How do you suppose that the belt and the atmosphere are moving at the same speed?

That is, you're saying that relative to the plane, both the belt and air are stationary. But as viewed from a remote place, they could all be moving 200MPH. How do you expect that the air is moving 200MPH? And, if it is, where is the transistion between the 200MPH near the airplane and the near-zero MPH near the remote observer?