You have the same mind block everyone has. Everyone thinks that the forward movement of the plane has something to do with the ground. It doesn't. Thrust of the plane comes from the prop or jet or whatever it has pushing against the air. Pretend for a minute that the plane didn't have wheels and it hovered like the hover board in the movie back to the future. There isn't any friction with the ground, right? So the treadmill wouldn't stop the plane from taking off, right? Well the wheels on a plane do nothing but minimize the friction with the ground unless the brakes are applied. If the thrust of the plane came from the wheels then no, the plane would not take off.