747 on a treadmill conundrum..

[Jenny A]

All that matters in this conundrum is the speed of the plane's wing relative to the air.

That's it.

As long as the speed of the air over the wing is below the level to achieve the necessary lift, plane won't become airborne, no matter how fast those wheels are a-spinnin'.

This is kinda basic.

Yep. That's why I like my kite analogy. If there's wind, the kite flies. If there isn't you can get it in the air by running across the ground because that moves the kite relative to the air. But, if there's no wind and you run on a tread mill the kite will still just lay there. Set up a big enough fan and you can lift either the plane or the kite.