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Old 17th November 2004 | 10:19
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Genghis the Engineer
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You need lateral stability - dihedral being the most common way to achieve that.

There are two other ways however - one is to use pendular stability - in other words a CG reasonably well below the wing, the other is to use wing sweep.

Personally I'd go for a combination of a small dihedral value and a high wing (so giving at-least a little pendular stability). You probably also, to ensure post stall controllability, want to try incorporating a little washout - somewhere in the order of 2-4°. Sweep I'd not bother with, since that does become slightly difficult and you're unlikely to need the directional stability advantages if you put a reasonable fin on it.

Don't forget by the way that for a degree project, you really need to be able to justify what you're doing by reference to a good stability analysis. I'd suggest you get hold of a copy of Darrol Stinton's "design of the aeroplane" which should help a lot in that regard.

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