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时间:2010-05-09 10:13来源:1 作者:admin
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

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8-10
The closer the airplane gets to the runway, the larger
(and possibly more frequent) the required corrections
become, resulting in an unstabilized approach.
Common errors in the performance of normal
approaches and landings are:
• Inadequate wind drift correction on the base leg.
• Overshooting or undershooting the turn onto
final approach resulting in too steep or too shallow
a turn onto final approach.
• Flat or skidding turns from base leg to final
approach as a result of overshooting/inadequate
wind drift correction.
• Poor coordination during turn from base to final
approach.
• Failure to complete the landing checklist in a
timely manner.
• Unstabilized approach.
• Failure to adequately compensate for flap extension.
• Poor trim technique on final approach.
• Attempting to maintain altitude or reach the runway
using elevator alone.
• Focusing too close to the airplane resulting in a
too high roundout.
• Focusing too far from the airplane resulting in a
too low roundout.
• Touching down prior to attaining proper landing
attitude.
• Failure to hold sufficient back-elevator pressure
after touchdown.
• Excessive braking after touchdown.
INTENTIONAL SLIPS
A slip occurs when the bank angle of an airplane is too
steep for the existing rate of turn. Unintentional slips
are most often the result of uncoordinated
rudder/aileron application. Intentional slips, however,
are used to dissipate altitude without increasing airspeed,
and/or to adjust airplane ground track during a
crosswind. Intentional slips are especially useful in
forced landings, and in situations where obstacles must
be cleared during approaches to confined areas. A slip
can also be used as an emergency means of rapidly
reducing airspeed in situations where wing flaps are
inoperative or not installed.
A slip is a combination of forward movement and
sideward (with respect to the longitudinal axis of the
airplane) movement, the lateral axis being inclined
and the sideward movement being toward the low
end of this axis (low wing). An airplane in a slip is in
fact flying sideways. This results in a change in the
direction the relative wind strikes the airplane. Slips
are characterized by a marked increase in drag and
corresponding decrease in airplane climb, cruise, and
glide performance. It is the increase in drag, however,
that makes it possible for an airplane in a slip to
descend rapidly without an increase in airspeed.
Most airplanes exhibit the characteristic of positive
static directional stability and, therefore, have a natural
tendency to compensate for slipping. An intentional
slip, therefore, requires deliberate cross-controlling
ailerons and rudder throughout the maneuver.
A“sideslip” is entered by lowering a wing and applying
just enough opposite rudder to prevent a turn. In a
sideslip, the airplane’s longitudinal axis remains parallel
to the original flightpath, but the airplane no
longer flies straight ahead. Instead the horizontal
component of wing lift forces the airplane also to
move somewhat sideways toward the low wing.
[Figure 8-12] The amount of slip, and therefore the
rate of sideward movement, is determined by the bank
angle. The steeper the bank—the greater the degree of
slip. As bank angle is increased, however, additional
opposite rudder is required to prevent turning.
A “forward slip” is one in which the airplane’s
direction of motion continues the same as before the
slip was begun. Assuming the airplane is originally
in straight flight, the wing on the side toward which
Direction of Movement
Relative Wind
Sideslip
Figure 8-12. Sideslip.
Ch 08.qxd 5/7/04 8:08 AM Page 8-10
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the slip is to be made should be lowered by use of the
ailerons. Simultaneously, the airplane’s nose must be
yawed in the opposite direction by applying opposite
rudder so that the airplane’s longitudinal axis is at an
angle to its original flightpath. [Figure 8-13] The
degree to which the nose is yawed in the opposite
direction from the bank should be such that the
original ground track is maintained. In a forward slip,
the amount of slip, and therefore the sink rate, is
determined by the bank angle. The steeper the bank—
the steeper the descent.
In most light airplanes, the steepness of a slip is
limited by the amount of rudder travel available. In
 
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