Rinky, you're a dumbass. You state: How can a treadmill cancel out air flow? All the treadmill is doing is spinning the wheels. The treadmill could spin the wheels on the plane up to a million rpm and it wouldn't make any difference.

1. put your car on a treadmill.
2. shift it into neutral.
3. turn on the treadmill.
4. The car's wheels will start spinning, but the car itself will realize ZERO forward motion.
5. Put the car in gear and mash on the gas.
6. the engine of the car turns the wheels which are fighting the treadmill. The car still doesn't go anywhere.

That's where YOUR brain stops. Lets do the same experiment with a jet engine strapped to the roof of your car.

1. put your car on a treadmill.
2. shift it into neutral.
3. turn on the treadmill.
4. The car's wheels will start spinning, but the car itself will realize ZERO forward motion.
5. Light the jet engine.
6. The jet engine doesn't turn the wheels like the car's engine would, it thrusts back into the air. The car will rocket forward because for every action, there is an equal and opposite reaction (Newton).