Mythbusters/airplane on a treadmill.

[in2fords]

WOW, is it really that hard of a concept? the prop gives "forward movement", the wheels are just there for the ride and have no affect on the plane or its "forward movment", atleast in the boundries of this experiment/theory. I bet at just over idle the plane would still move foreward. the plane doesnt even know the conveyor belt is there!

I could understand if the engine was turned off and the props didnt move then the conveyor moved while the plane stood still, then it would not leave the ground.

Beating a dead horse? this thing is so bruised up its being ground into hamburger!

 

[JeepFreak21]

Damnit, that reminds me... need to get a check in the mail this week.

Billy

 

[goodburbon]

this whole thing is soooo stupid

I didn't read through the thread and I actually didn't catch the episode on tv but i did just watch the link posted and they totally defeated the whole purpose of the myth.

Once the plane moves forward on teh conveyor it is not proving its own lift by moving forward thus pushing air under its wing.

the point of the myth was that with the conveyor moving backwords and the plane with enough prop speed to match the speed going forward of the conveyor that the plane would not take off.

All they did was provided a conveyor and then had the guy in the airplane throttle faster than the conveyor was moving thus providing forward movement and then giving lift.


Bahhh I can't believe this thread has this many pages for this stupid myth lol

:dunce:

 

[dave92cherokee]

I just read through all 21 pages and feel like my brains gonna melt down. The way they did the myth then of course the plane's going to take off, the plane and "conveyor belt" are moving in the same direction. That's a no brainer that once there's enough lift on the wings it will take off. What I was getting from the first dozen pages though was that the plane whatever type would have the engines throttled up to make it go say 150 mph and that a "conveyor belt" would be under the wheels going in the opposite direction at 150 mph making the plane stay stationary and thus not having any lift under the wings. In that case then of course the plane will not take off because there would be no air movement and as such no lift so no flight.

 

[Hammered]

The way they did the myth then of course the plane's going to take off, the plane and "conveyor belt" are moving in the same direction.

Huh?

TWhat I was getting from the first dozen pages though was that the plane whatever type would have the engines throttled up to make it go say 150 mph and that a "conveyor belt" would be under the wheels going in the opposite direction at 150 mph making the plane stay stationary and thus not having any lift under the wings. In that case then of course the plane will not take off because there would be no air movement and as such no lift so no flight.

I had the same mental image at first. But think about it... AIR IS MASS... and the WHEELS ARE FREE SPINNING (not driving) the props pull through the AIR NO MATTER WHAT IS GOING ON UNDERNEATH.

hasta

 

[goodburbon]

I just read through all 21 pages and feel like my brains gonna melt down. The way they did the myth then of course the plane's going to take off, the plane and "conveyor belt" are moving in the same direction. That's a no brainer that once there's enough lift on the wings it will take off. What I was getting from the first dozen pages though was that the plane whatever type would have the engines throttled up to make it go say 150 mph and that a "conveyor belt" would be under the wheels going in the opposite direction at 150 mph making the plane stay stationary and thus not having any lift under the wings. In that case then of course the plane will not take off because there would be no air movement and as such no lift so no flight.

:dunce:

 

[97XJ Jeeper]

HastaHastaHastaHastaHastaHastaHastaHastaHastaHastaHastaHastaHastaHasta

 

[IslanderXJ]

Bwa ha ha..... :roflmao:




wait...


Do they really believe what there saying?

FAIL​

The treadmill doesn't matter, thats kinda the point in the myth. It tricks people who dont understand how flight works.
The wheels free spin, think about it like the plane is levitated by magnets or something so its not touching the ground (eliminating the wheel part of the equation, which isn't in the equation anyway unless the brakes are on), just a few feet above the giant treadmill. It will start to move as soon as the props/tubines start spinning... PERIOD

 

[Lowrange2]

lol

 

[srimes]

Ok, so if I put my Jeep on a giant treadmill going backwards at 50 mph, and I drive forward with a wheel speed of 100 mph, what kind of gas mileage will I get?

 

[IslanderXJ]

Ok, so if I put my Jeep on a giant treadmill going backwards at 50 mph, and I drive forward with a wheel speed of 100 mph, what kind of gas mileage will I get?

See your asking the wrong question... you should be asking why you rig hasn't fallen apart yet since its going 100mph!!!

 

[JeepFreak21]

The way they did the myth then of course the plane's going to take off, the plane and "conveyor belt" are moving in the same direction.

But they weren't going the same direction... and it did take off.
Billy

 

[oo7ravisXJ]

o2bgpn said it best in my opinion

This doesn’t have to be an airplane question. I could ask the same question using a rock and a string: Put a rock on a conveyor belt and tie a string to the rock. Now someone off the conveyor belt pulls the rock using the string. At the same time turn on the conveyor belt. What will happen to the rock? It’s obvious the rock will move forward because the motive force of the rock (person off conveyor belt pulling string) is independent of the conveyor belt. In other words the rock is not using the conveyor belt to move, it’s using the person pulling the string.

Same with the airplane. The motive force (propulsion caused by the prop, or even “string” in the case of a glider) is independent of the conveyor belt. The fact that an airplane will fly if it has a propulsive force great enough, (independent of the conveyor belt or a stationary tarmac) is a by-product of its shape. The fact that the object on the treadmill moves “forward” is a physics question.

Leave it to prop jockeys to make a problem harder than it needs to be. I call Lowrange the winner on this one.