Mythbusters, Plane on a treadmill..

[Rekks Inbound]

And thereby lies the problem; it is not possible to build said treadmill, because the movement of the aircraft is not predicated upon friction with the ground, but rather a force against the air through which it moves.


Think of it this way: assume Vr is 100kts, so for good measure, we will run theadmill at 200kts. Now, if we reach out and grab the prop (with the engine not running, of course), could we then pull the aircraft forward? The answer is yes, because we are pulling the aircraft independent of the treadmill. Crank it up to 300kts, it doesn't matter, for the above reason.

Peace.

Rekks

 

[Papps]

I'm still willing to bet anything that the plane hits 85 and travels back to 1955.

 

[ImbracableCrunk]

And thereby lies the problem; it is not possible to build said treadmill, because the movement of the aircraft is not predicated upon friction with the ground, but rather a force against the air through which it moves.

Let's say you had a giant treadmill with an airplane on it.

As you add power and begin to move for the takoff roll, the treadmill speeds up and keeps the plane in the same relative position. As the plane goes faster, the treadmill speeds up, always maintaining the aircraft's relative position.

That's why I'm pointing out the givens.

"Always maintaining the aircraft's relative position" is a given in this question.

Then, if you say treadmill like this can't be built, then you're saying the question is bunk.

About half the people say the plane will accelerate, about half go with the no relative motion, and a few just like to stir up trouble.

I'm on reserve, so I gots nuthin' better to do.

 

[Seadogrun]

I guess a lot of pilots failed high-school physics.

Reminds me of the time I was flying with another pilot (ATP even, multiple type ratings) and I suggested we alter course to avoid the thunderstorm at our 12 O'Clock and 30 miles. He said no need... the wind was blowing from our right and the storm would be blown away by the time we got there. I tried to explain about heading vs. course and same air mass and all that and ended up just giving up. Not worth arguing I guess.

But if you have a crosswind the storm that is at your 1200 it isn't on your course because you are crabbing.

It's not the reason your friend gave, but depending on conditions he might be right.

 

[ImbracableCrunk]

But if you have a crosswind the storm that is at your 1200 it isn't on your course because you are crabbing.

It's not the reason your friend gave, but depending on conditions he might be right.

Uh oh.

 

[COOPERVANE]

That's why I'm pointing out the givens.

"Always maintaining the aircraft's relative position" is a given in this question.

Then, if you say treadmill like this can't be built, then you're saying the question is bunk.

About half the people say the plane will accelerate, about half go with the no relative motion, and a few just like to stir up trouble.

I'm on reserve, so I gots nuthin' better to do.

I completely agree with you. When I worded that question that way, it was the way I heard it and I thought it would not fly. I thought it was so obvious, any idiot could see it.

Insert "the treadmill is designed to keep the aircraft in it's relative position" and suddenly it will fly. It would not be able to keep the relative position.

 

[ackattacker]

But if you have a crosswind the storm that is at your 1200 it isn't on your course because you are crabbing.

It's not the reason your friend gave, but depending on conditions he might be right.

Well, I said it wasn't worth arguing so I'm not going to argue it... but I think you've just proved my point about high school physics and pilots. Course over the ground is irrelevant to the problem... much like wheel speed.

 

[Alltheway]

Ok now I get it, wheel speed does not matter because the plane has ole timey flapping wings

 

[Captzaahlie]

That's why I'm pointing out the givens.

"Always maintaining the aircraft's relative position" is a given in this question.

Then, if you say treadmill like this can't be built, then you're saying the question is bunk.

About half the people say the plane will accelerate, about half go with the no relative motion, and a few just like to stir up trouble.

I'm on reserve, so I gots nuthin' better to do.

http://dd01.frontierairlines.com/penguin_game/index.html

now you have something better to do!

 

[Amish RakeFight]

http://dd01.frontierairlines.com/penguin_game/index.html

now you have something better to do!

Gosh...that's a little addicting isn't it?