Emergency and
Malfunction Procedures
CSP–520N–1
MD 520N (500N) ROTORCRAFT FLIGHT MANUAL
R
Original
3–21
FAA Approved
CYCLIC TRIM FAILURE
Indications:
Inability to reduce cyclic forces with the cyclic trim switch. The failure will
be one of the following types.
Control of the helicopter is the primary consideration of a pilot
confronted with any type of trim motor or switch malfunction. The
pilot–in–command should land the helicopter immediately if the
pilot’s physical condition, strength, or threshold of fatigue, would
compromise their ability to safely control the helicopter in
continued flight.
Indications:
Inoperative trim
Conditions:
The trim motor fails to respond to application of the cyclic trim switch in
one or more directions.
Procedures:
F
Establish a safe flight condition that produces the least cyclic control
force. Normally straight and level at the last trimmed airspeed.
F
Actuate the trim switch thru all positions in an attempt to restore trim
capability and determine the extent of trim failure. If restored, trim to a
near neutral position and land as soon as practical avoiding further trim
ming.
F
If trim failure is determined to be in all directions, and control of the he
licopter can be maintained safely, check/reset TRIM circuit breaker.
F
Land as soon as practical if unable to re−establish full cyclic trim control
with the pilot’s cyclic.
WARNING
