In article ,
(Teacherjh) wrote:



is it really the prop that picks the stones up? Anybody studied the physics
involved?

Watch an airplane during a runup with standing water on the surface.
Directly under the prop you'll see a little "mini tornado" of water
being picked up from the surface. If you happen to watch someone
foolish enough to do a runup over dirt/gravel you'll see the same
thing...but it will be dirt/dust/rocks in the tornado instead of water.

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html