[rusaccord]

It took me a little bit to look at it, but I think I'm starting to see what's going on. The people who say that it won't take off are the ones who believe that the plane won't move forward. I agree with this, if the plane didn't move forward, then it wouldn't take off.

However, we're facing confusion in what produces the forward motion. Let's say you have a car standing on that treadmill runway with all of the same speed-matching conditions. The car won't move anywhere since whatever speed the engine spins the wheels at, the runway moves backwards. That means if you've got a wheel circumference of one meter (just to make things simple, I know it's not right), then for every rotation of the wheel, the runway will move back by one meter. The car won't go anywhere because the forward motion is provided by the wheels rolling forward, almost, crudely put, pushing off of the ground.

The airplane turbine, in the same crude way, is pushing off of the air. That's where the rolling chair and rope analogy comes from, I think. The rope is the air, and the air doesn't move. So, when the plane turns up its turbines, they push off of the stationary air. Then, for every revolution of the plane's wheel (let's say the same meter) the treadmill moves back one meter. Except what happens is since there's no driving force being applied on the plane wheels - they're not connected to an engine - they simply spin twice as fast and the plane moves forward. As someone said above, they act like bearings. Thus, since the plane is pushing against the air and not against the ground (like a car would), the plane moves forward and does take off. The thrust of the turbines moves the plane forward, from where Bernoulli takes over. However, you still need a full-length runway for this plane.