Imagine a plane is sitting on a treadmill, Mythbusters test it!

[KRCummings]

I can't believe people still argue this. It's very simple but so many have it in their heads that a plane is like a car. The Mythbusters message boards has several idiots claiming the test was wrong and that the plane couldn't possibly take off.
It doesn't take a scientist to figure it out. The wheels have absolutely nothing to do with the problem.

 

[Peregrinator]

For anyone still confused, try this video:

http://www.youtube.com/watch?v=4owlyCOzDiE&NR=1

Note that no matter how fast the treadmill goes, once the thrust of the engine overcomes the friction of the wheel bearings, the plane zooms forward as usual, with its little wheels spinning like mad, thinking the plane is going a gazillion miles an hour because the treadmill is going a gazillion miles an hour in the other direction, the evil and manipulative thing. As far as the rest of the plane is concerned, nothing is different this time, and the wheels are just whiny little bitches, wondering why they have to spin so much faster this time. The plane knows that it can take off any time it wants, and the bitchy wheels can complain all they want to, as long as they keep spinning.

Effectively, all a plane's wheels really do is reduce friction with the ground.

 

[Bad_Doggie]

Pulling the tarp with the truck just ADDS the tarp speed to the indicated ground speed at the wheels.

Doesn't change either the actual speed-over-ground or the airspeed.

I guess it was the best they could do with the resources they had. I was expecting a RC plane on a proper treadmill.

But, may-be they did that too. I haven’t yet seen the program.

Woof!

 

[Bad_Doggie]

The one thing I never thought would happen has happened. I agree with TURD about something!

Woof!

 

[Bad_Doggie]

1. Didn't I just read a thread about this a month or so ago?

2. The plane takes off.

3. Thank god mythbusters is around to prove physics works.

4. What the fuck is up with the "woof!"??? It's even more annoying than "Ishmeal"

Woof!

 

[Cap’n AMatrixca]

Not if it's tied down.

An airfoil only works when air is moving over it at a sufficient speed to generate a pressure differential and thus create lift. A propeller doesn't provide lift by driving air over the wings. It just generates thrust so that the entire aircraft moves through the air. You can see this with push props (where the propeller is actually at the rear of the aircraft).

See, I told you. The helicopters cannot fly contigent will never let this one go...

 

[Ishmael]

See, I told you. The helicopters cannot fly contigent will never let this one go...

Neither can bumblebees.

Ishmael

 

[Cap’n AMatrixca]

SciAm has the flawed assumptions to that one nailed unless their Brave New Political Science has gotten to the re-write already...

 

[Ishmael]

SciAm has the flawed assumptions to that one nailed unless their Brave New Political Science has gotten to the re-write already...

Bricks will fly provided you give them big enough power plants. The F-4 Phantom proved that.

Ishmael

 

[Cap’n AMatrixca]

Interesting point.

 

[Cap’n AMatrixca]

There was a book about Jimmy Doolittle's raid called, "30 seconds Over Tokyo," which should be required reading for the "it can't fly" crowd as they discuss exactly how they were able to get full loaded bombers off the flight deck...

 

[sutherngent985]

Bricks will fly provided you give them big enough power plants. The F-4 Phantom proved that.

Ishmael

Also the space shuttle. Its hard to imagine that, or a fully loaded 747 at almost 3/4 of a million pounds, can move, let alone fly.

 

[Worm]

What if I nuke your stupid plane and your treadmill. I win..I must be an LT alt.

 

[Lovelynice]

See? That was a shitty experiment because the aircraft was still moving relative to the air around it so of course it would take off once it reaches a certain speed.

Rather pointless.

Why did they make such a big hype about it, and waste so much money...

maybe the money was the reason. Reminds me of the really dumb gameshows we have in Japan.




.

 

[MNGuy]

I want to see the treadmill fly! Strap a big ass engine on that sucker.

 

[rosco rathbone]

I've been pondering this treadmill conundrum for years and the answer finally came to me. It all seems so simple in retrospect.

The jet would take off, because the thrust, which provides the forward motion, which causes the wings to generate lift, comes from the jets pushing on the atmosphere, not the wheels pushing on the runway.

The wheels are just there to reduce friction. Skis or pontoons would work just as well.

There's one special case when the plane would not take off--if it had no jet engines or propellors, and was instead relying on motorized wheels on the runway to get up to takeoff speed.

Of course a plane like that would only fly for about one second with no jet to sustain forward motion.

There are some examples of wheeled vehicles with wings, like the inverted wing on the back of race cars that generates down force. If that were turned upside down, a race car would fly briefly once it got up to a certain speed...unless it were on a treadmill.

 

[Saint Peter]

Dear Lit,

I figured this shit out in 1738.

Hugs and Kisses,
Daniel Bernoulli

 

[Peregrinator]

For anyone still confused, try this video:

http://www.youtube.com/watch?v=4owlyCOzDiE&NR=1

Note that no matter how fast the treadmill goes, once the thrust of the engine overcomes the friction of the wheel bearings, the plane zooms forward as usual, with its little wheels spinning like mad, thinking the plane is going a gazillion miles an hour because the treadmill is going a gazillion miles an hour in the other direction, the evil and manipulative thing. As far as the rest of the plane is concerned, nothing is different this time, and the wheels are just whiny little bitches, wondering why they have to spin so much faster this time. The plane knows that it can take off any time it wants, and the bitchy wheels can complain all they want to, as long as they keep spinning.

Effectively, all a plane's wheels really do is reduce friction with the ground.

I've been pondering this treadmill conundrum for years and the answer finally came to me. It all seems so simple in retrospect.

The jet would take off, because the thrust, which provides the forward motion, which causes the wings to generate lift, comes from the jets pushing on the atmosphere, not the wheels pushing on the runway.

The wheels are just there to reduce friction. Skis or pontoons would work just as well.

There's one special case when the plane would not take off--if it had no jet engines or propellors, and was instead relying on motorized wheels on the runway to get up to takeoff speed.

Of course a plane like that would only fly for about one second with no jet to sustain forward motion.

There are some examples of wheeled vehicles with wings, like the inverted wing on the back of race cars that generates down force. If that were turned upside down, a race car would fly briefly once it got up to a certain speed...unless it were on a treadmill.

Rosco, you doink. Read my shit.

 

[Bad_Doggie]

I've been pondering this treadmill conundrum for years and the answer finally came to me. It all seems so simple in retrospect.

You've been pondering this for 6 years and figured it out tonight?

Things look clearer through the bottom of a glass.

Wotcha drinking, I need some.

Woof!