I understand the concept of the plane being able to move forward but I read the problem a lot like RB26powered did.
Planes can takeoff standing still with no motors on if the headwind is strong enough, all that matters is the relative airspeed. If a plane is on a treadmill, it will be moving but not covering any displacement and it's relative groundspeed (and thus airspeed unless there is headwind or tailwind) will be 0.
So say you've got a plane that needs 80mph airspeed in order to takeoff: if you accelerate the plane to 40mph and air and have 40 mph headwind your relative airspeed is 80 and the plane can takeoff. I dont see that happening on a conveyer with no wind, sure it will roll and accelerate but it wont take off unless it's a very long conveyer inside of a nicely sized wind tunnel.
