Airplane on a Conveyor Belt: Solved

by alphamonkey on February 1, 2008 · 9 comments

in Uncategorized

Ah, the heated physics debate for the up-late-at-night and/or really high: Will an airplane take off if the runway is a conveyor belt dragging in the opposite direction? Mythbusters tackled the question last night, and (as Jason Kottke summed it up):

Mythbusters - Airplane

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  • elkciN

    This is one of those questions that always popped up in internet forums, and it upset me how hard it was for some people to grasp the concept that the wheels have nothing to do with anything.

    I’m glad Mythbusters finally put that stuff to rest.

  • .alphamonkey.

    I think the main sticking point is that people think of a plane’s engine as pushing the plane along in conjunction with the wheels, as opposed to those engines actually pulling the plane, with the wheels there to keep the underside paint all sassy

  • Andy Cochrane

    yeah its very easy to explain really- the faster the conveyor belt goes, the faster the wheels turn, but that doesn’t affect the plane’s speed at all.

    unless the wheels are rusty or something- if they don’t spin freely they would slow the plane down, and then we’d have a whole new pointless internet fight on our hands.

    i will say one thing- why is this a myth? when has this ever come up in real life… or in movies for that matter??? i just wonder where this all came from.

  • BAD

    I thought it was funny because air does need to pass by the wings for lift, but how much? Well apparently not much at all.

    Yep, it is true that just the power of the engine is all that is needed for lift. Once it is pulling enough only a little bit of air is needed for lift.

    I wonder if they could use this on Air force carriers? Wouldn’t help with landings tho.

  • Adam Reynolds

    “just the power of the engine is all that is needed for lift” – no, the engine pulls the plane through the air, and the air over the wings provides the lift. I don’t understand how anyone could think that a plane could take off when its air speed is zero. And similarly, why people think that a plane traveling at its takeoff speed would not take off under any circumstance. The conveyor underneath doesn’t matter at all.

  • Armageddon T. Thunderbird

    OH fer chrissakes! This sounds like one of those things dolts argue about in dive bars, shortly before falling off their stools. I guess they will have to go back to discussing the disruption to the life cycle of crops caused by Daylight Saving Time, now that it has been demonstrated that an AIRplane doesn’t give a shit how fast the ground is moving.

  • BAD

    LOL, taking my words out of context is awesome. You must win every argument. 😛

  • Armageddon T. Thunderbird

    The only variable changed by the sliding tarp was the rotational speed of the plane’s wheels. As the pilot stated, the plane took off normally. It did that because air is the medium in which it functions, and the tarp made no difference in that relationship. This ain’t rocket science.

  • Adam Reynolds

    “LOL, taking my words out of context is awesome. You must win every argument. :-P”

    I hope you were being sarcastic about this technology helping aircraft carriers, though! If you weren’t being sarcastic, then you didn’t understand the physics behind this at all, and additionally, if you weren’t being sarcastic, then your statement that I quoted was NOT out of context.

    The amount of power the engine puts out means nothing to the takeoff distance. What matters, and the only thing that matters, is the relative speed of the air over the wings and its direction being opposite to the desired direction of travel.

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