This is interesting problem. What little I know of how a plane flies, if I recall correctly, is that air must go faster over the top of the wing, causing the air pressure over the wing to become less than the air pressure below the wing. This causes the lift to allow the plane to rise.

Now I picture this problem as follows; if the plane is going forward at the same rate the conveyer belt is pushing it backwards, so to say, it seems to me the plane would always be in the same spot, so there will be no airflow and the plane will not rise.

My analogy is my using the treadmill at the gym (a treadmill works on the same principle as a conveyer belt. If I set the machine to 4mph, and move my legs at the same pace, I will stay at the same spot on the the treadmill. If my legs tire and I slow down, I will be pushed back by the belt, and conversely if I walk faster than the 4mph, I will move forward.

Where have I gone wrong (as I am not an airplane, and I never get a lift, only tired) in my analogy?