. 5-27). An indicator at the
operator station provides an indication of propeller
For a GSE, familiarity with normal gauge readings
pitch.
and maneuvering times under varying conditions is
Electrical control signals for the propeller pitch
essential to troubleshooting electrohydraulic control
systems. Normal operating pressures will vary along
by moving the yoke in and out. The propeller pitch
with the following conditions:
levers set the center point for the plus and minus, in and
Changes in shaft speed
out, movement of the yoke. Inward movement causes a
p i t c h increase; outward movement causes a pitch
At every position change throughout the
decrease. Placing the propeller V PITCH switch in the
pitch-changing stroke
OFF position takes the yoke out of the propeller pitch
Between shaft sets because of manufacturing
control system. Propeller pitch is then controlled by the
tolerances
propeller pitch levers. The propeller pitch signals are
sent through the control systems electronic package
As an operator or maintenance technician, you
should avoid making any variations from these norms.
(CSEP) to the propeller. If a CSEP malfunction occurs,
Figure 5-27.--LCAC propeller pitch control system.
5-28
