Sisyphus Posted December 13, 2004 Report Share Posted December 13, 2004 Advice The situation frequently arises in which one wants to approach and land on a ridge across which the wind is blowing perpendicularly. To approach the intended point of landing directly into the wind results in the last several hundred metres of the approach facing the ridge. If it is necessary to abort the approach, a likely cause of which would be turbulence generated by the ridge, a turn of at least ninety degrees is required and if a descent is also begun, the machine may encounter downdraft. The solution is to approach the intended point of landing perpendicular to the wind with the wind on the left. In machines with American rotor rotation, this has the advantage of assisting left pedal. The machine can flown directly over and along the ridge or slightly in front of it, maintaining the flight path in smooth air and permitting the pilot to roll to the left only a few degrees and easily clear terrain if such action is required. Try to reduce airspeed to slightly above translation several hundred metres back. Make the approach as flat as possible and apply power smoothly and well in advance. Avoid rapid, last second applications of power. As the machine slows do not try to keep the nose pointing straight ahead but let it weathercock into the wind as airspeed is reduced. This will probably result in the helicopter travelling sideways across the ground for the last part of the approach but if the breeze is sufficient, little or even no left pedal need be used. The other great advantage of this is that the landing spot will be plainly visible out the window on pilot's door through which the visibility is much better than that forward. The same method can be used on European machines except that the breeze is on the wrong side of the machine to assist right pedal. To make the approach with the wind on the right results in the landing spot being on the side of the machine opposite the pilot. This is very awkward as the pilot cannot see where she is going. If at any time the pilot experiences discomfort with the progress of the approach, she can escape by rolling only a few degrees to the left and be directly into wind with several hundred or even several thousand metres of airspace beneath her. The essential thing is that the nose of the aircraft be kept pointing directly into the wind at all times. Caution must be used in the presence of zephyrs. Light winds are often variable in direction. It takes very, very, very, very small change in wind direction to run out of pedal when landing at higher elevations on a warm day with a heavily loaded machine. A wise pilot also uses the out of ground effect charts for mountain operations for the first approach to a ridge or pinnacle. Ground effect will not be acquired at a majority of mountain landing sites. After a landing spot has been used once and the pilot is familiar with the wind a terrain, it may be advisable to increase gross weight . It is essential to know precisely the gross weight of the helicopter. The out of ground effect hovering charts should be kept at hand in the cokpit so the pilot can consult them if necessary. Air density can change rather drastically over surprisingly short vertical and horizontal distances in the mountains. A wise pilot will also ensure that her site of intended landing is such that a level landing can promptly be made. A thorough reconnaissance will reveal the suitability of the landing site in this regard. It is folly to fiddle around to find a level spot on which to place the skids once the landing area has been attained. This advice is rudimentary. The cited principles will be amongst the first discussed in any course of instruction on mountain flying. Quote Link to comment Share on other sites More sharing options...
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