曝光臺 注意防騙 網曝天貓店富美金盛家居專營店坑蒙拐騙欺詐消費者

• Pulling the control yoke aft to attain and maintain
attitude.
• Releasing back pressure to lower the nose and
increasing back pressure to raise the nose.
• Increasing back pressure to flare for landing.
Trim mechanisms can be useful in the event of an
in-flight primary control failure. For example, if the
linkage between the cockpit and the elevator fails in
flight, leaving the elevator free to weathervane in the
wind, the trim tab can be used to raise or lower the
elevator, within limits. The trim tabs are not as effective
as normal linkage control in conditions such as
low airspeed, but they do have some positive effect—
usually enough to bring about a safe landing.
If an elevator becomes jammed, resulting in a total loss
of elevator control movement, various combinations of
power and flap extension offer a limited amount of
pitch control. A successful landing under these conditions,
however, is problematical.
LANDING GEAR MALFUNCTION
Once the pilot has confirmed that the landing gear has
in fact malfunctioned, and that one or more gear legs
refuses to respond to the conventional or alternate
methods of gear extension contained in the AFM/POH,
there are several methods that may be useful in
attempting to force the gear down. One method is to
dive the airplane (in smooth air only) to VNE speed (red
line on the airspeed indicator) and (within the limits of
safety) execute a rapid pull up. In normal category
airplanes, this procedure will create a 3.8 G load on the
structure, in effect making the landing gear weigh 3.8
times normal. In some cases, this may force the landing
gear into the down and locked position. This
procedure requires a fine control touch and good feel
for the airplane. The pilot must avoid exceeding the
design stress limits of the airplane while attempting to
lower the landing gear. The pilot must also avoid an
accelerated stall and possible loss of control while
attention is directed to solving the landing gear
problem.
Another method that has proven useful in some cases
is to induce rapid yawing. After stabilizing at or
slightly less than maneuvering speed (VA), the pilot
should alternately and aggressively apply rudder in one
direction and then the other in rapid sequence. The
resulting yawing action may cause the landing gear to
fall into place.
If all efforts to extend the landing gear have failed, and
a gear up landing is inevitable, the pilot should select
an airport with crash and rescue facilities. The pilot
should not hesitate to request that emergency equipment
be standing by.
When selecting a landing surface, the pilot should consider
that a smooth, hard-surface runway usually
causes less damage than rough, unimproved grass
strips. A hard surface does, however, create sparks that
can ignite fuel. If the airport is so equipped, the pilot
Ch 16.qxd 5/7/04 10:30 AM Page 16-9
16-10
can request that the runway surface be foamed. The
pilot should consider burning off excess fuel. This will
reduce landing speed and fire potential.
If the landing gear malfunction is limited to one main
landing gear leg, the pilot should consume as much
fuel from that side of the airplane as practicable,
thereby reducing the weight of the wing on that side.
The reduced weight makes it possible to delay the
unsupported wing from contacting the surface during
the landing roll until the last possible moment.
Reduced impact speeds result in less damage.
If only one landing gear leg fails to extend, the pilot
has the option of landing on the available gear legs, or
landing with all the gear legs retracted. Landing on
only one main gear usually causes the airplane to veer
strongly in the direction of the faulty gear leg after
touchdown. If the landing runway is narrow, and/or
ditches and obstacles line the runway edge, maximum
directional control after touchdown is a necessity. In
this situation, a landing with all three gear retracted
may be the safest course of action.
If the pilot elects to land with one main gear retracted
(and the other main gear and nose gear down and
locked), the landing should be made in a nose-high
attitude with the wings level. As airspeed decays, the
pilot should apply whatever aileron control is necessary
to keep the unsupported wing airborne as long as
possible. [Figure 16-7] Once the wing contacts the
surface, the pilot can anticipate a strong yaw in that
direction. The pilot must be prepared to use full
opposite rudder and aggressive braking to maintain
some degree of directional control.
　
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：AIRPLANE FLYING HANDBOOK 飛機飛行手冊下(97)