TM 55-1510-222-MTF
PROCEDURE
TROUBLESHOOTING
REFERENCE
A steady illumination of UP TRIM or DN
TRIM annunciator indicates that the auto-
matic synchronization is not functioning
and the autopilot should not be engaged.
(2) Turn knob - Center.
(3) Elevator
trim
switch - ON.
control
(3) Control wheel - Hold to
mid travel.
(5) AP button - Press. AP EN-
GAGE and YD ENGAGE
annunciators on autopilot
controller will illuminate.
Servo clutches will engage.
The autopilot system has a built-in test that
starts when the avionics master switch is
turned on. The autopilot is functional if the
STBY annunciator light on the autopilot
mode selector is illuminated within 10 sec-
onds. If not. the system is considered non-
operative and should not be used. (However,
if the STBY annunciator light does not illu-
minate, the autopilot/yaw damper will not
engage.) The elevator trim system must not
be forced beyond the limits which are indi-
cated on the elevator trim tab indicator.
(6) Elevator trim follow-up -
Check as follows:
2-25
