in a perfect world, i think the people who say the plane will fly are correct. the conveyor is basically adding a retarding force on the forward motion of the plane. Its like trying to take off against more resistance. say... using a plane just lying on its belly. lots of friction, but i suppose it could get going fast enough to take off. however, practically speaking, the engines on a real jet could doubtfully produce enough thrust to counteract the backwards pull of the conveyor AND still get the plane up to speed goin' forward.

i win. h: