9.9.5 Tail Rotor Fixed Pitch Malfunction.
pitch failure may be evident by slow, intermittent, or no
response to pedal input or no pedal movement. A left or
right yaw may be apparent.
a. In Ground Effect. If a failure occurs during in-
ground-effect hover, reaction may vary from adjusting
collective and PWR levers during a left rotation to acti-
vating the CHOP collar to stop a right rotation. In any
case, the primary concern should be to land the aircraft
with as little yaw rate as possible.
1. If the aircraft has an uncontrolled turn to the
left, a reduction in the PWR levers coordinated
with an increase in collective may slow or stop
the rotation so that a controlled power on de-
scent to landing can be accomplished.
2. If the aircraft is not turning, a slight reduction in
collective pitch will begin a descent. During the
descent, a slight rotation to the left may be
present; increasing collective just prior to
touchdown should stop the rotation.
3. If the aircraft has an uncontrolled turn to the
right, reduce collective to begin descent. At
approximately 5 to 10 feet AGL perform a hov-
ering autorotation by CHOP Collar CHOP or
PWR Levers OFF.
b. Out-Of-Ground Effect.
1. If little or no right rotation or if left rotation is ex-
perienced and control can be maintained, the
aircraft should be accelerated into forward
flight and perform approach and landing ap-
propriate to power setting and condition of
flight at time of failure.
2. If the aircraft cannot be accelerated into for-
ward flight, initiate a power-on descent. Col-
lective should be adjusted so that an accept-
able compromise between rate of turn and
rate of descent is maintained. At approximate-
ly 5 to 10 feet above touchdown, perform a
hovering autorotation by CHOP Collar
CHOP or PWR Levers OFF.
9.9.6 Main Transmission Input Drive Clutch Fail-
ure. An input drive clutch malfunction is most likely to
occur during engine start or when an engine power lever
is advanced. Indications may include: erratic torque in-
dication on the affected engine, or a complete loss of
torque indication on the affected engine, and/or Np of
the affected engine exceeding Nr. If the failure is a sud-
den disengagement, the torque of the opposite engine
will double as it attempts to carry the load. A sudden
high torque input drive clutch engagement may cause
severe engine and/or drive train damage. A sudden en-
gagement is indicated by a loud noise and/or a sudden
increase in engine torque. Should an input drive clutch
fail to engage, perform the following:
When clutch fails to disengage, dam-
age to the affected engine will result
(due to lack of oil pressure) if both
engines are not shut down simulta-
When clutch fails to engage, do not
shut down both engines simulta-
neously. Damage may result if there is
a. In Flight.
1. PWR lever (affected engine) IDLE.
If Np of the affected engine is below Nr
(indicating the clutch is disengaged):
2. EMER ENG SHUTDOWN (affected engine).
3. LAND AS SOON AS PRACTICABLE.
If Np of the affected engine is not below Nr
(indicating the clutch has failed to disengage):
4. LAND AS SOON AS POSSIBLE
5. EMER ENG SHUTDOWN (both engines
b. On Ground (with indications that a clutch has
failed to engage).
1. EMER ENG SHUTDOWN (affected engine
2. Check NG is less than 10% (affected engine)
3. Perform normal engine shutdown.