HEADQUARTERS OH-58A, Technical Manual

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system, such as a severed driveshaft, causing the tail
rotor to lose power.
a. Powered Flight.
(1) Indications:
(a) Abnormal vibrations.
(b) Pedal input has no effect on helicopter
trim.
(c) Nose of the helicopter turns 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 the only option).
(2) Procedures.
(a) Continue powered fl ight, if possible, to a
suitable landing area at or above minimum rate of de-
scent airspeed.
(b) AUTOROTATE when landing area is
reached.
1 If a run-on landing is possible, 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. FIXED PITCH SETTINGS. This is a malfunc-
tion involving a loss of control resulting in a fi xed 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 fl ight.
a. Reduced power (low torque).
(1) Indications: The nose of the helicopter will
turn right when power is applied.
(2) Procedure:
(a) If helicopter control can be maintained in
powered fl ight, 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. Increased power (high torque).
(1) Indications: The nose of the helicopter will
turn left when power is reduced.
(2) Procedure:
(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 fl ight to a suitable
landing area where a run-on landing can be accom-
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. Hover.
(1) Indication: Helicopter heading cannot be
controlled with pedals.
(2) Procedure.
(a) Fixed pedal - Land.
(b) Loss of tail rotor thrust - Perform hovering
autorotation.
9-21. LOSS OF TAIL ROTOR COMPONENTS. The
severity of this situation is dependent upon the amount
of weight lost. Any loss of this nature will result in a
forward center of gravity shift, requiring aft cyclic.
a. Indications:
9-8 Change 14
TM 55-1520-228-10