who here really thinks a plane can take off from a treadmill - Page 2

*JackThe Ripper* · 01-31-2008, 05:53 PM

i guess that is what makes it such a damn good question

the way mythbusters did it, of course it would take off.

the way a lot of people, myself included interperated it, it could never take off.

CCM · 01-31-2008, 06:18 PM

How did they do it on mythbusters? Air has to be traveling across the wings at a speed of about 100MPH (?) for it to lift, and then if there's no forward propulsion once it gets airborne, it will immediately fall back to the ground.

PColav6 · 01-31-2008, 06:47 PM

I think they had a truck with a looooooooooong piece of material behind it, with an ultra light weight plane on the material facing backwards, the truck went forwards and the plane took off like that, but unlike the internet debate - the plane was moving, it was not stationary like it would be on a treadmill.

*4.6 Love* · 01-31-2008, 06:48 PM

Damnit...missed it...anybody have a vid of how it was done?

Codiddy · 01-31-2008, 09:15 PM

Quote:

Originally Posted by 4.6 Love

Damnit...missed it...anybody have a vid of how it was done?

http://youtube.com/watch?v=MuXK1nr9_jg
http://youtube.com/watch?v=U9STo3fjfGg
I think there are some other ones just look up mythbusters

CCM · 01-31-2008, 11:25 PM

Quote:

Originally Posted by PColav6

I think they had a truck with a looooooooooong piece of material behind it, with an ultra light weight plane on the material facing backwards, the truck went forwards and the plane took off like that, but unlike the internet debate - the plane was moving, it was not stationary like it would be on a treadmill.

The only way that would work is if it took off in the same direction that the truck was moving. Planes have to take off into the wind.

Dave04Mustang · 01-31-2008, 11:47 PM

on mythbusters they put down a long tarp and then the plane was a small perpeller plain.. the otheriside of the the tarp was attached to a pickup truck and both went a speed of 25MPH and the place kept moving a regular distance because the propeller moved the plane not the wheels. So the plane took off like normal. If anything doesn't make sense its because i just got back and im slightly drunk

PColav6 · 02-01-2008, 07:54 AM

Quote:

Originally Posted by CCM

The only way that would work is if it took off in the same direction that the truck was moving. Planes have to take off into the wind.

No, because the speed of the plane eventually overpowered the truck (which wasn't going fast at all) so it had all of the wind it needed.

*JackThe Ripper* · 02-01-2008, 01:44 PM

yah i gotta say that once you see it happen, it is pretty obvious, the question doesent define many parameters

I always assumed that the question was weather or not it would take off with a treadmill movingin the opposite direction, i never though about the plane itself moving forward, probably due to the nature of a treadmill.

A car in that scenario will not move forward because the propulsion comes from the wheels pushing against the ground, and if the ground is moving backwards, well, the car wont actually move forwards

the plane on the other hand uses propulsion but pulling itself against air, the treadmill may be moving, but the air isnt, so when the plane starts up it WILL move forward by pulling itself ahead with its propeller. The treadmill moves 40mph one direction, the plane 40mph the other direction, but the wheel speed is 80mph.

for some reason, i had limited myself to thinking that the treadmill was moving, and the wheels were moving, but the plane was not moving.

Codiddy · 02-01-2008, 05:36 PM

Quote:

Originally Posted by JackThe Ripper

yah i gotta say that once you see it happen, it is pretty obvious, the question doesent define many parameters

I always assumed that the question was weather or not it would take off with a treadmill movingin the opposite direction, i never though about the plane itself moving forward, probably due to the nature of a treadmill.

A car in that scenario will not move forward because the propulsion comes from the wheels pushing against the ground, and if the ground is moving backwards, well, the car wont actually move forwards

the plane on the other hand uses propulsion but pulling itself against air, the treadmill may be moving, but the air isnt, so when the plane starts up it WILL move forward by pulling itself ahead with its propeller. The treadmill moves 40mph one direction, the plane 40mph the other direction, but the wheel speed is 80mph.

for some reason, i had limited myself to thinking that the treadmill was moving, and the wheels were moving, but the plane was not moving.

that's the key. everybody thinks of it like the plane is a car. but the wheels on a plane just hang out and roll freely, the engines generate thrust against the air behind the plane, which isn't affected by the treadmill.

