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wings until a suitable taxi surface is reached. At any time
during this transition phase, before the weight of the aircraft
is being supported by the wheels and before the nosewheel
is on the surface, the pilot should be able to apply full power
and perform a safe takeoff (obstacle clearance and fi eld length
permitting) should the pilot elect to abandon the landing.
Once committed to a landing, the pilot should gently lower
the nosewheel to the surface. A slight reduction of power
usually helps ease the nosewheel down.
The use of brakes on a soft fi eld is not needed and should
be avoided as this tends to impose a heavy load on the nose
gear due to premature or hard contact with the landing
surface causing the nosewheel to dig in. The soft or rough
surface itself provides suffi cient reduction in the aircraft’s
forward speed. Often upon landing on a very soft fi eld, the
pilot needs to increase power to keep the aircraft moving and
from becoming stuck on the soft surface.
Power-on Approach and Landing for
Turbulant Air
Power-on approaches at an airspeed above the normal
approach speed should be used for landing in turbulent
air. This provides for more energy and positive control
of the aircraft when strong horizontal wind gusts, wind
sheer, or up and down drafts, are experienced. Like other
power-on approaches (when the pilot can vary the amount
of power), a coordinated combination of both speed and
power adjustments is usually required. It is easiest to think
of fl ying the aircraft onto the ground at an airspeed above
the stall speed. The additional power provides the pilot the
ability to reduce the descent rate to touch the wheels gently
to the surface at a higher speed. Landing in turbulent air is
where practice and experience in energy management are
utilized. This precise coordination of power and speed for
higher energy landings should fi rst be practiced in calm air
and can be used as the next step in learning landings after the
student becomes profi cient at low approaches.
To determine the additional approach speed to fl ying in
turbulence, one procedure is to use the normal approach
speed plus one-half of the wind gust factors. The wind gust
factor is determined by how much the airspeed varies while
fl ying. If the normal approach speed is 50 knots and the wind
gusts are at 15 knots, an airspeed of 57 knots is appropriate.
Another method is to ensure the aircraft is at least at VY speed
plus the wind gust factor. In any case, the airspeed that the
aircraft manufacturer recommends.
An adequate amount of power should be used to maintain the
proper airspeed and descent path throughout the approach
and the throttle retarded to idling position only after the
main wheels contact the landing surface. Care must be
exercised in not closing the throttle before the pilot is ready
for touchdown. In this situation, the sudden or premature
closing of the throttle may cause a sudden increase in the
descent rate that could result in a hard landing.
Landings from power-on approaches in turbulence should
be such that the touchdown is made with the aircraft in
approximately level fl ight attitude. The pitch attitude at
11-17
the ground track in the center of the runway and evaluate if
the landing should be completed, a go-around performed,
or a different landing location selected with more favorable
wind conditions.
Effects and Hazards of High Crosswinds for
Approaches and Landings
Figure 11-24 illustrates a scenario that includes the effects
and hazards of high wind, referencing groundspeed, high
rates of turn, and power requirements for making downwind
turns in close proximity to the ground.
During the downwind leg of the pattern, the pilot does not
notice the strong wind blowing the WSC aircraft into the
runway. From points A to W, the pilot reduces power as
normal but does not crab into the wind and drifts with the
wind toward the runway between points A and W. This leads
the pilot to be closer to the runway when he or she turns
onto base. The pilot turns onto base and is traveling at high
groundspeed and the strong tailwind leads to the pilot passing
the runway centerline normal fi nal approach at point X. From
points X to Y, the pilot starts the turn for fi nal approach late
because of the high groundspeed. The WSC aircraft past the
runway centerline leads the pilot to increase the bank to make
it back to the centerline. The previous errors lead the pilot
into a high bank angle at low altitude pointed down in a rapid
descent. This leads the pilot to apply full power at Y, which
　
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本文鏈接地址：Weight-Shift Control Aircraft Flying Handbook(123)