TM 55-1510-222-CL
e.
Set the desired altitude.
2.
Autopilot.
a.
Autopilot controller UP TRIM, DN TRIM annunciators - Check not illuminated.
CAUTION
A steady illumination of UP TRIM or DN TRIM annunciator indicates that the automatic
synchronization is not functioning and the autopilot should not be engaged.
b.
Turn knob - Center.
c.
Elevator trim control switch - ON.
d.
Control wheel - Hold to mid travel.
e.
AP button - Press. AP ENGAGE and YD ENGAGE annunciators on autopilot controller will illuminate.
Servo clutches will engage.
WARNING
If the STBY annunciator on the flight director mode selector does not illuminate within 10
seconds after the avionics master switch is turned on, the autopilot has failed self-test and is
considered non-operative and should not be used. The elevator trim system must not be
forced beyond the limits which are indicated on the elevator trim tab indicator.
f.
Elevator trim follow-up - Check.
(1) Control wheel - Hold aft of mid travel. Trim wheel should run nose down after approximately 3
seconds. Trim down annunciator should illuminate after approximately 8 seconds, and AP TRIM
annunciator should illuminate after approximately 13 seconds.
P-5
