Re: Wing section and angle of incidence

From:         k_ish <>
Organization: Netcom
Date:         Tue, 7 Apr 1998 03:57:16 GMT
References:   1 2
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Al Gerharter wrote:

> <snip great explanation>

> Yes the wing is set at an angle of
> incidence
> to the fuselage. The root of the wing has a much greater angle of incidence than
> does the tip. Called washout, it is the change in angle of incidence(or in flight,
> AoA)
> between the root and the tip. This loads most of the lift next to the root where
> it
> can be supported, and where the rest of the wing acts as a "fence" or winglet to
> minimize the vortices produced by producing lift.<snip>

Another reason for washout is to ensure the wing root section stalls before the tips.
This has several effects:

-  Maintains aileron control in a stall.
-  Creates a gradual, progressive stall instead of the entire wing stalling suddenly.
-  In swept-wing aircraft, the loss of lift at the root while the outboard section is
still making lift pitches the nose down, which assists in stall recovery.

Many light aircraft have no washout.  They often have "stall strips" (a piece of metal
running spanwise along the leading edge) to cause the inboard section of the wing to
stall first.

Ken Ishiguro