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时间:2011-04-22 10:17来源:蓝天飞行翻译 作者:航空
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When hover-taxiing your helicopter, maintain a speed that is about the same as a normal walking pace. Any faster and you may begin to encounter effective translational lift; control of the height will then be somewhat difficult as the helicopter will want to climb. Should this occur when taxiing sideways or to the rear, it is possible to exceed the manufacturers airspeed limitations for those directions. Fast taxiing to the side or rear will require judicious use of pedals to counter any weathercocking tendency. Remember that flapback can occur in any direction, not just in forward flight, and the pilot will have to overcome it in the usual manner when hovering to the rear or to the side.
SIDEWAYS FLIGHT
To commence sideways flight from the hover, proceed as follows (Fig 16-1):
1. pick two reference points, one to the front the other to the side to help you maintain the correct ground track. Perform a 90 degree clearing turn to look out, checking the area for any obstacles or other traffic;
2. apply a small amount of cyclic in the desired direction to begin the helicopter moving;
3. maintain the hover height with collective, preventing sink as the disc tilts;
 

Figure 16-1: Sideways Flight 
 4. apply pedals as necessary to maintain heading and prevent yaw or weathercocking;
5. adjust the cyclic as required to overcome flapback and to keep the helicopter moving at a smooth, constant rate; and
6. alternate between looking forward to ensure the helicopter remains on the original heading and in the direction of movement for any obstructions.
To bring the helicopter back to a hover:
1. smoothly apply cyclic, opposite to the direction of movement, to select the hover attitude;
2. maintain a constant height with collective and the original heading with the pedals, pause; and
3. as the sideways motion ceases, adjust the cyclic to establish a steady hover and maintain the original heading.
REARWARD FLIGHT
Before commencing rearward flight, do a clearing turn of 90° or 180° to ensure that there are no obstacles in the proposed flight path, and to identify the point at which you will cease your rearward flight. Once you are satisfied that the area is clear, return to your original heading and after picking you reference points:
1. increase your hover height by 1 to 2 feet, to compensate for the fact that while moving to the rear, the helicopter’s attitude will be tail low. This extra height will ensure adequate tail rotor clearance;
2. apply aft cyclic to begin rearward movement. Anticipate flapback with a further cyclic application to achieve a smooth constant rate of movement;
3. maintain height with collective and direction with pedals; do not attempt to look to the rear as this will only cause you to lose sense of the desired direction of flight; scan to the front and to the side to ensure that direction is correctly maintained.
To return the helicopter to the hover:
1. smoothly apply forward cyclic to select the hover attitude, pause;
2. as the helicopter comes to a stop, adjust the cyclic to hold the helicopter in a steady hover;
3. hold the heading throughout with pedals; and
4. once all motion has ceased, lower the collective slightly to re-establish normal hover height.
In the operational environment, there is seldom the need for lengthy rearwards hovering-taxi and if for some reason you must do so, it is good airmanship to periodically stop and do another clearing turn to check that the area is clear of obstructions. Be aware that in both turbine and reciprocating engine helicopters, exhaust fumes can enter the cockpit under certain wind conditions while hovering to the rear.

 
Figure 16-2: Turn around the tail 
TURNS AROUND THE TAIL 
This is a useful manoeuvre from an operational standpoint (Fig 16-2) and you will find that it is often used when required to re-position the helicopter within a confined area. The techniques are similar to those, which you employed in sideways hovering (See figure 16-1).
 
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