[QUOTE=X4DLuvOfSpeedX,Feb 13 2008, 08:54 AM] I agree that we need more responses like that.

 

The LSD in my spinal column is causing my brain to sieze over this thread....

 

Drink some vodka to flush your system while running on a treadmill and you will be fine.

 

Yes.

 

[QUOTE=duboseq,Feb 13 2008, 09:20 AM]Valid argument. Now I have a question because some people think the treadmill

 

Okay, it sounds like what you're saying is that a plane's engines can be feathered so low that a plane on a backwards moving treadmill can be held stationary. That is true. There's enough rolling resistance in a plane's wheels that some small force will want to push it backwards, and the engine can counter that with a tiny little bit of thrust.

I hope you realize though, that does NOT mean that the treadmill has any ability WHATSOEVER to prevent a plane from taking off, because the amount of rolling resistance is the same whether the treadmill is moving at 10mph or 10,000. Meaning, if the plane can overcome the resistance of a stationary runway, it can overcome the resistance of a runway moving backwards at any speed.

In our above example of a stationary plane on a moving treadmill, if you increase the speed of the treadmill from 10mph to 500mph, the plane will continue to remain stationary without any change to the engines.

 

[QUOTE=X4DLuvOfSpeedX,Feb 13 2008, 06:56 AM]Yes.

 

Let's get an imaginary scenario going. This one will be more clear, so there's no confusion as to what's happening.

1. Put a plane on a (long) treadmill.
2. Get the plane going 10 mph (under its on power)
3. Turn on the treadmill and set its speed to 10 mph in the opposite direction.

Q: What will happen.


I think the plane will continue to move at 10 mph and this treadmill's speed will not affect the plane's forward motion.

Your posts lead us to believe that you think the treadmill will cancel the plane's forward movement.

 

Ok here are some issues. I've done this just last night:


I put a tennis ball on my parents perfectly level treadmill and set the speed @ 1mph. You know what happened to the ball? It rolled off of the treadmill.

When I increased the speed 6mph, the same thing happened. that is why this is a bad example to begin with.

A heavy airplaine sitting on a treadmill while completly turned off would actually move backwards as the tennis ball did.

Now lets look at the same airplane. In a real world situation one would assume the same thing would happen as the tennis ball. Now lets say that the plane with proper thrust can maintain(sp) a speed that matches the treadmill to where it is in perfect relation to allow it to stay stationary on the treadmill.

Obviously the plane will not move anywhere unless it provided enough fwd motion (by way of thrust) to allow it to generate enough lift to get airborne.

If this is done, then yes the plane CAN take off of a tread mill.

Now if the treadmill is 10,000mph as you pointed out then I doubt the plane can generate enough fwd speed to provide lift.

 

Oh no...

If the plane is providing forward motion, then it is going somewhere...and a treadmill cannot prevent this forward motion.