Once and for f*cking all....

[Erick]

Bottom line, we need to make too many assumptions. More information is needed to properly understand. If Mythbusters can do it, half the people who said it wouldnt happen are picturing a different scenario in their minds.

[psloan]

I understood and mentally worked out the mechanics of a scale model and parameters of my concept when I was seven. The only limiting factor is friction resitance caused by the tires traction from the increased rotations and the extra heat and resistance placed on the wheel bearings. If the wheel bearings are say made to spin at a maximum rotation of 2000 rpm and the bearings typically spin at 1200 rpm when the plane acheives minimum lift to take off then there would be a problem if the conveyor belt was moving fast enough to spin the wheels at that speed and while the plane was exerting enough thrust to remain in a stationary position then the bearings would need to spin at 2400 rpms by the time the plane attains minimum lift. The bearings would overheat and the plane would dive on to the conveyor like on jordos post. But assuming the bearing are strong enough and the tires don't explode from exceeding their speed rating then the only limiting factor would be the additional thrust required to keep the plane in a stationary position which is very little since it does not need to overcome wind resitance. Just think of how much better you mpg on your car would be if there was 0 air in the atmosphere and you were driving on flat ground. you would get like 80mpg.
Please excuse any grammar or spelling errors.

All this looks to be correct - but i'm sure wheel bearings and tires on planes are built to last.

[einstein57]

I understood and mentally worked out the mechanics of a scale model and parameters of my concept when I was seven. The only limiting factor is friction resitance caused by the tires traction from the increased rotations and the extra heat and resistance placed on the wheel bearings. If the wheel bearings are say made to spin at a maximum rotation of 2000 rpm and the bearings typically spin at 1200 rpm when the plane acheives minimum lift to take off then there would be a problem if the conveyor belt was moving fast enough to spin the wheels at that speed and while the plane was exerting enough thrust to remain in a stationary position then the bearings would need to spin at 2400 rpms by the time the plane attains minimum lift. The bearings would overheat and the plane would dive on to the conveyor like on jordos post. But assuming the bearing are strong enough and the tires don't explode from exceeding their speed rating then the only limiting factor would be the additional thrust required to keep the plane in a stationary position which is very little since it does not need to overcome wind resitance. Just think of how much better you mpg on your car would be if there was 0 air in the atmosphere and you were driving on flat ground. you would get like 80mpg.
Please excuse any grammar or spelling errors.

[Jesse30]

oh jesus christ. just watch the episode and stop whining about it.


p.s. it will not take off.

[2002maniac]

Air speed is key. Think of this entire problem in term of the plane pushing on the air, with only the friction of the wheels holding the plane back. When a plane takes off on a normal runway, the friction is a value, say F. So, if the power of the engines remains constant, then the only think that changes is that the force of friction F is double, to 2F. So all that the plane would need is perhaps some more runway, depending upon the force F. So essentially the force of the thrust of the engine T needs to be greater than F/2, T > F/2 or 2T > F. However the force of friction F is insignificant to the wind resistance, therefore it can be assumed to be zero, and thus, miraculously, the plane will take off. High school physics boys.

my 10yr old brother understands this. DUH PEOPLE :)

[Axxe]

Air speed is key. Think of this entire problem in term of the plane pushing on the air, with only the friction of the wheels holding the plane back. When a plane takes off on a normal runway, the friction is a value, say F. So, if the power of the engines remains constant, then the only think that changes is that the force of friction F is double, to 2F. So all that the plane would need is perhaps some more runway, depending upon the force F. So essentially the force of the thrust of the engine T needs to be greater than F/2, T > F/2 or 2T > F. However the force of friction F is insignificant to the wind resistance, therefore it can be assumed to be zero, and thus, miraculously, the plane will take off. High school physics boys.

[Erick]

how fast is the belt moving erick?

LIGHTSPEEDZ

[Funkmasta]

Also, I need to know if the stewardess is hot. If not, is the captain drunk?

If you answered "yes" to either of the above questions, then, no, the plane will not take off.

[Sean]

I only have one word to say...

Wow.

[DarkWing6]

It all depends on how you are measuring the speed of the plane. If you are measuring ground speed then it will not take off. If you are measuring air speed, which is the right way, then it will take off.

For the record I want to be in saying it will take off.



Seacrest out.

[Funkmasta]

how fast is the belt moving erick?

[psloan]

What if there are a million air scoops from a WRX STI attached to the conveyor belt to help create airflow?

Airflow inside the conveyor belt?

[e34john]

What if there are a million air scoops from a WRX STI attached to the conveyor belt to help create airflow?

[psloan]

For all the people who actually defend the plane taking off.

What you're stating leads to one conclusion.

The conveyor belt is just as powerful as 2 jet engines.

If the above is not true, the plane will win.

[Erick]

For all the people who actually defend the plane taking off.

I'm still saying no. Although there is a chance, it is something clear. (How I love keeping this thread alive)

If you put a plane stationary on the belt, and start moving the belt, the plane will be dragged back for the simple fact that there is friction between the belt and the wheels. Therefore, there is SOME sort of force that will be holding the plane back, even if it's independent from the thrust of the motor.

So the plane will be required to have a LOT (depending on how much friction there is, ice runways don't count) more thrust than normal in order to be able to counter that extra drag that will still be there. So it's possible, but I dont think anything other than a fighter jet could overcome that.

Also, quick fact. Not saying this will happen, but it comes down to this: if the wheel spin from the plane remains the same as the belt (moving backwards), then the plane's speed will be 0, and it will not generate any lift whatsoever. For it to take off, it will need to overcome this.

The odds are seriously against it how I see it. So I say no, under normal circumstances, it will not take off.

Oh, and it needs a belt the size of a real-life runway... but that's a given.

- Erick