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Old October 7th 07, 06:58 PM posted to rec.aviation.piloting
Le Chaud Lapin
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Posts: 291
Default Backwash Causes Lift?

On Oct 7, 11:54 am, flightoffancy wrote:
JC, you're confusing yourself.

Instead of focusing on "fixed" wing, think for a moment about helicopter
blades and propellers. These are airfoils not fundamentally different
than one attached to the side of an aircraft.


Agree.

Anyone who has ever seen video of a helicopter hovering or has been near
a helicopter hovering knows that air is being pushed down by the blades
with massive force and that is the equal and opposite force exerted by
the mass of air on the bottom of the blades that keeps the helicopter
from falling out of the sky.


More agreement.

A fixed wing aircraft is only different in that it pushes air under it
by moving forward, rather than in a circle.


Even more agreement.

The bottom line is simple: an airplane can only stay aloft by pushing
air down.


Still even more.

Yes, the angle of attack gives the greater impulse to knock the air
downward. But a curved upper surface gives even more downard force to
the air.


Still even more.

Nit-picking Jeppensen's watered down description, which was not authored
for aeronautical engineers (which I note you are NOT), will not advance
your piloting skills in any significant way.


There is one small problem with your exposition:

You are referring to the bottom of the wing.

Jeppesen is talking about the top of the wing.

-Le Chaud Lapin-