mercoledì 26 novembre 2014

Avionic bending: Rudder Trim Position Indicator


The rudder position indicating system provides the flight crew with the amount of deflection of the rudder surface. This system does not include the rudder trim indication system. For information on the rudder and rudder trim control system

Component Details
Position Transmitter

The rudder position transmitter is mounted below the lower power control actuator. The transmitter's crank is attached to the rudder front spar by adjustable control rod. The position transmitter is clamped to a bracket mounted to a vertical fin rib 
Electrical power to the transmitter is controlled by the RUDDER POS circuit breaker on overhead circuit breaker panel P11.

Position Indicator

The rudder position indicator appears on the lower center display. The indicator scale in each direction is equal to 26 degrees.

The left power bus supplies 28 volts ac to the rotor in the transmitter, which is inductively coupled to the stator. The rotor is mechanically connected to the airplane control surface and rotates with the surface at the same time. Movement of the rudder changes the rotor position which in turn changes the stator output.This output signal is interpreted by computers and displayed on the flight deck. The control surface position is displayed on the lower center display.

The following video shows how the gauge behaves on power up and power down
This other video shows how the indicator behaves using a synchro transmitter moved manually