Mythbusters - Plane on conveyor belt the practice!

Mythbusters test the myth!

Category:

Education

Tags:

• mythbuster
• conveyor
• loopband
• plane
• vliegtuig

[stulax18]

If the truck pulls the belt at 20 mph, and the pilot sets his plane to move forward at 20 mph, the wheels will then move at 40 mph to keep up with the two. The engine speed determines the forward thrust, not the wheel speed.

[innersilencedotcom]

@dnebdal - Yes, you are right, I take it back. I was really tired and therefore a bit too stupid when i wrote these comments. The takeoff IS indeed possible, since the traction is in the propeller NOT in the plane's wheels. The propeller pulls itself (and therefore the plane too) forward, by gripping on the air. The plane WILL takeoff normally but the wheels will spin twice the normal speed cause the belt is moving back. So belt or runway, it would take the same distance to build lift and fly.

[PersonalRaineri]

This myth is retarded. Shame on you myth busters!

[Deekity]

...oops. As I was saying, naysayers are hung up on wheel friction. They just cannot grasp how little force is necessary to overcome this, thereby negating it. I'd bet they'd all be willing to admit a hovercraft with wings could take off on the same conveyor belt. Just hung up on wheel friction.

[Deekity]

@Yairgeva7 if you think the "tiny" amount of friction present in the gear is enough to keep the plane stationary, you're an idiot. That's what keeps the naysayers from "getting" this whole concept. Obsessed with

[matesakoid]

If the airplane will be moved to the air by speed of his gear it will not work, but propeller does not have anything common with gear :)

is stupid to count apples and pears together :)

[tenou213]

Okay, so assuming the conveyor belt (and hence the runway) is the length of the plane, the aircraft would just tip over and crash. If the the conveyor belt was the length of a common runway, then it would still build up speed - wheels be damned.

Conveyor belts are a bad idea though. Wind tunnels would work much better.

[YairGeva7]

People who support this "bust" still defend it by saying the plane is not effected by the ground,

well i call bullshit, do you really think the wheels and the gears that connect them to the plane don't create any drag via friction at all? you think that if the planes engine was OFF and the belt was moving back, that the plane would just remain stationary?

the wheels & gears aint perfect. a belt moving back fast enough would overpower the planes engine, it will not move forward/liftoff.

[jetengine7]

@innersilencedotcom Torque is irrelevant when it comes to planes. We're not talking about cars. Plane engines do not send any torque to the wheels. Airplane engines produce thrust. They push air backwards to move the plane forward, just like a swimmer pushes water backwards to go forward. They act on a fluid: the air. Planes DO NOT push backwards on the ground like a car does and therefore, are not affected by the ground's movements.

[jetengine7]

@MegatronSmurf Do you really need to see them do it to be convinced that the plane will takeoff? It's basic physics. No conveyor belt can stop an airplane from taking off because no matter how fast the conveyor belt is moving, the plane's wheels will match the belt's speed and cancel out the backwards force. The engines push air backwards to move the plane forward, just like a swimmer pushes water backwards to go forward. Planes DO NOT push backwards on the ground like a car does.

[jetengine7]

@Phray81 If there was a fan behind the plane, then you would have a tailwind which would make it harder for the plane to takeoff because you're moving the air in the opposite direction that it's supposed to relative to the wings. That's why planes always takeoff into the wind.