Quote Originally Posted by NSCredondo
Thats what Im saying. If the treadmill moved backwards and the plane moved forwards it would still slow down the plane and not let it take off due to not having efficient airflow over the wings.

Now:Hypothetically speaking if your car tops out at lets say 150MPH, and you put your car on a treadmill that went 150MPH in the opposite direction. If you topped out your car on the treadmill would the car be stationary or be moving 150MPH? I would think that it would be stationary.
The problem with your flawed analogy is that a car is propelled by it's wheels, where as a plane or jet is not. The speed of a treadmill is a moot point. The wheels (which are the only contact points on a plane or jet to the ground) are free spinning bearings. Keep in mind that a plane or jet derives it's speed relative to the ground, not the spot where it touches the ground.