but it's the proper use of newton's laws that proves that the plane actually moves in THIS case. i'm not saying you're wrong about bernoulli's principles. just saying that the bernoulli's principles weren't in question in this case. almost everyone in the thread applied them correctly. what most people were doing was actually applying newton's laws wrongly here. that's why i only mentioned those.
Well, where I was going with that was more along the lines of why the plane moves forward to begin with. It's a combination of Newton and Bernoulii. The rotar spinning creates an air pressure difference (it doesn't push air over the wings to make lift) in front of the air plane, which causes the plane to be pushed/pulled forward by that difference. That's Bernoulli. There is a force pushing against the air, so there has to be an equal and opposite reaction against that. That reaction is the plane moving. That's Newton. Hence the combination of laws.
Newton's laws take care of the conveyor; the negative motion of the conveyor is transfered to rotational motion through the wheels since, so all motion is conserved there. Since the wheels spin independently of the plane, that component is taken care of.
But if the plane stands still, that means the force the propeller creates has no opposite force acting on it, so there is no conservation of forces...which would violate the laws of physics.
Like I said, I could go on for a long while about why this worked/works, but you already get the idea so I'll shut up.