时间:2011-04-05 11:32来源:蓝天飞行翻译 作者:航空 点击:次
To view this page ensure that Adobe Flash Player version 9.0.124 or greater is installed. TECHNIQUE Before attempting a maximum performance takeoff, bring the helicopter to a hover, and determine the excess power available by noting the difference between the power available and that required to hover. You should also perform a balance and flight control check and note the position of the cyclic. Then position the helicopter into the wind and return the helicopter to the surface. Normally, this maneuver is initiated from the surface. After checking the area for obstacles and other aircraft, select reference points along the takeoff path to maintain ground track. You should also consider alternate routes in case you are not able to complete the maneuver. [Figure 10-1] Begin the takeoff by getting the helicopter light on the skids (position 1). Pause and neutralize all aircraft movement. Slowly increase the collective and position the cyclic so as to break ground in a 40 knot attitude. This is approximately the same attitude as when the helicopter is light on the skids. Continue to slowly increase the collective until the maximum power available is reached. This large collective movement requires a substantial increase in pedal pressure to maintain heading (position 2). Use the cyclic, as necessary, to control movement toward the desired flight path and, therefore, climb angle during the maneuver (position 3). Maintain rotor r.p.m. at its maximum, and do not allow it to decrease since you would probably have to lower the collective to regain it. Maintain these inputs until the helicopter clears the obstacle, or until reaching 50 feet for demonstration purposes (position 4). Then, establish a normal climb attitude and reduce power (position 5). As in any maximum performance maneuver, the techniques you use affect the actual results. Smooth, coordinated inputs coupled with precise control allow the helicopter to attain its maximum performance. COMMON ERRORS 1 Failure to consider performance data, including height/velocity diagram. 2 Nose too low initially, causing horizontal flight rather than more vertical flight. 3 Failure to maintain maximum permissible r.p.m. 4 Abrupt control movements. 5 Failure to resume normal climb power and airspeed after clearing the obstacle. RUNNING/ROLLING TAKEOFF |