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Old 12th December 2005 | 16:34
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slowrotor
 
Joined: Jul 2003
Posts: 440
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From: Port Townsend,WA. USA
parachute

Dave
"rotor provides same lifting force that a parachute of the same diameter would provide" That is correct. But the helicopter disc loading is much heavier than a normal parachute and the descent is very high in a helicopter.

Indeed, the parachute descent may be better for sport helicopters and VTOL because the rate is slower. Also no pilot reaction within "1.1seconds" would be needed, a huge difference. And a parachute doesn't need 200ft of altitude to spin up in rpm.

A wing can be a fixed parachute. The low aspect ratio disc shaped ARUP, built in the 1930's I think, had the capability for "parachute landings" at a 40 degree glide slope.
For slow sport aircraft, the lift/drag of a large wing may replace autorotation.
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