depends of the plane, some weird freaky looking plane could do it like that Actually i understand it and it depends on how you interperate the riddle, if you assume the plane is keep stationary then there is NO chance the plane would take off, but for the convoyer belt to do this, The wheels would have to be attached to the engine, but they are not! that was 10 years ago - brain fade!! haha i was failing a - level does that count,so i gave up!!!