Someone posted link to image which is perfect description of
what is actually happening.

http://makeashorterlink.com/?B25A35DCC

I agree that this link does not accurately describe what is happening.
It is what I thought too until I thought about it some more (at the
prompting of this very newsgroup). The image shows less upwards force
on the higher wing. This much is true. What the image does not show is
the horziontal forces on the wing. The lower wing, being flat to the
ground, have no net horizontal forces on them. The higher wing however
does, since the wing's lift is not actually pointing in the upwards
direction, but is normal to (at right angles to) the wing's surface.
Since the wing is tilted, there is a horizontal component of lift at
work. Ignoring gravity for a moment, you can rotate the diagram any
which way, and the lift vectors will always be normal to the wing, and
will always have a net zero =torque= (and it's torque that would, by
this explanation, return the aircraft to level). Looking at it another
way, the higher wing has a horizontal component which will tend to
rotate the aircraft along the longitudinal axis, in the opposite
direction and with equal force as the "excess lift" attributed to the
lower (horizontal) wing.

So, this explanation is incorrect.

Jose
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