±10 volts dc. The polarity of the ±10-volt dc process
back, an indication signal representing actual valve rod
position back to the remote control stations.
signal determines the direction of pitch change. The size
of the signal determines the rate of pitch change.
The ahead or astern pitch signal from remote
operating stations is fed directly to the electrohydraulic
In an LCAC, the purpose of the propeller pitch
servo control valve. The pitch signal routed to the
control system is to allow the operator to control the
speed and direction of the craft by changing the
e l e c t r o h y d r a u l i c servo control valve is directly
propeller pitch. The propeller is capable of forward or
proportionate to the amount of pitch desired. A linear
reverse pitch. The greater the angle of pitch, the faster
potentiometer is mounted on the pitch scale of the TCPI
the craft will move. The propellers are controlled by two
assembly. The mechanical arm indicator is also attached
control levers located on the left-hand console of the
to an actuating rod of a linear potentiometer. The
operator control station and yoke in and out movement.
function of the linear potentiometer is to transfer, or feed
(See fig. 5-26.)
Figure 5-26.--LCAC steering control station.