I asked this to a buddy whom is a retired AF Maj. Here is his answer:
Despite what Mythbusters says, this is not possible. If the treadmill is traveling at the same speed as the plane, there is no airflow over the wings. Without airflow, there is no lift.
Now, with that said, here is how they get around the issue. By using a propeller to generate the thrust needed to “move” the airplane at the same speed as the treadmill, the propeller is pushing air over the wings, causing some lift. In very light aircraft, you might even create enough lift to get the aircraft airborne, but you have changed the original equation. If you use a jet engine which bypasses the wings, the answer is a little clearer. Better yet, use a glider that matches the speed of the treadmill by having a support that keeps the glider from moving backwards. Unless you can get the treadmill going fast enough to generate airflow over the wings, it’s not gonna happen!
If you stick to the physics involved in the original setup, it is not possible. Mythbusters “disproved” the myth, but in both cases (model and full size) the aircraft was moving forward when it got airborne.
|