Wing washout ??
07-01-2007, 08:53 PM
#2
Senior Member
RE: Wing washout ??
Its when the wing is twisted so that the tip is at a lower angle of attack then the root, usually about 2 degrees. This allows the root to stall first there by allowing a gentler stall.
07-01-2007, 08:54 PM
#3
RE: Wing washout ??
From the RCU glossary:
This term is used to describe a designed warp in the wing of an airplane. The warp makes the angle of attack more steep at the wing tips than at the root of the wing. This helps prevent tip stalls.
Actually, P-40 driver is correct and it should read "lower angle of attack". The glossary is incorrect.
Basically the wing chordline at the wing root has a higher angle than the tip ribs. This causes the wing centersection to stall before the tips and reduces "tip stall" tendencies. As you flair for landing the center stalls and the tips keep flying longer. EDITED TO CORRECT
This term is used to describe a designed warp in the wing of an airplane. The warp makes the angle of attack more steep at the wing tips than at the root of the wing. This helps prevent tip stalls.
Actually, P-40 driver is correct and it should read "lower angle of attack". The glossary is incorrect.
Basically the wing chordline at the wing root has a higher angle than the tip ribs. This causes the wing centersection to stall before the tips and reduces "tip stall" tendencies. As you flair for landing the center stalls and the tips keep flying longer. EDITED TO CORRECT
07-07-2007, 08:59 AM
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RE: Wing washout ??
More specificaly it allows for aileron use through the stall thus allowing for contollability of the roll axis. If however the wing slows to a point that the entire wing does infact develop a stall no amount of wash out will prevent a tip stall. It is all about speed. Stay away from Vns
07-07-2007, 04:11 PM
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RE: Wing washout ??
It is all about angle of attack. Speed has nothing to do with it. Stay off the elevator...
Rectangular wings stall at the root first anyway and don't need washout for that. It gives a more elliptical ( more efficient ) lift distribution while cruising. Since we don't "cruise" much in the R/C world, the other benefit might be a slightly better glide ratio.
Rectangular wings stall at the root first anyway and don't need washout for that. It gives a more elliptical ( more efficient ) lift distribution while cruising. Since we don't "cruise" much in the R/C world, the other benefit might be a slightly better glide ratio.
07-07-2007, 07:53 PM
#7
RE: Wing washout ??
Looks like it's all about getting the story straight.
Washout is a term that refers to the twisting of the outboard portion of a wing (trailing edge up) to reduce the angle of attack of the outboard wing section relative to the inboard portion. Doing this assures that the outboard section will not stall before the inboard section. At stall speed, the center will stall first and the tips will follow. This prevents the onset of uncontrolled roll during slow speed flight, especially during the landing approach and touch down where you don’t have altitude to correct the condition. The roll will occur when one wing tip stalls before the other or before the rest of the wing.
Washout is a term that refers to the twisting of the outboard portion of a wing (trailing edge up) to reduce the angle of attack of the outboard wing section relative to the inboard portion. Doing this assures that the outboard section will not stall before the inboard section. At stall speed, the center will stall first and the tips will follow. This prevents the onset of uncontrolled roll during slow speed flight, especially during the landing approach and touch down where you don’t have altitude to correct the condition. The roll will occur when one wing tip stalls before the other or before the rest of the wing.
07-07-2007, 09:37 PM
#9
RE: Wing washout ??
ORIGINAL: CGRetired
I thought that was wha he (Bruce) said.
I thought that was wha he (Bruce) said.
Just remember that AOA is what is most important. A wing can stall at any airspeed depending upon the AOA. Ever been in a plane pointed straight down at 100+ mph with the stall horn on? I have, not nice. Advice: be in a Pitts like I was.
