On Oct 9, 1:30 pm, Le Chaud Lapin wrote:

If air inside the wing pushes upward on the underside of the top of
the wing, it also pushes downward on the overside of the bottom of the
wing, thus nullifying any effect of the air inside the wing.


OK, I'm going to try once more. Let's say the wing is standing
still. It is surrounded by normal atmospheric pressure. It has
normal atmospheric pressure inside it. No net effect, right? Now
lets say you could cause an area of low pressure over the top surface
of the wing. You have normal pressure inside the wing pushing down on
the inside bottom of the wing. But you have normal air pressure below
that surface pushing up. These cancel each other, and you have no net
effect from the bottom surface of the wing. But the bottom surface is
not pulling down compared to the top surface. It has no net effect
because the pressure on both the inside and the outside of the bottom
surface of the wing is the same.

But what about the top surface of the wing? You have normal
atmospheric pressure inside the wing pushing up against the bottom of
the top surface of the wing. But outside the wing above that surface
you have lower pressure. That is a net difference, and that would
cause lift. It wouldn't be countered by the pressure against the
inside bottom of the wing because that is countered by the pressure
outside the bottom of the wing.

It's the same situation you have in flight, except then you have the
addition of higher pressure under the bottom of the wing. Both the
high pressure under the wing and the low pressure above the wing
contribute to lift.

Phil