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.
Pilot and copilot trim switches - Check individual
element for no movement of trim, then check
proper operation of both elements.
Pilot trim switches - Check that pilot switches
opposite directions, and trim moves in direction
commanded by pilot.
Pilot or copilot trim switches - Check trim
disconnects while activating pilot or copilot trim
ELEV TRIM switch - OFF then on (ELEC TRIM
OFF annunciator extinguishes).
ASE/ACS BIT CHECKS
UTIL on MFD - Depress.
System BIT (R1) - Depress.
Before conducting the INS BIT ensure mode
selector is in ALIGN and align state is 8 or
lower, but before mode selector is placed in
INS BIT - Perform as follows:
INS - Select on EHSI by depressing INS/TCN on
INS - Select on single needle bearing source
selector switch on display controller.