Bob Gardner wrote:
If the goal is to give the student an easy-to-grasp concept, ground
cushion is just fine *as an introduction to the discussion.* If the goal
is to use technically correct phraseology at all times whether it
penetrates the student's skull or not, then reduction in induced drag
and downwash angle do the trick.

Bob Gardner

"Cubdriver" usenet AT danford DOT net wrote in message
...
On Mon, 25 Feb 2008 09:46:30 -0800, "gatt"
wrote:

Rather, Collins talks briefly about "ground cushion" and how air
"piles up"
beneath the wings.

Do people still teach this?

All I can say is, if you rely on that ground cushion to soften the
impact, you will be sorely disappointed.

Blue skies! -- Dan Ford

Claire Chennault and His American Volunteers, 1941-1942
new from HarperCollins www.FlyingTigersBook.com

I agree. I've used the "ground cushion" analogy many times when opening
up the issue of ground effect with primary students. Using chalk and a
blackboard to demonstrate how, and where the cushion forms under the
airplane is one of the ways to take this first step. Once the student
knows ground effect actually exists and what it does, THEN is the time
to begin to explain the "devil in the details" :-)

--
Dudley Henriques