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Old 10-31-2006 | 04:06 PM
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Tall Paul
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From: Palmdale, CA
Default RE: What does washout means?

ORIGINAL: Richard L.


ORIGINAL: dick Hanson

You can't reshape a given area and increase lift- --you CAN make the wing more controllable at a given speed - but thats it.
Flaps do that too The lift does not increase (tho drag does) but the descent angle is more controllable.
One more question: If flaps do not increase lift by reshaping a given area, then why do my planes balloon way up when I deploy them?
It's the change in Cl with the flap. The Cl with flap is higher than the Cl without flap, but it occurs at a lower angle of attack.
If the alpha isn't changed, the plane falls out of the sky.
Example... Cl near stall, about 8 degrees alpha, without flap. A
60 degree flap the -same- Cl (the lift hasn't changed) is -5 degrees. B.
Lowering the nose puts the wing outboard of the flap at -5 degrees C, well below stall, and the same effect as a LOT of washout.
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