Quote:
Originally Posted by nuggetsyl
I will have to disagree. Engines at full power means nothing. If you retract the landing gear you will crash the plane because your air speed is 0. Many people are confusing ground speed with air speed. If air is not going over the wings you can not lift a plane off the ground plain and simple.
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I normally don't post in these kind of threads, yet i feel the need to in this one.
There is an airspeed/ground speed issue here.
Think about the problem in terms of the horizontal forces -- You have the thrust of the aircraft pushing the body of the plane forwards, you have the force of the treadmill being pushed opposite the engine thrust on the wheels.
F=M*A tells us that if these two forces do not equal each other, the plane will accelerate with the direction of the greater force.
As for the force being applied by the treadmill, onto the wheels -- If you think about where that force is being applied, and in what direction, you'll see that it's acting tangent to the wheel, so all (well nearly all) of that force goes into rotational motion on the wheel. I say nearly all because of any wheel bearing friction. So that force goes to almost zero.
Since there is still a force being applied to the aircraft frame by the propeller or jet engine, the plane will accelerate (f=ma)
When the plane reaches normal takeoff speed, the wheels will be spinning at twice normal takeoff speed (due to the treadmill below), but because they are free-spinning and not powered wheels, there is almost no difference between this and a normal takeoff.
my $.02