i just saw a preview for a new mythbusters next week. they are going to do the "can a plane take off on a conveyor belt" myth. I thought this would interest you guys since there was a huge thread on this before...

Yeah, and hopefully this time the episode will actually air when they say it will!

They drag a long tarp with a vehicle in the opposite direction of the plane on the runway.

Link to preview...

bracing self for another 22 page thread on this stupid concept.

OK. Ready.

No way dude - It'll take at least 60 pages

It's not a question of where he grips it. It's a simple question of weight ratios. A 5-ounce bird cannot carry a one pound coconut.

Not even on a conveyor belt?

The plane would crash like a lead balloon. Wait...

An African Swallow can!

But can he on a treadmill?

I still don't get why this is such a mystery to people...

I'm not getting into the debate at all, I just think that it's a dumb concept if you understand the physics involved with flying a plane.

Hell no, the treadmill totally negates the motion of his wings and all the physics in relation to said movement

"But the Aftrican swallow is non-migratory."

Then what's it doing in a temperate zone?

Maybe they can do Heath Ledger on a conveyor belt and we can get a 100 pages! :rolleyes:

The lead balloon one was retarded. Tissue paper thin lead? I don't think that was the original intent of the saying.

Make that lead balloon's thickness the same mil as a regular balloon and see what happens...

Are you watching the plane episode right now? You "it won't ever fly" bitches definitely owe us smart people some beers...

I don't buy it. The conveyor wasn't matching the planes speed

He could be driving 50 MPH and the damned plane would take off...did you pay attention to the scale test with the real treadmill??? The put it on max speed and the plane ran right off the end of the treadmill...oy vey.

Gimme my beer.

Or the example with the RC car on the treadmill??? The wheels of a plane are not powered, they're free spinning for all intents and purposes. Fuck me..

There's no cure for stupid.

If it matched the speed then why did the plane roll along on the conveyor before taking off??

What part about the engine doesn't power the wheels do you not get? They illustrated it perfectly during the scale test and again with the RC car on the treadmill...

OMG dude, seriously? the treadmill could have been doing 100mp and the plane STILL would have "rolled along" on the belt and taken off.

I think what he is getting at is there is no physical way possible for a treadmill to match a planes forward speed. You cannot get it fast enough. Even though the resistance is very low in the wheels of that yellow plane they used a jetliners would be much higher. But I still think the possibility lies in the fact if I had unlimited power to power a treadmill and could say ramp it up to 10,000 miles per hour to match a planes 100 miles per hour take off speed (examples there not saying takeoff for a jetliner is 100mph) that my theory of the wheels blowing up or failing would keep the plane from taking off.

I am not debating nor have I ever debated the fact the plane would or could move.

Thats what I'm getting at. I have not debated on this before now as well. Nor did I see the whole episode. So I'm not going to debate about it now anyway. But you guys are way too emotional about this

I haven't watched the MB episode yet, so I don't know what they found out, but I've said this before (in the other thread).

The real answer to whether a plane on a conveyor belt can take off is "It depends".

Many commercial aircraft require an airspeed of about 120mph to take off. (Light aircraft such as a Cessna take off at lower speeds.) If a treadmill moves exactly opposite to the aircraft's acceleration, then the mere fact that the treadmill moves at all implies that the plane is also moving. As the plane accelerates on the treadmill, the wheels and tires will be rotating at TWICE the "treadmillspeed" of the aircraft. Assuming ZERO windspeed, then groundspeed (which is not the same as "treadmillspeed") equals airspeed. When the groundspeed (and airspeed) reach 120mph, the wheels and tires will be spinning at the "treadmillspeed" of 240mph.

Note that F1 cars (and the [url= http://"http://www.dailymotion.com/video/x157l2_bugatti-veyron-at-top-speed"]Bugatti Veyron[/url]) can drive that fast, and the biggest problem these cars have at high speeds isn't wheel/tire friction, it's air friction (aka "drag"). Therefore, certainly there is not enough rolling resistance in the tires against the treadmill surface to provide much (if any) hindrance to an aircraft's engine. Nor is there substantial friction in the wheel bearings, which likely can spin at even higher speeds.

However, I did a little googling to find out what the speed rating is for aircraft tires, and I discovered that most of them are NOT rated for twice the take-off speed of the aircraft they're designed to be mounted on. Most seem to be about 50%-80% higher than the take-off speed of the aircraft.

