TM 55-1510-222-10
(5)
Set the desired altitude.
b.
Autopilot.
(1)
Autopilot controller UP TRIM, DN TRIM
annunciators Check not illuminated.
CAUTION
A steady illumination of UP TRIM or
DN TRIM annunciation indicates that
the automatic synchronization is not
functioning and the autopilot should
not be engaged.
(2)
Turn knob Center.
(3)
Elevator trim TM 55-1510-222-10 control
switch On.
(4)
Control wheel Hold to mid travel.
(5)
AP button Press. AP ENGAGE and YD
ENGAGE annunciators on autopilot controller will
illuminate. Servo clutches will engage.
WARNING
If the STBY annunciation 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
nonoperative 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.
(6)
Elevator trim follow-up Check.
(a)
Control wheel Hold aft of mid travel.
Trim wheel should run nose down after approximately 3
seconds. Trim down annunciation should illuminate after
approximately 8 seconds, and AP TRIM annunciation
should illuminate after approximately 13 seconds.
(b)
Control wheel Hold forward of mid
travel. Trim wheel should run nose up after
approximately 3 seconds, trim up annunciation should
illuminate after approximately 8 seconds, and AP TRIM
annunciation should
illuminate after approximately
13 seconds.
(7)
Turn controller Check that control wheel
follows in each applied direction, then center.
(8)
Pitch wheel Check that trim responds to
pitch wheel movement. (UP TRIM and DN TRIM
annunciators may illuminate).
(9)
Heading bug Center and engage HDG.
Check that control follows a turn in each direction.
(10)
Disengage AP by selecting GA. Check
that AP disengages and FD commands 7° nose up,
wings level attitude, and YD remains on.
c.
Electric elevator trim Check.
(1)
Elevator trim switch On.
(2)
Pilot and copilot trim switches Check
operation.
WARNING
Operation of the electric trim system
should occur only by movement of
pairs of switches. Any movement of
the
elevator
trim
wheel
while
depressing only one switch element
indicates a trim system malfunction.
The electric elevator trim control
switch must then be turned OFF and
flight conducted by operating the
elevator trim wheel manually. Do not
use autopilot.
(a)
Pilot and copilot. Check individual
element for no movement of trim, then check proper
operation of both elements.
(b)
Check
pilot
switches
override
copilot switches while trimming in opposite directions,
and trim moves in direction commanded by pilot.
(3)
Check pilot and copilot trim disconnects
while activating trim.
(4)
Elevator trim switch OFF then ON (ELEC
TRIM OFF annunciation extinguishes).
8.
Avionics Check and set as required.
9.
Flaps Check.
10.
Altimeters Set and check.
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