I'm with bruno on this one. The plane takes off.

Unideal plane, unideal conveyor belt - the belts going to fall to pieces before it has a chance of increasing the rolling resistance enough to slow the plane down. Ideal plane, ideal conveyor belt, the belt has no effect, as the plane obviously has frictionless wheels. The only way the plane doesn't take off is if you've got an unideal plane, and an ideal conveyor belt, which just isn't fair.

Matthew