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Plane on a Conveyer Belt

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The reasoning used to make this a question is this: if the bearings in the wheels (for the airplane on the converyer belt) and in the main hub (for the rotor) are completely frictionless, then the conveyer belt would only spin the wheels on an airplane and the hull of the helicopter would spin under the stationary main rotor. In both cases, there is not airflow of the respective airfoils, therefore no lift, therefore no flight.


Now, it's well known that no bearing is 100% frictionless, but the still have to be "smooth" to work well; maybe they're smooth enough so that the effect would be the same as for frictionless. Clearly this isn't the case - even the tiniest fraction of friction will allow some of the power from the belt/turntable to be applied to the motion of the aircraft. It'll take a lot longer to get where it's going (flight), but it *will* get there all the same.

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For the helo on a turntable




a) the turntable is freewheeling it would have no impact (except during spool up) as the tail rotor would counteract torque just like in flight. Spool up would be the big risk until the tail rotor has enough RPM to be effective.


B) if the turntable is powered and rotates in the same direction as the rotors you could damage the helicopter because the blades would be rotating faster then their operating RPM


c) if the turntable is powered and rotates in the opposite direction fast enough the rotor will not generate enough lift.


The whole plane on a conveyor thing is completely retarded. The wheels don't provide the forward force, the propellor does. Even if the wheels were locked and unable to rotate, if the available forward thrust is sufficient, it would easily overcome the friction generated by the tires dragging over the ground. Once tires begin to slip the coefficient of friction is reduced so as the tires start sliding over the ground the resistance actually becomes less.

Edited by Fiasco
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I must chime in on this one.


If you look closely at the planes on the belt, you'll see that the planes were not staying in the same place, but moving forward faster than the belt going the other way. This then led to airflow over the wing creating lift. The planes then became airborne.


I can't believe the Mythbusters actually confirmed that myth. I'm hoping they'll take another look at that and possibly reverse their conclusion.


I'll shut up now.



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I am so envious of the avitar, have been for a long time!


Mythbusters was hogwash, the aircraft was moving and creating lift as it left the "conveyer", you could see it in all the videos. But its still fun to watch!

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  • 4 months later...

The point of the mythbusters episode is that the propeller pushes against the air and moves the airplane. The wheels don't matter at all. The conveyor belt could be moving at 200mph and the plane would still take off. The wheel bearing friction is a very minimal effect for the takeoff of an airplane.


Now the heli on a turntable... that won't work because you can essentially "stop" the blades from spinning.

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