Aye mrford, agreed that the wheel bearing force is minimal. But all the treadmill has to do is cause enough force in the opposite direction to stop the plan from reaching takeoff speed. If it isn't moving fast enough it cant take off.

So if the treadmill is moving backwards fast enough (and yes I agree it would have to be a stupid fast speed for that to happen, like 10,000 km/h) it would slow the plane down enough so between air friction, and the treadmill wheel bearing friction it is possible to stop a plane from taking off.

Also depends on the type of planes, some planes, especially smaller ones, need 90% of their power right away to begin taking off successfully, I can easily see a Cessna not being able to take off as wheel friction plays a far bigger part. Where as a 747 I agree, since it has so much overkill powerwise, it might be able to take off anyway, but I disagree that if the treadmill was moving 1bil km/h it would be able to. If for only the reason the plane wouldn't to take off in a straight line, since it is likely the tires will melt, or at least have no friction in relation to the treadmill.