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Old October 9th 07, 09:35 PM posted to sci.physics,rec.aviation.piloting,alt.usenet.kooks
Bertie the Bunyip[_19_]
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Default Airplane Pilot's As Physicists

Le Chaud Lapin wrote in
ups.com:

On Oct 9, 3:22 pm, Randy Poe wrote:
On Oct 9, 4:08 pm, Le Chaud Lapin wrote:

Hi All,


There is a long discussion ongoing in rec.aviation.piloting about

what
causes lift on a plane.


Heh. I know the argument. I think it's broken out here (sci.physics)
many times.

(a) It's the Bernoulli effect due to the shape of the
wing cross-section, the way we were all taught as kids.

(b) No, it's just the angle of attack.

I'm no expert, but I heard enough in similar arguments here
to convince me that the angle-of-attack people are right and
the shape of the wing has more to do with controlling
turbulence.

There are people in the pilot's group, who think that lift on a

wing
is analyzed as such:


1. There is air on outside of top of wing that is pushing down, but
reduced because of aerodynamics.
2. The *inside* of the wing contains air pushing up against the
underside of top of wing .


Er... that's a new one. OK, I haven't heard this argument
then.

3. Let us ignore that the same air inside the wing pushes down on

the
overside of bottom part of wing.
4. The difference in pressure against the underside of the top wing

on
the inside of wing and top of wing on outside, is what gives plane
lift.


You can consider that last just a definition of lift. You
won't get lift unless the upward forces are stronger than
then downward forces.

Note that they ignore the pressure inside the wing that pushes
downward on the wing.


A wing doesn't need to be hollow to fly.

I am trying to convince them that, if there is air on the inside of
the wing, it pushes against all sides of the inside of the wing,
including both top underside and bottom overside, and thereby
nullifying any effect it would have on the wing. Lift is caused by

a
difference in pressure between the underside of the bottom of the
wing, and the overside of the top of the wing.


Thanks Randy,

But before we talk about what causes lift on the plane, we should
clear up the basic physics 1st. Note that what I have described above
has nothing to do with airplanes really.

If you read carefully, the premise of what they are saying is that, if
you have, for example, a sealed jar with air in it, you are permitted
to consider the air on the _inside_ of the jar, pushing up on the lid
as contributing to a force to lift the jar off the ground, but you are
not allowed to consider the air on the _inside_ of the jar, pushing
down on the jar un the upper surface of the bottom of the jar.



Oh for ****'s sake.

You push on something it moves, right?

Everone already knows that, Stephen hawkings.


While you're trying to agitate in a physics froup why don;'t you ask
them how it's physically possible to get your head that far up your own
ass.

Bertie