曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
is not particularly dangerous if the airplane is kept
straight and a constant, safe pitch attitude is maintained.
The airplane will be approaching safe flying
speed rapidly and the advanced power will cushion any
secondary touchdown.
If the pitch attitude is increased excessively in an effort
to keep the airplane from contacting the runway, it may
cause the airplane to stall. This would be especially
likely if no trim correction is made and the flaps
remain fully extended. The pilot should not attempt to
retract the landing gear until after a rough trim is
accomplished and a positive rate of climb is established.
GROUND EFFECT
Ground effect is a factor in every landing and every
takeoff in fixed-wing airplanes. Ground effect can also
be an important factor in go-arounds. If the go-around
is made close to the ground, the airplane may be in the
ground effect area. Pilots are often lulled into a sense
of false security by the apparent “cushion of air” under
the wings that initially assists in the transition from an
approach descent to a climb. This “cushion of air,”
however, is imaginary. The apparent increase in airplane
performance is, in fact, due to a reduction in
induced drag in the ground effect area. It is “borrowed”
performance that must be repaid when the airplane
climbs out of the ground effect area. The pilot must
factor in ground effect when initiating a go-around
close to the ground. An attempt to climb prematurely
may result in the airplane not being able to climb, or
even maintain altitude at full power.
Common errors in the performance of go-arounds
(rejected landings) are:
• Failure to recognize a condition that warrants a
rejected landing.
• Indecision.
• Delay in initiating a go-round.
• Failure to apply maximum allowable power in a
timely manner.
• Abrupt power application.
• Improper pitch attitude.
• Failure to configure the airplane appropriately.
• Attempting to climb out of ground effect prematurely.
• Failure to adequately compensate for torque/Pfactor.
CROSSWIND
APPROACH AND LANDING
Many runways or landing areas are such that landings
must be made while the wind is blowing across rather
than parallel to the landing direction. All pilots should
be prepared to cope with these situations when they
arise. The same basic principles and factors involved
in a normal approach and landing apply to a crosswind
approach and landing; therefore, only the additional
procedures required for correcting for wind drift are
discussed here.
Crosswind landings are a little more difficult to perform
than crosswind takeoffs, mainly due to different
problems involved in maintaining accurate control of
the airplane while its speed is decreasing rather than
increasing as on takeoff.
There are two usual methods of accomplishing a crosswind
approach and landing—the crab method and the
wing-low (sideslip) method. Although the crab method
may be easier for the pilot to maintain during final
approach, it requires a high degree of judgment and
timing in removing the crab immediately prior to
touchdown. The wing-low method is recommended in
most cases, although a combination of both methods
may be used.
CROSSWIND FINAL APPROACH
The crab method is executed by establishing a heading
(crab) toward the wind with the wings level so that the
airplane’s ground track remains aligned with the centerline
of the runway. [Figure 8-15] This crab angle is
maintained until just prior to touchdown, when the
longitudinal axis of the airplane must be aligned with
the runway to avoid sideward contact of the wheels
with the runway. If a long final approach is being
flown, the pilot may use the crab method until just
before the roundout is started and then smoothly
change to the wing-low method for the remainder of
the landing.
Figure 8-15. Crabbed approach.
The wing-low (sideslip) method will compensate for a
crosswind from any angle, but more important, it
Ch 08.qxd 5/7/04 8:08 AM Page 8-13
PDF Create! 5 Trial
www.nuance.com
enables the pilot to simultaneously keep the airplane’s
ground track and longitudinal axis aligned with the
runway centerline throughout the final approach,
roundout, touchdown, and after-landing roll. This
prevents the airplane from touching down in a sideward
motion and imposing damaging side loads on
the landing gear.
To use the wing-low method, the pilot aligns the airplane’s
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址:
AIRPLANE FLYING HANDBOOK 飞机飞行手册上(88)