CSP
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902RFM207E
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1
Emergency and
Malfunction Procedures
ROTORCRAFT FLIGHT MANUAL
MD900 (902 Configuration with PW 207E)
FAA Approved
Reissue 2
Original
3
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19
3
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9.
FLIGHT CONTROL MALFUNCTIONS
ANTI-TORQUE FAILURE - GENERAL
Different types of failure require different techniques for optimum success in
recovery. It is not possible to identify all failure scenarios. However, under
standing the following general guidelines will assist the pilot in controlling the
aircraft.
Pilots facing an anti-torque system malfunction are presented with
variables in
types of failure as well as the operating environment at the moment of failure. There
fore, it is important that the pilot fully understand the effects and use of the remain
ing functional controls on establishing aircraft directional control.
Anti-torque malfunctions can be caused by jammed or broken thruster cone control
cable (fixed rotating cone), jammed fan linkage (fixed fan thrust), or total failure
of the NOTAR fan (complete loss of thrust).
Upon encountering an anti-torque system malfunction, the following general infor
mation may be applied by the pilot, when appropriate, to maintain directional control
of the aircraft.
Evaluate the extent of the condition by (1) applying pedal inputs to determine
the effect (if any) on aircraft yaw and (2) by reducing airspeed and noting
which direction the aircraft tends to yaw. If a pilot determines that a fixed
rotating cone condition exists, the pilot should place the pedals in a “neutral”
position (approximately one inch, [25mm] of right pedal). This “neutral” position
places the NOTAR fan at minimum pitch. Using pedal input in an attempt
to counter the yaw will produce an unfavorable thrust vector, increasing the
yaw.
Normally, the nose of the aircraft should turn right when power (collective)
is increased. Conversely, the nose of the aircraft should turn left when power
(collective) is reduced. The VSCS system will attempt to maintain “trimmed”
flight within its limited authority. When the collective is raised, the vertical
fins reposition to move the aircraft nose to the left. When the collective is
lowered, the vertical fins reposition to move the aircraft nose to the right,
assuming there is sufficient airflow (i.e., airspeed) across the vertical stabiliz
ers.
The effects of the VSCS can be neutralized by turning both VSCS switches
OFF. This action should only be accomplished with the aircraft established
on final approach and below 100 knots. This procedure is most helpful when
faced with a complete loss of thrust or with a fixed thruster - right pedal
applied condition.
Summary of Contents for MD900 Explorer
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