S jedno stranog foruma, c/p
I think people's yes/no answers depend largely on them ignoring these
two points. To clarify, imagine the treadmill runway but with a fixed
control tower at the start.
Scenario A - Lets assume that the plane tracks the treadmill's speed:
The treatmill starts moving at whichever ludicrously high speed you
care to mention and the plane's engines are running. For the plane to
remain stationary relative to the control tower, the engines would
only need to operate at a power to overcome the friction on the
free-spinning wheels - as previously quoted by egon_spangler, about
12% for a 747 with the wrong wheels on a concrete treadmill (a whole
new question, I feel?). In this instance, will the plane take off?
Answer: Absolutely not as there is no airspeed/lift (see everyone
elses comments for further explanation)
Scenario B - the treadmill tracks the planes speed: The "speed" of the
plane would be it's speed relative to the control tower. If the plane
accelerates to 100mph, the treadmill would accelerate to 100mph, and
the net effect would cause the wheels to spin at 200mph. However, the
plane would still be moving forward at 100mph. (For the plane to
remain stationary relative to the control tower, there would have to
be no speed, and so the treadmill would not move either.) Will the
plane take off?
Answer: Absolutely yes. Once it achieves the necessary speed relative
to the control tower, the airspeed would be sufficient to create the
lift. Granted the plane will have to overcome more friction on the
wheels than it would on a static runway as they are moving at twice
the speed, but the engines would easily overcome this.