A better way to pose the airplane question would be " what would
happen if the airplane is landing on a treadmill that is moving in the
opposite direction and speed?"

How about dispensing with the treadmill entirely. What would happen if
the airplane were on a frictionless surface? The wheels couldn't push
on anything, so how would the airplane take off?

Jose
--
"There are 3 secrets to the perfect landing. Unfortunately, nobody knows
what they are." - (mike).
for Email, make the obvious change in the address.