Originally posted by: gsellis
Originally posted by: DrPizza
Hmmmm...
B. The idea of a conveyor moving the plane backwards wouldn't work. The plane is providing thrust against the air behind it. i.e. when you turn on the engines, the plane moves relative to the air; not necessarily the ground. If the ground were perfectly frictionless, the tires on the plane would not spin; yet the plane could still accelerate down the runway and take off. Thus, the conveyor moving in the opposite direction relative to the direction the plane is moving would have this effect: The planes wheels would spin faster; the conveyor realistically could *not* keep the plane stationary.
edit: changed the word "land"?? to "take off"
I found this on the AT-Wiki for ownage. Proof on the last page, but this is the first, correct answer. But, of course it is, because it is the Dr.
The net from the wheels and conveyor belt are almost 0 except for friction as they are free wheeling. Thrust moves it forward. This creates airflow across the wings. This generates lift. When lift > weight, flight. And some very warm bearings on the wheel hubs. Consider that a General Electric turbofan on Boeing 757 produces 50.000 lbs of thrust (each) and flows up to about 800mph, even with bad wheels, the bearings and rubber would lose.
And I know what you are thinking, planes weigh more than 100,000lbs. Thrust has to be equal to drag where the forward speed creates enough lift to be greater the weight. Thrust does not need to equal weight unless you want to go ballistic.
Yep, the wheels are just a distraction.