Will The Plane Fly?

[Andy Moore]

This will get em arguing at work.

Imagine a plane is sitting on a massive hypothetical conveyor belt, as wide and as long as a runway. The conveyor belt is designed to match the speed of the plane exactly but moves in the opposite direction. The engines are running at take-off thrust, the brakes are off, etc. Everything is normal save for the fact the plane is on a treadmill.

Can the plane take off?

[kitten]

you trying to start another wheel bearing thread

[Cookee]

Or reading a highly entertaining thread on OffshoreOnly.com?

[Cookee]

ps. Yes!

[Nasher]

My thoughts

The plane will move forward THROUGH THE AIR at take off speed genetating lift under its wings and take off.

However the undrcarrige wheels will revolve twice as fast for a given speed.

Unless ground force has an effect.
(The actual force, not Charlie and Tommy)

Nasher.

[Nos4r2]

Originally Posted by Andy Moore

The conveyor belt is designed to match the speed of the plane exactly but moves in the opposite direction.Can the plane take off?

Yes it'll take off. (final answer)

For the conveyer to be able to match the speed of the plane, the plane will have to be moving in relation to the ground.

[Andy Moore]

Originally Posted by Nos4r2

Assuming the tyres don't burst from moving at twice the speed they usually do then yes-the engines are pushing against the air not the ground.

So, if you were observing it from an adjacent field, it would appear to vertically take off?

[Nos4r2]

I think there's an essential parameter missing here.

Is the conveyer designed to match the plane's speed over the ground (in which case it'll take off)
OR
Is it designed to match the plane's speed on the conveyer (in which case it'll never get any airflow over the wings and won't take off).

[Cork Rib]

May'be i'm going against the run of things here, but i don't think it will take off.

An aircraft requires airflow over/under the wings to create lift. In your scenario, the only thing moving is the treadmill and the wheels therefore there is no airflow created.

The thrust of the engines does not become part of the equation as the aircraft is stationary

All IMHO

Jon

[Nasher]

The plane is not stationary, it will move forward as usual, and hence have airflow under its wings.

The conveyer is attached to the ground and only the plane wheels are touching the conveyer, they just need to go faster.

This is all about the planes movement relative to the air around it which is absolutly normal.

Never heard of an air conveyer.

In a wind tunnel where the air was moving the plane would lift vertically.

Nasher.