StreetRacer · 02-01-2008, 05:40 PM

i cant comment...i'm still trying to walk and chew gum at the same time

*JackThe Ripper* · 02-01-2008, 05:58 PM

Quote:

Originally Posted by Codiddy

that's the key. everybody thinks of it like the plane is a car. but the wheels on a plane just hang out and roll freely, the engines generate thrust against the air behind the plane, which isn't affected by the treadmill.

lol... i know damn good and well the wheels just turn, but i guess i was assuming the plane would be remaining in the same place as a parameter to the question, as if they were asking if the plane sitting on a treadmill would just lift up in the air

Codiddy · 02-01-2008, 07:18 PM

Quote:

Originally Posted by JackThe Ripper

lol... i know damn good and well the wheels just turn, but i guess i was assuming the plane would be remaining in the same place as a parameter to the question, as if they were asking if the plane sitting on a treadmill would just lift up in the air

Well I wasn't talking about you specifically. Even I didn't really think the plane would take off but sure enough it did

*JackThe Ripper* · 02-01-2008, 07:20 PM

Quote:

Originally Posted by Codiddy

Well I wasn't talking about you specifically. Even I didn't really think the plane would take off but sure enough it did

Well you should be, lol, after all i was on here all barking out how stupid someone would have to be to think it was possible!

BannyB785 · 06-05-2008, 08:58 PM

Quote:

Originally Posted by foncarelli

I remember when DannyB asked this question.

bullshit I never asked that question

*JackThe Ripper* · 06-05-2008, 09:02 PM

Hey look what the cat dragged in! How's it going?

Nofire · 06-06-2008, 11:53 AM

Whoa, speak of the devil! Where have you been?

BannyB785 · 06-06-2008, 12:23 PM

around. dude, I cant post a f-in thread. It keeps saying "connection reset"

Badfish · 06-06-2008, 12:34 PM

Quote:

Originally Posted by BannyB785

around. dude, I cant post a f-in thread. It keeps saying "connection reset"

your wing is causing too much interference man.

DaGonz · 06-07-2008, 01:27 PM

Quote:

Originally Posted by JackThe Ripper

Ok

lets assume the plane needs to be moving at a velocity of 65mph to achieve enough lift to fly.

Which happens to be the speed at which a Cessna 172 Skyhawk achieves enough lift to get it airborne...

Another thing to throw into the equation is temperature and humidity. Cold dense air will make an aircraft lift off far faster and in a shorter distance than hot, humid air...

r3dn3ck · 06-07-2008, 01:50 PM

can't we just let this damned thread die...

Codiddy · 06-07-2008, 06:53 PM

Quote:

Originally Posted by r3dn3ck

can't we just let this damned thread die...

01-31-2008, 06:18 PM	#32 (permalink)
CCM Senior Member Join Date: Dec 2005 Location: Northern Virginia Posts: 1,382	How did they do it on mythbusters? Air has to be traveling across the wings at a speed of about 100MPH (?) for it to lift, and then if there's no forward propulsion once it gets airborne, it will immediately fall back to the ground. __________________ 2001 MINERAL GRAY GT (5-speed) H&R SuperSports MM 4-Bolt CC Plates Stoptech SS Brake Lines '03 Cobra Brakes Spec Billet Steel Flywheel Spec Stage 2 Clutch FRPP 4.10s X-Calibrator 2 Full Length Subframes Corbeau Legacy Racing Seats 18" Gunmetal Saleen Rims w/ Nitto 555s

01-31-2008, 06:47 PM	#33 (permalink)
PColav6 Saving for new car. lol Join Date: May 2006 Location: Pensacola, Florida Posts: 4,526	I think they had a truck with a looooooooooong piece of material behind it, with an ultra light weight plane on the material facing backwards, the truck went forwards and the plane took off like that, but unlike the internet debate - the plane was moving, it was not stationary like it would be on a treadmill. __________________

01-31-2008, 06:48 PM	#34 (permalink)
4.6 Love Super Moderator Join Date: Sep 2004 Location: Mexico Posts: 6,153	Damnit...missed it...anybody have a vid of how it was done? __________________ Go Cowboys! X pipe and flows

06-06-2008, 11:53 AM	#47 (permalink)
Nofire Sooner #65 Join Date: Dec 2004 Location: University of Oklahoma Posts: 692	Whoa, speak of the devil! Where have you been? __________________ 2004 Mach 1----Black--------Sold. 285HP, 304TQ I WANT MORE!!!

06-06-2008, 12:23 PM	#48 (permalink)
BannyB785 Junior Member Join Date: Sep 2005 Posts: 17	around. dude, I cant post a f-in thread. It keeps saying "connection reset" __________________ Last edited by BannyB785 : 06-06-2008 at 12:32 PM.

02-01-2008, 05:40 PM	#41 (permalink)
StreetRacer Banned Join Date: May 2007 Posts: 1,639	i cant comment...i'm still trying to walk and chew gum at the same time

06-07-2008, 01:50 PM	#51 (permalink)
r3dn3ck Wowbagger hates me too! Join Date: Nov 2005 Location: Magrathea/California Posts: 7,006	can't we just let this damned thread die... __________________ Built 5.5L 2v and Maximum Motorsports Max Grip box. www.squarerootofone.com My CarDomain Page