TM 55-1510-219-MTF
PROCEDURE
TROUBLESHOOTING
REFERENCE
BEFORE TAXIING (CONT)
a. Pilot's and copilot's PITCH TRIM
switches - Press to NOSE UP and NOSE
DN positions, singularly and in pairs.
Check that trim wheel moves in proper
direction and operates only when trim
switches are pressed in pairs. Any
deviation requires that electric elevator
trim be turned off and flight conducted
using manual trim.
b. DISC TRIM switch - Press to second
detent and verify that electric trim
disconnects and ELEV TRIM annunciator
light (in pedestal) extinguishes.
c. Flight director (FDI) and Radio Magnetic
Indicator (RMI) warning flags - Check
masked.
NOTE
Since the pressure of airflow that normally opposes
movement of control surfaces is absent during preflight check,
it is possible to get a hard over control surface deflection if an
autopilot command is allowed to remain active for any
appreciable length of time. Move turn knob and pitch
thumbwheel only enough to check operation, then return them
to the center position.
d. Autopilot mode selector panel Select HDG mode.
e. Horizontal Situation Indicator (HSI) - Set
heading marker under lubber line.
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