There's no question that its propulsion is independant of the tires, and that as far as that goes, it will fly...

The part I'm still considering is the tire speed...the conveyor matches the PLANE'S speed...but is working as a tread mill, so the belt is rolling under the tires at the PLANE'S speed...just like a tread mill is going under your feet at YOUR speed...

Isn't that the speed the tarmac goes under the plane as it rolls down the runway anyway?

My FIRST impulse was that it would be DOUBLE the speed...but, its a given in this scenario that it MATCHES the plane's speed....so it CAN'T be double....it has to be the same.



So lets say the plane accelerates to 180 mph air speed...the belt is going 180 mph ground speed towards it under the tires...

That's the same 180 mph the tires would be rolling along at w/o the tread mill.



IE: The tires are moving at normal speed , just like for any take off...but, the plane is going forward due to engine thrust...with the belt accelerating its tread mill speed towards the plane to MATCH the plane's actual speed.



Here's the kicker though...the tire is obviously moving forward with the plane's air speed...so the tire is travelling at say 180 mph forward - the conveyeor is also moving at 180 mph towards it...

...if the plane is standing still in the air, with the runway rushing beneath it at 180 mph...its easy to see that the tire has to be ROLLING at 180 mph...

...but, for the air speed to also be 180 mph...the plane will at SOME POINT actually reach the end of the runway and fly off...so it has to gain on the belt's length's static starting position....

So -

As the belt speed matches the plane's speed as a given...I'm back to the tires having to ROLL at double their actual air speed.