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. Landing sites on the bottoms of valleys often have difficult access, and frequently leave no escape route once an approach has started. In this case, it's important to have safe power reserves before committing yourself. In any case, placing the aircraft downwind near to ground should be avoided, but if you have to, go low and slow when approaching downwind with a last minute turn into wind. In snow, try landing with the sun behind you, as the aircraft shadow will give you a useful guide to the ground slope and surface and provide a focus for a sight picture approach. Some people use the landing light. For takeoff, try not to hover too much. A jump takeoff is useful if little power is available, where you get light on the skids, proceed to the edge with full RPM and tip yourself over the edge. Good fun, but you should be able to hover at least for a moment, just in case your C of G is out. In a confined area, for a JetRanger, at least, you need about 15% torque in hand to do a proper vertical takeoff, so you’re probably OK if you’re hovering at about 80%. Near the end of a cliff (or the deck of a ship), try and keep the tips of the rotors as far as possible over the edge, to avoid a vortex formed by wind movement over the edge (a backlash) mixing with your downwash, which will affect the airflow so much that you will need more power in a low hover. It’s a similar effect to the recirculation found when hovering near a building, where the accelerated air going through the disc actually pulls your machine towards the wall, and more power is used to stop it. Log Pads and Platforms
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