Of course the airplane were going to get to fly.
I dont know write in english physacal therms but i ll try. The airplane gets the speed that it needs to take off independent of the conveyor because his speed doesnt come from the tires. so the only way of it doesnt take off was if the friction between the tire and de conveyor was shorter than the rollings of the tires.
bye

If only someone had said that earlier.

This really was a silly and pointless myth.
The "no fly" believers really need to give their heads a shake. How obvious does it have to be...the speed of the conveyor has absolutley NO effect on the planes ability to take off. It doesnt matter if the conveyor is traveling at 500 mph the plane will still take off as if it were on stationary tarmac.
Stop embarrasing yourselves by suggesting the conveyor speed didnt match the planes speed, IT HAS NO EFFECT...end of.

quote:

the speed of the conveyor has absolutley NO effect on the planes ability to take off

The no-flies believe that their is some magical type effect.

New on this forum so Hi everyone, I just had to answer to this one.
The conveyor is mostly irrelevant in making an airplane fly. Mostly because the friction from the landing gear mechanism might slow down the plane a little bit (kind of hitting the brakes while at full throttle speed) but not much. The airplane takeoff speed is not measure by ground speed but by air speed (Airplane speedometers are measure that way for a reason.. IAS or Indicated Air Speed)so as soon as the airplane reaches the airspeed necessary to take off it will. I was surprised at the pilot´s remarks that the plane would not take off since every pilot knows that Air speed is what matters in Aviation. It does so much that in theory an airplane could fly backwards relatively to the ground if the wind speed is greater than the airspeed necessary for the airplane to fly, of course that is very difficult to achieve since those wind speeds would make the plane not only very difficult to fly but very dangerous. (we are talking +60 Knots winds).
Anyways the airplanes lift comes from air speed not ground speed so the conveyor has nearly no effect on the ability of an airplane to take off
Rod

Well… how do I put this without directly insulting the pilot……… the plane the Mythbusters chose to test with was an ultralight, and in the USA, ultralights don’t require any training to operate.

quote:

Originally posted by ratranger:
Well… how do I put this without directly insulting the pilot……… the plane the Mythbusters chose to test with was an ultralight, and in the USA, ultralights don’t require any training to operate.

Sorry but N110MJ is most likely NOT an ultralight.
It is a registered Experimental Rans S-5 indicating a Rotax 503 DCDI.
it does NOT meet the requirements for an ultralight. it weighs too much empty, carries too much fuel, has a stall sppeed that is too high, and is capable of traveling faster than 55 knots.

Well dang… what can I say… I guess he has no excuse, then.

And, whoops. I got ahead of myself. I don’t have any excuse either.

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Has anybody ever studied the aerodynamics of flight? It doesn't matter how fast the wheels are moving against the conveyor, if the conveyor is matching that speed and holding the plane effectively stationary - It simply will not take off unless the WINGS have sufficient relative wind moving across them to achieve lift.

Sigh... you say you're a pilot and a scientist with strong physics background? Either that is a lie or you're missing the entire point here.

First, as long as the wheels are free to spin at any speed, it makes no difference how fast the conveyor belt is traveling. It has no effect at all on the thrust of the engine. The conveyor belt could be moving backwards at 1000 mph, as long as there is thrust from the propeller pulling the plane forward, it will simply mean that the tires will be spinning faster and faster.

For example... let's assume this entire scenario is played out with a car: If a car accellerates to 50 mph at the same time a conveyor belt below it is moving the opposite direction at 50 mph, the car will, for all practical purposes, be sitting still. The tires are spinning at the same rate as the conveyor belt, and because the tires are DIRECTLY RESPONSIBLE for propelling the car forward, the car cannot move.

In the plane, the tires serve only one function. They keep the plane off the ground. That's it. Nothing else. They are free rolling, and they have nothing to do with the forward movement of the plane. If the tires were powered by a power plant such as and engine, and they rolled the plane forward to generate the air under the wings, then yes, this would be different, but that would be one VERY short flight indeed, once the wheels left the ground, right?

So in this case, the lift is created by the air being forced behind the plane from the propeller, not from the wheels... they can turn 200 mph, 300mph, makes no difference, as long as there is thrust from the propeller, the plane will move forward, regardless of the rate at which it's tires are spinning, and will, therefor, take off.

Simple logic, as many others have pointed out.

