TM 1-1510-233-CL
P-12
15. RUDDER BOOST/YAW CONTROL TEST
switch – RUDDER BOOST. Check RUDDER
BOOST annunciator extinguished.
16. Electric elevator trim – Check.
a. ELEV TRIM switch – ON.
WARNING
Operation of the electric trim system
should occur only by movement of pairs
of switches. Any movement of the eleva-
tor trim wheel while depressing only
one switch element indicates a trim sys-
tem 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.
b. Pilot and copilot trim switches – Check indi-
vidual element for no movement of trim,
then check proper operation of both ele-
ments.
c. Pilot trim switches – Check that pilot
switches override copilot switches while
trimming in the opposite directions, and
trim moves in the direction commanded by
the pilot.
d. Pilot or copilot trim switches – Check trim
disconnects while activating pilot or copilot
trim disconnect switches.
e. ELEV TRIM switch – OFF, then ON (ELEV
TRIM OFF annunciator extinguishes).
