The plane's engines generate thrust which pushes the plane forward. You could have the conveyor moving the wheels at 20 times the speed of the airplane and make almost no difference. The engines provide thrust in relation to the plane's position in the air, not on the ground.

Think of it this way: If the wind is blowing against the airplane's forward motion, does the airplane stop flying when it's groundspeed reaches 0? No. the plane is still flying at whatever speed the engines provide thrust for, only forward progress on the ground is nil.

Now take the same plane and put the wind behind it. Now it's going as fast as the engine provides plus whatever the windspeed is in relation to the ground. The airplane doesn't know it's going any faster.

If the airplane is on the ground as in the conveyor scenario, the wheels are simply tracking along the conveyor minding their own business having nothing to do with the rest of the airplane's operation. They can go faster or slower and it makes no difference to the plane. The engine's thrust provides forward motion in relation only to the air around it, and no consideration is taken to the speed over the ground, however it may be perceived.

Here's an interesting example. When I was in flight school we used to have to chain the wings of our planes to the ground. This was done because the wind could (and I saw it happen on more than one occasion) pick the plane up off the ground. At this point the aircraft was indeed flying, even though chains were holding it in one place in relation to the ground. It's quite interesting to be walking on the tarmac and suddenly every small plane appears to jump up into the air and hover for a bit, then settle back to the ground. Sometimes there might be one porpoising because a flight control surface was locked or jammed or something.

The bottom line is this; If the conveyor had anything to do with the flight of the aircraft, you could assume that merely leaving the ground would cause the loss of all forward thrust and the plane would come crashing back to earth.

Thank you clay. <img src="/forums/images/graemlins/kewl.gif" alt="" />

Plane takes off irrelevant to ground speed.

Thread closed.

The answer is no, obviously, for reasons already mentioned.

Another way of approaching the answer is, if it were possible, our runways would be a lot shorter. <img src="/forums/images/graemlins/wink.gif" alt="" />

It isn't going anywhere.

It needs air speed in order to generate lift. It doesn't matter how hard it spins its wheels, if there isn't air moving over the wings it is just going to waste a lot of money. <img src="/forums/images/graemlins/lol.gif" alt="" />

No. However, if we put a submarine in an endless swimming pool, I think it would be able to float.

The earth will rotate backwards due to the conveyerolis effect, how much the earth rotates will depend on the the angle of the conveyer in relation to the earths rotation, direction and distance to the equator.

If the treadmill was placed on the north pole the plane would rotates around on the treadmill in a counter clockwise direction.

Kevin

I cannot imagine that your typical small passenger plane, or even large jet liner could take off. The only way I see you lifting yourself off of the conveyor is with a plane that has enough thrust to take off from a standing start, and I'm not familiar with anything like that. You need lift at the wings, and no matter how fast your turn that prop, if you cannot get forward momentum you are not going up. At least that is how it plays in my head.

- Jim

Im a private pilot and worked on F-18's in the Marine Corps.

The plane takes off when the lift of the wing overcomes gravity. This is a function of airspeed, nothing to do with the ground at all.When you take off you set the flaps to make the wing have more curve, this increases lift. As long as air is moving over the wing the plane will take off as long as it's not chained down. Lift is created by pressure differental. Small airplanes are always chained down a Cessna 172 will take off around 75mph. I've seen them fly two inches off the ground during a storm right in place while being chained.

On Aircraft Carrier operations you always take off into the wind to help with the airspeed. The ship also helps by going fast into the wind. On a fully loaded combat air patrol you need very bit a help to get loaded bird off the ground. I've seen the fat ones disappear below the deck after launch and then climb. Those Navy and Marine pilot have huge brass balls



<img src="/forums/images/graemlins/patriot.gif" alt="" />

Kevin...you have two compass on a aircraft one is the standard compass the other is called a Directional Gyro. You have to reset the directional gyro every so often because of the conveyerolis effect.

Well that how it was working out in my mind too...but when I thought about it too much, I started to have doubts...and the other guys are just as positive it WILL take off. This post has a de je vu quality to it...didn't we have something similiar going here a few years ago? <img src="/forums/images/graemlins/smile.gif" alt="" />