时间:2011-04-05 11:37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. Turns will have a similar effect, but the results will be worse if pedals are used. Steep turns are good ways of losing height if you find yourself overshooting—if you are seated on the right, turn right first, then go left, so you have the best possible view through the windscreen, and you don't get the instrument bulkhead in the way on finals. If you are on the left, go the other way. However, some pilots alternately overshoot and undershoot the area they want to land in, rather than doing S-turns. What you do is bracket the spot with smaller and smaller movements until you hit (get used to what your machine does in straight-in autos). Each helicopter will have an optimum rate of descent for the longest range, but most light helicopters can stretch their glide at 10-20 mph faster than best lift/drag speed and maintaining the lower main rotor RPM limit. Best endurance speed will give the best lift in autorotation (i.e. minimum sink). Where winds or density altitudes are high, expect to increase speed a little, but decrease it when winds are calm or density altitudes are low, or you need a little time to choose a landing area or be a little more precise (see below). If you deliberately decrease the RPM to increase range (and possibly lessen the rate of descent), don't forget to build it up again for landing. A typical helicopter has a power curve looking like this: If you are aiming for a particular spot, you will have a better chance of hitting it if you keep your speed below the best speed mentioned above (60), as anything faster will cause you to float, and force you to anticipate the glide more (that is, the aiming point is different from the landing spot, and the faster you go, the more they will be different. If you only have one clearing, you will have a better chance of getting there and flaring very close to it if you keep your speed tight). If you are on the backside of the curve, remember to get your full speed up by 100 feet, or the flare will be just a change in attitude and fail to do its proper job of slowing you down (see below). . .
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