- My Forums
- Tiger Rant
- LSU Recruiting
- SEC Rant
- Saints Talk
- Pelicans Talk
- More Sports Board
- Fantasy Sports
- Golf Board
- Soccer Board
- O-T Lounge
- Tech Board
- Home/Garden Board
- Outdoor Board
- Health/Fitness Board
- Movie/TV Board
- Book Board
- Music Board
- Political Talk
- Money Talk
- Fark Board
- Gaming Board
- Travel Board
- Food/Drink Board
- Ticket Exchange
- TD Help Board
Customize My Forums- View All Forums
- Show Left Links
- Topic Sort Options
- Trending Topics
- Recent Topics
- Active Topics
Started By
Message
re: Myth Busters/Can a plane take off on a conveyor belt
Posted on 10/24/07 at 8:55 pm to General
Posted on 10/24/07 at 8:55 pm to General
quote:
With your anology the plane could have cinder-blocks for wheels and still get airborne just as easily but we all know that aint happening.
Nah, cinderblocks for wheels would be enough linkage between the plane and the treadmill to prevent it from taking off.
Posted on 10/24/07 at 8:58 pm to LSUBoo
When do they do the test?
Posted on 10/24/07 at 8:58 pm to LSUBoo
but there free spinning cinder blocks
Posted on 10/24/07 at 8:58 pm to General
quote:
You guys are getting to technical use some fricking common sense.
what the hell does common sense have to do with a plane taking off of a treadmill in the first place? It's a theoretical question.
Posted on 10/24/07 at 8:59 pm to saderade
quote:
When do they do the test?
already maybe... the episode airs in December sometime...Posted on 10/24/07 at 9:01 pm to General
quote:
but there free spinning cinder blocks
where?
Posted on 10/24/07 at 9:04 pm to General
quote:Well, it seems that you're starting to understand the concept of linnkage.
The plane has to overcome more than just the friction of the air. It also has to overcome the friction of the surface its taking off from. It's harder to take off from grass and mud than it is from concrete just like it's harder to drive through grass and mud.
The conveyor belt is flat like the concrete. However, if you want the conveyor belt to be like grass or mud, all you're really doing is adding a smidgeon of linkage.
Thus, under your scenario, the plane has to over the negligible friction of air, and the negligible friction of the grass and mud. Either way, that plane is flying.
This is really getting fun.
Any more questions or responses?
This post was edited on 10/24/07 at 9:06 pm
Posted on 10/24/07 at 9:07 pm to just me
Everybody is getting caught up in the linkage and friction of the wheels and that's not the issue. If the plane isn't moving at all. The treadmill is moving 100kts, the planes wheels are spinning at what would be 100kts. The plane is resting motionless in space but the wheels and tread mill are running full blast. This is the spirit of the myth. If this is the case. The plane is going nowhere, regardless of how high you jack up the speeds. Even if it is a theoretical 10000mph. There is still no air going over the fricking wings and the plane is spinning its wheels really fricking fast on the ground.
Posted on 10/24/07 at 9:08 pm to LSUBoo
Because you guys see a treadmill I see a runway. If the runway is stationary then the plane will move forward if there is enough thrust to overcome friction and drag. While the airplane is sitting stationary on the runway the surface its sitting is moving the same speed as the wheels of the airplane hence zero relative motion. As power is added and motion becomes positive the treadmill is started in the opposite direction of the airplane thus cancelling out the plane's forward motion. No forward motion no airspeed.
Posted on 10/24/07 at 9:08 pm to General
quote:
The plane is sitting on the treadmill so there is friction between the wheels and treadmill surface.
There is friction between the wheels and the treadmill. The friction causes the wheel to move. However, there is a bearing between the wheel and the landing gear's leg. This bearing means that the friction isn't transfered to the plane so the plane won't move.
quote:
With your anology the plane could have cinder-blocks for wheels and still get airborne just as easily but we all know that aint happening.
Cinder-blocks don't rotate well so we can't put bearings on it. We would have to find another way to get rid of the friction. Check out JustMe's plane on ice example above. This is getting off topic though. I'm not trying to be condescending. I'm trying to explain clearly. Sorry if it comes off wrong.
Posted on 10/24/07 at 9:10 pm to penthouse
quote:
The treadmill is moving 100kts, the planes wheels are spinning at what would be 100kts
What ends up happenning, in theory... is that the plane moves forward at 100kts, the treadmill moves backwards at 100kts, and the tires move forward at 200kts. In theory.
Posted on 10/24/07 at 9:11 pm to penthouse
Penthouse that's what I've been trying to say the whole time.
Posted on 10/24/07 at 9:14 pm to LSUBoo
quote:
What ends up happenning, in theory... is that the plane moves forward at 100kts, the treadmill moves backwards at 100kts, and the tires move forward at 200kts. In theory.
No goddammit, thats not the point. The whole point of introducing the treadmill is to keep the plane stationary. For a plane to do that you would need a treadmill the length of the fricking runway which would defeat the whole purpose of the experiment.
Posted on 10/24/07 at 9:16 pm to penthouse
and the plane doesn't measure speed the way a car does by measuring wheel rotation. A plane measures its airspeed using the pitot static system which is a measure of differences in air pressure/flow. i.e. no airspeed, it will read 0 kts on the airspeed indicator. And it sure as frick isn't taking off with the needle pegged at 0.
Posted on 10/24/07 at 9:17 pm to penthouse
quote:
No goddammit, thats not the point.
No, that is the point. Just because the plane is on a treadmill countering its speed, doesn't mean it doesn't move, because the wheels are a 'buffer' of sorts between the plane and the treadmill. The treadmills energy is transferred to the wheels, which do NOT transfer it to the plane in regards to airspeed.
quote:
For a plane to do that you would need a treadmill the length of the fricking runway which would defeat the whole purpose of the experiment.
There's a purpose to this experiment?
Posted on 10/24/07 at 9:20 pm to LSUBoo
well then you could make a treadmill 5000 feet long. Run it at 1mph, have the plane take off at 101 mph and then say,
"ooh, look, we made a plane take off on a treadmill"
but i don't think that's the myth they are trying to bust
"ooh, look, we made a plane take off on a treadmill"
but i don't think that's the myth they are trying to bust
Posted on 10/24/07 at 9:22 pm to penthouse
quote:
but i don't think that's the myth they are trying to bust
No, they're trying to prove that if the plane's airpseed is a theoretical 100kts, and the treadmill is going the opposite direction at that same 100kts, that the plane would, in fact, more forward and take off.
Posted on 10/24/07 at 9:23 pm to LSUBoo
It's gonna be an interesting experiment.
Posted on 10/24/07 at 9:25 pm to LSUBoo
If the plane's airspeed is at 100kts then it will take off but it has to get to 100kts before that can happen.
Posted on 10/24/07 at 9:25 pm to General
quote:
It's gonna be an interesting experiment.
Agreed... I still don't think they'll be able to pull it off... I guess with a long enough treadmill and light enough plane (slow enough take-off speed) they can make it work. No way they could do it full-scale with a 737 or anything like that. Just unfeasible in reality.
Page 4 of 29
Back to top
Follow TigerDroppings for LSU Football News