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
flying “behind the power curve.” At these speeds, as
pitch is increased to slow the gyroplane, more and more
power is required to maintain level flight. At the point
where maximum power available is being used, no
further reduction in airspeed is possible without initiating
a descent. This speed is referred to as the minimum
level flight speed. Because there is no excess power
available for acceleration, recovery from minimum level
flight speed requires lowering the nose of the gyroplane
and using altitude to regain airspeed. For this reason, it is
essential to practice slow flight at altitudes that allow
sufficient height for a safe recovery. Unintentionally
flying a gyroplane on the backside of the power curve
during approach and landing can be extremely
hazardous. Should a go-around become necessary,
sufficient altitude to regain airspeed and initiate a climb
may not be available, and ground contact may be
unavoidable.
Flight at slow airspeeds is usually conducted at airspeeds
5 to 10 m.p.h. above the minimum level flight
airspeed. When flying at slow airspeeds, it is important
that your control inputs be smooth and slow to prevent
a rapid loss of airspeed due to the high drag increases
with small changes in pitch attitude. In addition, turns
should be limited to shallow bank angles. In order to
prevent losing altitude during turns, power must be
added. Directional control remains very good while
flying at slow airspeeds, because of the high velocity
slipstream produced by the increased engine power.
Recovery to cruise flight speed is made by lowering
the nose and increasing power. When the desired speed
is reached, reduce power to the normal cruise power
setting.
COMMON ERRORS
1. Improper entry technique.
2. Failure to establish and maintain an appropriate
airspeed.
3. Excessive variations of altitude and heading
when a constant altitude and heading are
specified.
4. Use of too steep a bank angle.
5. Rough or uncoordinated control technique.
HIGH RATE OF DESCENT
A gyroplane will descend at a high rate when flown at
very low forward airspeeds. This maneuver may be
entered intentionally when a steep descent is desired,
and can be performed with or without power. An unintentional
high rate of descent can also occur as a result
0 20 40 85 Airspeed, MPH
Power Available
for Climb and
Acceleration
Power
Required
Engine Power
Available at
Full Throttle
Descent Rate of Climb
20 45 85
Power Required & Power Available vs. Airspeed Rates of Climb & Descent at Full Throttle
0 Airspeed, MPH
TYPICAL GYROPLANE
Horsepower
Minimum Level Flight Speed
Figure 20-13. The low point on the power required curve is the speed that the gyroplane can fly while using the least amount of
power, and is also the speed that will result in a minimum sink rate in a power-off glide.
20-13
of failing to monitor and maintain proper airspeed. In
powered flight, if the gyroplane is flown below minimum
level flight speed, a descent results even though
full engine power is applied. Further reducing the airspeed
with aft cyclic increases the rate of descent. For
gyroplanes with a high thrust-to-weight ratio, this
maneuver creates a very high pitch attitude. To recover,
the nose of the gyroplane must lowered slightly to
exchange altitude for an increase in airspeed.
When operating a gyroplane in an unpowered glide,
slowing to below the best glide speed can also result in
a high rate of descent. As airspeed decreases, the rate of
descent increases, reaching the highest rate as forward
speed approaches zero. At slow airspeeds without the
engine running, there is very little airflow over the tail
surfaces and rudder effectiveness is greatly reduced.
Rudder pedal inputs must be exaggerated to maintain
effective yaw control. To recover, add power, if available,
or lower the nose and allow the gyroplane to
accelerate to the proper airspeed. This maneuver
demonstrates the importance of maintaining the proper
glide speed during an engine-out emergency landing.
Attempting to stretch the glide by raising the nose
results in a higher rate of descent at a lower forward
speed, leaving less distance available for the selection
of a landing site.
COMMON ERRORS
1. Improper entry technique.
2. Failure to recognize a high rate of descent.
3. Improper use of controls during recovery.
4. Initiation of recovery below minimum recovery
altitude.
LANDINGS
Landings may be classified according to the landing
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：ROTORCRAFT FLYING HANDBOOK2(68)
