Quote:
Originally posted by BlueSky:
See, this is what I'm saying. Your argument rides on a tailwind of fixed velocity. In the scenario, the conveyor moves faster and faster as engine thrust is increased, so the speed relative to the surrounding air remains zero.
Here's the thing, though. The tailwind does not take the place of the conveyor. It merely serves to illustrate that the wheels can meet double the friction (just like the conveyor provides) and still take off.

If the tailwind were ever-increasing to match the groundspeed of the plane, then of course the plane would not fly.