旋翼机飞行手册 ROTORCRAFT FLYING HANDBOOK

时间：2011-04-05 11:32来源：蓝天飞行翻译 作者：航空 点击：次

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Gyroplanes experience a slight lag between control input and aircraft response. This lag becomes more apparent during the sensitive maneuvering required for landing, and care must be taken to avoid overcorrecting for deviations from the desired approach path. After the turn to final, the approach airspeed appropriate for the gyroplane should be established. This speed is normally just below the minimum power required speed for the gyroplane in level flight. During the approach, maintain this airspeed by making adjustments to the gyroplane’s pitch attitude, as necessary. Power is used to control the descent rate.
Approximately 10 to 20 feet above the runway, begin the flare by gradually increasing back pressure on the cyclic to reduce speed and decrease the rate of descent. The gyroplane should reach a near-zero rate of descent approximately 1 foot above the runway with the power at idle. Low airspeed combined with a minimum of propwash over the tail surfaces reduces rudder effectiveness during the flare. If a yaw moment is encountered, use whatever rudder control is required to maintain the desired heading. The gyroplane should be kept laterally level and with the longitudinal axis in the direction of ground track. Landing with sideward motion can damage the landing gear and must be avoided. In a full-flare landing, attempt to hold the gyroplane just off the runway by steadily increasing back pressure on the cyclic. This causes the gyroplane to settle slowly to the runway in a slightly nose-high attitude as forward momentum dissipates.
Ground roll for a full-flare landing is typically under 50 feet, and touchdown speed under 20 m.p.h. If a 20
m.p.h. or greater headwind exists, it may be necessary to decrease the length of the flare and allow the gyroplane to touch down at a slightly higher airspeed to prevent it from rolling backward on landing. After touchdown, rotor r.p.m. decays rather rapidly. On landings where brakes are required immediately after touchdown, apply them lightly, as the rotor is still carrying much of the weight of the aircraft and too much braking causes the tires to skid.

SHORT-FIELD LANDING
A short-field landing is necessary when you have a relatively short landing area or when an approach must be made over obstacles that limit the available landing area. When practicing short-field landings, assume you are making the approach and landing over a 50-foot obstruction in the approach area.
To conduct a short-field approach and landing, follow normal procedures until you are established on the final approach segment. At this point, use aft cyclic to reduce airspeed below the speed for minimum sink. By decreasing speed, sink rate increases and a steeper approach path is achieved, minimizing the distance between clearing the obstacle and making contact with the surface. [Figure 20-14] The approach speed must remain fast enough, however, to allow the flare to arrest the forward and vertical speed of the gyroplane. If the approach speed is too low, the remaining vertical momentum will result in a hard landing. On a short-field landing with a slight headwind, a touchdown with no ground roll is possible. Without wind, the ground roll is normally less than 50 feet.

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