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

W
RUNWAY
Figure 11-24. Crosswind procedures and effects/hazards of high crosswinds.
11-19
25
FINAL APPROACH ROUND OUT TAXI
TOUCH
DOWN
Wind
Figure 11-25. Crosswind approach and landing.
Crosswind Landings
When in fi nal approach, the wind correction angle (crab
angle) is established by heading toward the wind with the
wings level so that the aircraft’s ground track remains aligned
with the centerline of the runway. [Figure 11-25] This crab
angle is maintained all the way to touchdown, when the rear
wheels hit fi rst and rotate the carriage and wing around so
the front wheel touches the ground with the carriage going
straight. However, if in turbulent air or pitched forward
during the touchdown, with the front wheel touching the
ground fi rst, the pilot should lightly control the steering of
the front wheel to be headed in the direction the carriage is
going. WSC carriage front landing gear typically has camber
that tends to steer the front wheel naturally in the direction
of travel, so a light touch on the front wheel as it touches
the ground allows it to fi nd its own direction of travel. Once
the front wheel is on the ground, lower the nose to keep the
WSC on the ground and steer as required down the center
of the runway.
The procedure for the wing during the roundout is the same
as that for normal and turbulent roundout and touchdowns.
The exception is that after touchdown the windward wing
should be lowered slightly so the wind cannot get under it to
fl ip the WSC aircraft during later landing roll and taxi.
Maximum Crosswind Velocities
Takeoffs and landings in certain crosswind conditions are
inadvisable and even dangerous. [Figure 11-26] If the
crosswind is great enough, a hazardous landing condition
may result. Therefore, takeoff and landing capabilities with
respect to the reported surface wind conditions and available
landing directions must be considered.
WSC crosswind limitations have been tested and are included
in the POH. The headwind and crosswind components for a
given situation can be determined by reference to a crosswind
component chart. [Figure 11-27] It is imperative that pilots
determine the maximum crosswind component of each aircraft
fl own and avoid operations in wind conditions that exceed the
capability of the aircraft. The automatic weather observation
system (AWOS) or automatic surface observation system
(ASOS) at airports is useful in determining the measured
velocity for this evaluation.
Common errors in the performance of crosswind approaches
and landings include:
• Failure to recognize a strong crosswind blowing at the
runway during the downwind leg;
11-20
Figure 11-28. Pilot view of runway where a steep approach would
be required.
Wind Velocity—MPH
30
20
10
0
Wind Angle—Degrees
20° 40° 60° 80° 100° 110°
DANGER ZONE
Direct Headwind
Direct Crosswind
Figure 11-26. Example of a crosswind limitations chart.
EXAMPLE
15-knot wind at
50° to runway is
12-knot crosswind
component and
10-knot headwind
component
15 knot wind
50°
15 knot wind
12 knots
10 knots
Headwind Component in Knots or MPH
30
25
20
15
10
5
0
Crosswind Component in Knots or MPH
5 10 15 20 25 30
10°
20°
30°
40°
50°
60°
70°
90°
80°
0°
WIND VELOCITY
WIND SPEED 15
Direct Headwind
Direct Crosswind
12
Figure 11-27. Example of a crosswind component chart.
• Inadequate compensation for wind drift on the
turn from base leg to fi nal approach, resulting in
undershooting or overshooting;
• Inadequate compensation for wind drift on final
approach;
• Unstabilized approach;
• Touchdown while drifting;
• Excessive pressure on the nosewheel steering during
touchdown;
• Excessive airspeed on touchdown;
• Failure to apply appropriate fl ight control inputs during
rollout;
• Failure to maintain direction control on rollout; and
• Excessive braking.
Steep Approaches
A steep approach is a valuable maneuver for WSC aircraft.
[Figure 11-28] It is better to be too high for an approach
rather than too low for an approach in case the engine fails. A
steep approach can be used to reach the landing point easily;
if too low, the aircraft lands short. Steep approaches are used
　
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：Weight-Shift Control Aircraft Flying Handbook(125)