AviationBanter - View Single Post

alexy · February 4th 06, 08:12 AM posted to rec.aviation.student,rec.aviation.piloting

wrote:

If you restate the problem as follows the aircraft will obviously NOT
fly.

The aircraft is on a conveyor belt.

The conveyor is programmed to move in such a way as to maintain the
aircraft at an airspeed of zero as measured at the pitot.

Absolutely, if you CHANGED the problem, and restated it as above, then
it wouldn't fly. Another way to state your entirely different problem
is to say that the conveyor is set up to always move at a speed that
maintains the wheel speed of the plane as the same as the conveyor
speed.

Or to parallel the original problem, "a conveyer belt that moves in
the opposite direction to the way the plane is pointed, at exactly the
speed that the airplane' wheels are moving, so that the plane is not
moving"

This will require a VERY fast conveyor, since once power is applied
and the brakes are released, it will have to move fast enough that the
rolling friction of the tires and bearing friction in the wheels
offset any thrust provided by the plane's propulsion system. Sounds
about as possible as any other conveyor belt runway!

cjcampbell wrote:
Saw this question on "The Straight Dope" and I thought it was amusing.

http://www.straightdope.com/columns/060203.html

The question goes like this:

"An airplane on a runway sits on a conveyer belt that moves in the
opposite direction at exactly the speed that the airplane is moving
forward. Does the airplane take off?" (Assuming the tires hold out, of
course.)

Cecil Adams (world's smartest human being) says that it will take off
normally.

--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.