Actually, James, as I understand it, it's not that it takes the top molecule longer, but that it is forced to move faster; and faster-moving air is lower in pressure than slower-moving air (all else being equal). It's the venturi effect.

However, there's another factor in play, which is often downplayed: the angle of attack. A wing gets lift by displacing air molecules downward... the same effect as when you stick your hand out the window of a moving car and slant the palm upward. Many types of planes get a large fraction of their lift from this mechanism. Some wings are actually symmetrical (no difference in the top and bottom contour).

But I agree with the original nit: the BA was a bit too concise in his description.

(Corrected grammar)

<font size=-1>[ This Message was edited by: Donnie B. on 2002-04-19 19:21 ]</font>