So, if an aircraft on a treadmill cannot achieve its take-off speed before a tire fails, it will most definitely NOT take off, and will instead look a lot like [url= http://"http://www.metacafe.com/watch/407616/richard_hammonds_crash/"]this dragster piloted by Richard Hammond[/url]. But if by chance the tire does not explode before the plane achieves take-off speed, then it will fly.

It's apples and oranges to compare cars and planes in this scenario. With a car, the engine drives the WHEELS which are attempting to drive the car forward against the treadmill. With a plane, the engine drives the AIR which in turn pulls (propeller) or pushes (jet engine) the plane through the air while the wheels are spinning freely against the conveyor belt, however fast it chooses to go.

Therefore, it doesn't matter one iota how fast the conveyor is spinning, accelerating, or slowing down... the wheels are not in "gear," they spin freely, so even though they might be spinning at a zillion rpm, the plane's forward momentum is still governed by the thrust of the engine.

Hell, a 747 has enough engine thrust to take off even if its wheels were to fall off...

Why is this so hard for people to get? It's like being at the drag strip and hearing the ignorant masses let out their "BOOOOs" when the jet car fails to do a "burnout." It CAN'T for the same reason that the treadmill is immaterial...

If a regular xterra and an xterra with a jet engine on its roof, each with slick tires, were sitting side by side on an infinite sheet of glare ice; the regular x would sit and spin while the jet x would shoot across the ice like a lightning bolt. Does that help?

A harrier & ospray can take off with zero air speed & zero ground speed.

So a plane can take off regardless of any treadmill matching its speed. Myth busted!!!

Now about this already

Y'all are "faking stoopid", aren't ya?

Tryin' to get someone to bite, and get another flamefest pushing 100 pages again.



(Must not bite . . . must not bite . . . must not bite . . . )

Hammond's dragster didn't have wings.

. . . goddammit all to hell, I bit.

Fuck.

How could you get caught up in this thread? Fool...

Let's not start this again. Fuck, it's been proven already.

Asked and answered.

I wish they would have measured take off distance to see if it was effected.

Funny

It would have been another way to prove that it didn't matter. The test was not for the distance to take off though. It just would have been nice if they did a measurement to see if there was any difference since the truck and the plane speed weren't the same throughout. Better yet, it would have been nice if they ran a second test dragging the tarp at a higher take off speed. I'm all about wanting to see all of the angles though no matter if I know I'm right or wrong.

It's a good thing planes don't get their forward thrust with their wheels.
Otherwise they'd all crash when they retract their landing gear.... :rolleyes:

Some people just have to prove they are as dumb as we think they are, don't they.

Never have I said the plane gets thrust from wheels. I said the tires would blow.

And while a 747 can produce enough thrust to take off with no wheels it would not happen.

And this is why the debate continues.

Someone on a local 4x4 board asked a related question: Could a helicopter take off from a turntable rotating at the same RPM as the blades but in the opposite direction?

I say, discounting the tail rotor, the answer is no. The blades would be stationary in relation to the ground, therefore not moving through the air to create lift. The net effect would be the same as if you held the blades and spun up the turbine: the copter would spin under the blades.

The helicopter wouldn't be able to stay on a turntable that moved as fast as the blades. It would be thrown off, so in essence it is a moot point.

But, if it could stay on a turntable moving at such a rapid velocity, yes, it probably would be able to take off.

Paul, you're right if it were a plane that required a high enough takeoff speed the tires would explode and the plane would be destroyed. But the myth says "a plane" not every plane

Actually the debate does not continue. Dumbasses like you continue to embarass themselves.


This has always been a High School Physics I question. Sorry if you missed the class.

Hahaha! You clearly did not read my full post, instead inserting "blah blah" where you chose to ignore the point I was trying to make. :rolleyes:

Explain how I am embarassing myself? Really do you even read my posts? Someone has already agreed with me that is on your side. So piss off geek

Thank you. All I suspected was my theory was possible on a bigger plane. I will hush now as oto not offend Jeffsucksdicks

You don't offend me. You make me laugh. Even large plane wheels are unlikely to explode. The reason is that the wheels/tires are rated well over operational requirements. They can easily survive extreme cicumstances such as double speed because of a factor of safety is built in.

At the end of the day none of that matters. The question is a Physics I problem. Speculation about the wheels or tires is just a distraction introduced by those too ignorant to understand the fundamentals of this simple question.

