It's been a while - and we have new blood...

[TonyN]

[GBV8]

I've changed my mind. It will take off regardless of treadmill speed. But then you all knew that anyway

[Albannach]

{Andy you're a cock}

I'd be worried if he got reasonable.

[schrodingers-cat]

It's the difference in pressure above & below the wing that causes lift.

Yeah, so the big fan i previously mentioned is blowing air over the wings. The air going over the top has to travel further so the pressure above the wings is lower than the pressure under so the plane takes off. seems feasible to me tho what purpose a plane that just went up and down would be i don't know

[flounderbout]

Yeah, so the big fan i previously mentioned is blowing air over the wings. The air going over the top has to travel further so the pressure above the wings is lower than the pressure under so the plane takes off. seems feasible to me tho what purpose a plane that just went up and down would be i don't know

That is why planes (and indeed flying things generally) take off and land into the wind. Airspeed is what counts to generate lift, not groundspeed. Airspeed = groundspeed + windspeed if heading into the wind. Therefore taking off or landing into the wind reduces groundspeed for a given airspeed.
Have a sufficiently mahoosive headwind and an aircraft with a low required liftoff airspeed and you could certainly have a plane that takes off at zero groundspeed.
Just as a simple kite on a piece of string flies at zero groundspeed as soon as the airspeed (made up solely of windspeed) is sufficient.
That is why if you fly a Cessna or similar into a big enough headwind you can register zero or even negative groundspeed... http://www.youtube.com/watch?v=CVfA_e3wfFE
And that is why the last time I was in a Cessna I was very anxious to jump out of it as soon as possible.

[TonyN]

It won't take off.

Com'on H, you know all about feeding people limited facts to get a wrong answer. It's what you do for a living!

(Oh, and Red Truck passed MOT, but alt is toast, I think I have one but havn't found it yet.)

[flounderbout]

It won't take off.

Com'on H, you know all about feeding people limited facts to get a wrong answer. It's what you do for a living!

(Oh, and Red Truck passed MOT, but alt is toast, I think I have one but havn't found it yet.)

That is wholly unfair. The only time the wrong answer ever results is when the Judge disagrees with me. When he agrees, the sword of justice glimmers a little brighter in my hand, the birds sing, and all is well with the world. But sometimes judges are idiots...

Many thanks re ole red. Any idea when you may be all set? Good to see you briefly the other day. You and Linda must pop by when you have a bit more time so the girls can fawn over puppies (don't even think about it gwh200...!).

[gwh200]

Too damm late H.

[Bender71]

That is why planes (and indeed flying things generally) take off and land into the wind. Airspeed is what counts to generate lift, not groundspeed. Airspeed = groundspeed + windspeed if heading into the wind. Therefore taking off or landing into the wind reduces groundspeed for a given airspeed.
Have a sufficiently mahoosive headwind and an aircraft with a low required liftoff airspeed and you could certainly have a plane that takes off at zero groundspeed.
Just as a simple kite on a piece of string flies at zero groundspeed as soon as the airspeed (made up solely of windspeed) is sufficient.
That is why if you fly a Cessna or similar into a big enough headwind you can register zero or even negative groundspeed... http://www.youtube.com/watch?v=CVfA_e3wfFE
And that is why the last time I was in a Cessna I was very anxious to jump out of it as soon as possible.

Im with 'im + paragliders dont need ground speed to take off if the wind speed is strong enough :-)

[Mork]

The plane will take off, but the wheels of the plane will be spinning twice as quickly as they normally do.

To explain it using different styles.
Hold a toy car on a moving treadmill, you can move the car against the treadmill, but the wheels will just be spinning more.

A normal car on a treadmill will not move. But the cars movement is powered by the rotation of the wheels. A plane is powered by the jets/props, which aren't fixed to the rotation of the wheels.

The wheels just hold the plane off the ground, they don't provide any power/thrust.

If you want to get very technical it's likely that there might be some small impact from the treadmill based on the efficiency of the bearings in the wheels, there might also be some question about the force required for initial movement before the wheels are spinning – but it's negligible for a forum riddle,

A floatplane will not take off against a fast moving river because the floats are attached to the plane, they aren't spinning like wheels. Any push on the floats will directly effect the plane because there are no wheel bearing sort of thing separating the plane from the floats.

[Koi]

wheels no wheels still wont take off,
planes engines push plane forward to say 50mph where enough air flow is achieved then lift is achieved.
Pane > 50mph
Belt < 50mph
= no movementr in either direction, without movement there is no air flow over the wings so no lift

[Wolfracer]

See post 5...
S'got NOWT to do with the the conveyer. It might as well be a sheet of ice, water, or snake oil for that matter!

[Koi]

See post 5...
S'got NOWT to do with the the conveyer. It might as well be a sheet of ice, water, or snake oil for that matter!

I did it said ' I think '

and ice is static the conveyor ain't

[gwh200]

I still think we are missing some fundamentals here.

The most important

A. Albannach is a right cock.

B. See A.

[Wolfracer]

I did it said ' I think '

and ice is static the conveyor ain't

You tried running on ice?!