system, such as a s evered driveshaft, causing the tail
rotor to lose power.
a. P
owered Flight.
(1) Indi cations:
(a) Abnormal vibrations.
(b) Pedal input has no effect on helicopter
trim.
(c) Nose of th e helicop ter t urns to the right
(left sideslip).
(d) Left roll of the fuselage along the longitu-
dinal axis.
Degree of roll and sideslip may be varied by
varying throttle and/or collective (At airspeeds
below 40 knots in powered fl ight, the sideslip
may become uncontrollable, and the helicopter
will begin to spin on the vertical axis. Autorota-
tion may be t he only option).
(2) P
rocedures.
(a) Continue powered flight, if possible, to a
suitable landing area at or above minimum rate of de-
scent airspeed.
(b) A
UTOROTATE when land ing area is
reached .
1
Ifarun-onlandingispossible,complete
autorotation with a touchdown airspeed as required for
directional control.
2
If a run-on landing is not possible, start
to decelerate from about 75 feet altitude, so that for-
ward ground speed is at a minimum when the helicopter
reaches 10 to 20 feet. Execute touchdown with a rapid
collective pull just prior to touchdown in a level attitude
with minimum ground speed.
b. Deleted.
9-20. FIXE D PITCH SETTINGS. T h is is a malfunc-
tion involving a loss of control resulting in a fixed pitch
setting. Whether the nose of the helicopter yaws left or
right is dependent upon the amount of pedal applied at
the time of the malfunction. Regardless of pedal setting
at the time of malfunction , a varying amount of tail rotor
thrust will be delivered at all times during flight.
a. R
educed power (low torque).
(1) Indications: The nose of the helicopter will
turn right when power is applied.
(2) P
rocedure:
(a) If helicopter control can be maintained in
powered flight, the best solution is to maintain control
with power and accomplish a run-on landing as soon as
practicable.
(b) If helicopter control cannot be main-
tained, close the throttle immediately and accomplish
an autorotational landing.
b. I
ncreased p o wer (high torque).
(1) Indications: The nose of the helicopter will
turn left when power is reduced.
(2) P
rocedure:
(a) Maintain control with power and air-
speed. (Between 40 and 70 knots.)
(b) If needed, reduce engine RPM manually
to 98%.
(c) Continue powered flight to a suita ble
landingareawherearun-onlandingcanbeaccom-
plished.
(d) Execute a run-on landing with power and
a touchdown speed which will minimize sideslip. Use
throttle and collective, as necessary, to control sideslip
and heading.
c. H
over.
(1) Indication: Helicopter heading cannot be
controlled with pedals.
(2) P
rocedure.
(a) Fixed pedal - Land.
(b) Loss of t ail rotor thrust - Perform hovering
autorotation.
9-21. LOSS OF TAIL ROTOR COMPONENTS. The
severity of this situation is dependent upon the amount
of weigh t lost. A ny loss of this nature will re su lt in a
forward center of grav ity shift, requiring aft cyclic.
a. I
ndications:
9-8 Change 14
TM 55-1520-228-10
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