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4. Throttle may have to be adjusted in some piston engine helicopter to maintain RPM throughout the takeoff.
It is important that your eyes be focussed outside on normal hover references. Glance quickly in at the console to monitor engine instruments.
HOVER CHECK
Immediately after the aircraft is in the low hover (approximately 6 inches) a “hover check” is completed, then proceed to normal hover height. The check may vary with helicopter type, but must include the following items:
1. ensure the centre of gravity is in limits, by observing cyclic stick position;
2. note the power required to hover, and the power available for flight; and
3. check that control response is normal.
THE LANDING
A normal landing is initiated from a 3 to 5 foot hover with the helicopter facing into the wind if possible.
The controls are used as follows:
1. cyclic to maintain position over the ground;
2. collective to control rate of descent; and
3. pedals to control helicopter heading.
It is important that you start the landing from a stable hover. From the hover, start a slow rate of descent with collective. As the helicopter approaches the ground, you will have to lower the collective slightly more to compensate for increased ground effect. Throughout the descent, heading and hover position are maintained with pedals and cyclic. For safety reasons, it is important that the helicopter does not touch down with sideward or rearward drift to avoid dynamic rollover. As the helicopter skids touch the ground, continue to slowly lower the collective to flat pitch, and then centralize the cyclic and pedals. Remember that the left skid will touch the ground first for North American produced helicopters and vice versa for French helicopters.
If you have problems maintaining control during the landing, smoothly climb back to a normal hover, then stabilize the hover prior to initiating another landing.
EXERCISE 10 - HOVERING EXERCISES
In this exercise you will learn how to perform the following manoeuvres:
1. turns at the hover; and
2. hover-taxiing.
Manoeuvring close to the ground is very much part of the helicopter environment and you will find that these manoeuvres are carried out as a matter of course.
During the exercise, bear in mind the following airmanship points to include that you:
1. ensure the manoeuvring area is flat and free of any obstacles that could present a hazard to the tail rotor;
2. monitor the engine instruments to ensure that no limitations are exceeded; and
3. anticipate the effect of wind.
PEDAL TURNS AT THE HOVER (TURNS AROUND THE MAST)
Begin your pedal turns from a stable hover, preferably with the helicopter facing into wind. Look out to ensure the surrounding area through which the tail rotor will pass is clear of obstacles that could present a hazard. Start the turn by applying pedal to rotate the helicopter in the desired direction: to turn left apply left pedal, to turn right apply right pedal. Control the rate of the turn with pedal; that is: less left pedal to reduce the rate of a left turn, and vice versa. The amount of pedal required will vary with the strength of the wind. To stop the turn, apply opposite pedal, and then stabilize using pedals as required maintaining the heading. In strong winds weathercocking will cause the rate of turn to increase as the nose passes 180 degrees to the wind. Throughout the turn the cyclic is used to maintain position over the ground as you learned in previous hovering exercises. If there is a wind, the helicopter will tend to drift downwind; therefore you will have to displace the cyclic into the wind to counter this tendency during the turn. The stronger the wind the more cyclic is required.
Collective is used to maintain height in the turn. In strong winds, more frequent power’s changes will be required to maintain height.
In some piston engine helicopters the throttle may have to be adjusted to maintain the correct operating RPM as you manipulate the pedals and collective during the turn.
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直升机飞行训练手册 HELICOPTER FLIGHT TRAINING MANUAL(21)
