channel is operating, heading error signals are
added to a rate signal developed by the yaw rate
gyro. The resultant signal goes through the
channel monitor control panel as differential
current flow. The differential current flow
provides outputs to excite the yaw servo valve.
This signal also couples to the hover indicators.
As the servo valve corrects the heading error
signal through the auxiliary power piston and
rotary rudder blades, the heading error signal
diminishes. When the helicopter returns to its
reference heading, the compass system output
signals return to their original value. As the servo
valve corrects large heading error signals, it places
the yaw servo system in an open-loop condition.
The open-loop condition enables the yaw channel
to make larger heading corrections if necessary.
The pilot may override the open-loop operation
by applying an opposing force on the pedals.
If the pilot uses the pedals to turn manually
while ASE is engaged, an artificial force is felt,
which reduces the tendency to overcontrol. The
yaw rate gyro produces a signal proportional to
the turning rate of the helicopter. This rate signal
is eventually coupled to the servo valve and places
the yaw servo system in an open-loop condition,
opposite to the turn direction.
REVIEW SUBSET NUMBER 5