Interesting...tht got me thinking if the turntable was spinning but the rotor isn't, would the Hellicopter lift off of the turntable if it matched the rpms of the rotor at takeoff?

Great, now we have something else for Mythbusters to test, and have people still argue over anyways. :rolleyes:

Probably, but as soon as it left the turntable, it would come back down, since the turntable (external to the helicopter) was the source of power.

Jeff you are a complete idiot you have now proven yourself. Aircraft tires while designed to be tougher than regular tires are still rated for speed. It amazes me you think the tires can handle double the speed they are rated for. I in my theory of why a large plane would not fly on this myth even gave the tires to well over four times what they were rated at before failing. Here is a link for military and large aircraft tires. Note the speed rating. The tires are built strong for the shock of landing. Not to drive 500 miles per hour.

Jeff is a fucking arrogant asshole

I understand the plane will move. I understand the physics as to why the plane will move. I have never ever debated that. I simply posted another theory to the original question in which a large plane requiring a longer acceleration and how I felt it would fail. Never said it wouldn't move. Just said it would not take off. The tires would fail and no matter how powerful the engines were if the tires failed soon the landing gear would and the plane would not take of due to that or running out of runway. it is that simple I am not making it complicated or trying to hold on to the plane not flying. You are too hell bent on being some kind of god in your own eyes who gets off on calling people idiots to probably understand. It is ok. They make medicine for your condition. It is called go fuck yourself. it can be found at Walgreens for 19.95.

"They make medicine for your condition. It is called go fuck yourself."

Classic. Noted for future use.

Just a thought, Paul, because you are hung up on the wheels failing -

In the original scenario the plane (of no specific type) is sitting on a treadmill of infinite length.

So why are you hung up on the practical problem of the tire rating but choose to totally ignore the pratical problem that the treadmill in the scenario can never exist, because the belt for the treadmill would have to be twice the length of the treadmill, and since 2x infinity can only equal infinity if 2 is equal to 1 (which it isn't) the treadmill in the scenario will never really exist.

If you want to nitpick, why don't you assume the plane is a wooden antique which has been exposed to the elements and termites and which, because fo the structural damage from time and exposure, preceeds to fall apart from the engine vibrations?

Yes, in the real world, the tires might fail before the plane takes flight, but that's really not the essense of the myth.

Oh I agree that the treadmill would never exist. Just was thinking out loud to myself about the myth when in the 70 page thread and posed my theory. If it was possible to make that treadmill and possible to give it as much power as I could fathom then my theory works out. Then Jeff pissed me off with his I am a god hear me roar this is physics I am smarter than you etc etc when I was not even really debating the original myth. So I decided to dive into it a bit for a bit more fun.

I am not really hung up on the wheels in the original myth. Maybe again if I had unlimited power to ramp that treadmill up to 10,000 miles per hour to try and make the wheels fail because I agree it wouldn't make the plane stop moving in the original or my side thoery it may make even a smaller plane's wheels fail but again not possible to even do that.

Alright enough fun

Man you guys need to get a hobby...

XOC is my hobby lol

What if we put a hobby on a treadmill...?

Then it would probably take the fuck off if it had a Propeller or Jet Engine strapped to it.

Why don't you just disassemble the conveyor belt and turn it into a giant winch. That would keep the plane from taking off for sure (assuming the conveyor belt / winch is properly anchored with pylons driven into bedrock).

Yes, but if that helicopter had wheels like an office chair...

Holyshit. Another excuse to use this? I cant believe it!


BUSTED!!!!!!!!!!!!!!!

Maybe we need to use the BULLSHITDYNO too?? (hinthint)


MGJ

20 bucks, huh? Sounds like a ripoff.

I think the reason we're not agreeing is because we are thinking of different types of planes. This is my plane:

Jeff, you have a reading comprehension problem. Or maybe it's just you being an ass and pushing buttons for the fun of it...I don't know or care, but...READ CAREFULLY WHAT I HAVE WRITTEN BELOW.

In the confines of the riddle, the plane flies.

Using a real world plane, with a fictitious conveyor belt runway, the tires blow, the plane doesn't fly.

Did you even watch the mythbusters episode? Some planes may have tire issues, but others can undoubtedly take off (on a simulated treadmill). I don't understand why this is still a debate.

I suggest you go re-read my comments before commenting. I'm trying to explain to Jeff what Paul's comments are. All of the above are in reference to a full size jetliner.

Thanks for playing .