One way this myth SHOULD have been tested instead of with a tarp is to have used free spinning rollers under the tires, the type they use to benchmark engines on cars.

If there were rollers under the tires, the tires could freely spin at any speed without any issues.

It would, of course, came to the same result... the thrust from the propellers would have pulled the plane forward, and the wheels, if not held in place somehow, would have simply come off the rollers. I suppose this could have been dangerous, but it's an idea.

I Don't kno if im right but this is how i look at this, the wheels are free rolling so they can go up to any reasonable speed, so the wheels can roll freely and handle the speed of the convayor belt and the prop. can give it an extra boos to take off.

Boost*

quote:

Originally posted by Myth Busters Good fan:
I Don't kno if im right but this is how i look at this, the wheels are free rolling so they can go up to any reasonable speed, so the wheels can roll freely and handle the speed of the convayor belt and the prop. can give it an extra boos to take off.

The way they did the final test was all wrong, the plane should have been stationary. It was like if the conveyor belt was moving at 1 mile per second. The plane was moving and thus causing wind resistance on the winds, which was the whole idea, it's not about tires. If anything, the conveyor belt would have been moving FASTER than the plane (pulling it backwards), that would have been interesting to see.

The idea from 2 posts above is great to test it again.

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The way they did the final test was all wrong, the plane should have been stationary.

No, it should not have been... please read the explanations.

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Originally posted by Pioneer:
This really was a silly and pointless myth.
The "no fly" believers really need to give their heads a shake. How obvious does it have to be...the speed of the conveyor has absolutley NO effect on the planes ability to take off. It doesnt matter if the conveyor is traveling at 500 mph the plane will still take off as if it were on stationary tarmac.
Stop embarrasing yourselves by suggesting the conveyor speed didnt match the planes speed, IT HAS NO EFFECT...end of.

That is not how the "no fly"-believers think. The "no fly"-believers actually listenned to the details of the myth "If the plane and conveyor were both travelling at the same speed, would the plane take off?" No it would not. But what they really tested was would the plane take off if the plane was given the same thrust as when it would take off on a runway. Thrust doesn't equal speed in this case and as you can see from the episode, the speeds don't really match as the plane is moving forward, giving the plane a speed of the conveyor plus the speed it's going forward (in relation to surface it's rolling on). This is really a question of how you understand the myth. Would the speed of the plane and conveyor really match (as said in the myth) tha plane would not move forward and would not take off.

And when you said that the speed of the conveyor doesn't matter you are right. But the relations between the plane and conveyor does matter because even if the conveyor was travelling at 500mph and the plane could take off, the plane would still be moving with a higher speed (500mph plus the speed the plane is moving forward in relation to the ground). So you kinda missed the point. The myth clearly said that the converoy and the plane would have to move with the same speed, which didn't happen here.

quote:

That is not how the "no fly"-believers think. The "no fly"-believers actually listenned to the details of the myth "If the plane and conveyor were both travelling at the same speed, would the plane take off?" No it would not. But what they really tested was would the plane take off if the plane was given the same thrust as when it would take off on a runway. Thrust doesn't equal speed in this case and as you can see from the episode, the speeds don't really match as the plane is moving forward, giving the plane a speed of the conveyor plus the speed it's going forward (in relation to surface it's rolling on). This is really a question of how you understand the myth. Would the speed of the plane and conveyor really match (as said in the myth) tha plane would not move forward and would not take off.

Reading a little difficult for you? There's 217 pages explaining that the speed of the plane (25 mph) *was* the speed of the tarp (25 mph). The speeds *did* match. There's also 217 pages explaining why the belt can *not* hold the plane stationary.

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Originally posted by roofingguy:
Reading a little difficult for you? There's 217 pages explaining that the speed of the plane (25 mph) *was* the speed of the tarp (25 mph). The speeds *did* match. There's also 217 pages explaining why the belt can *not* hold the plane stationary.

Do you really think that if the plane was travelling at 25mph in relation to the conveyor and the conveyor would be travelling at 25mph to the opposite direction that the plane would move in relation to the ground? Wow, you just don't get it, huh?

why is this still being discussed?

quote:

Originally posted by Charles_Skyline:
why is this still being discussed?

Mainly because I live in Finland and so I just saw the episode the first time

Sorry, its just 217 pages of the same thing...

it works because the wheels aren't motorized by the motor. IT doesn't matter how fast the belt is going.

End of topic.