[ 3 / biz / cgl / ck / diy / fa / ic / jp / lit / sci / vr / vt ] [ index / top / reports ] [ become a patron ] [ status ]

2023-11: Warosu is now out of extended maintenance.

/diy/ - Do It Yourself

File: 10 KB, 251x251, threadmill.jpg [View same] [iqdb] [saucenao] [google]

190482

None Wed Apr 4 03:21:03 2012 No.190482 [Reply] [Original]

I think we all remember the massive amounts of speculation that went on surrounding this image and I think that we all also remember that this debate was "settled in the lab" by mythbusters, who flew a piper cub off of a treadmill.
For people who are familiar with how airplanes actually work (as opposed to the average cable TV viewing couch potato), you probably realize that the way a STOL piston prop like a cub attains flight is very, very different from a 767 heavy jetliner. People familiar with small prop planes, especially people who have seen stuff like "long props and big rocks" will recognize that under the right wind conditions, a cub can take off and land pretty much like a chopper. The rest of you all know that an airplane attains lift by the suction created when air moves over the wings and that the cub's prop's slipstream moves a massive amount of air over the cub's wings at very high speed, something that a jet aircraft does not do.
i don't want to be any more longwinded and boring than i've already been, but the tl;dr version of this is that i don't think mythbuster's flying a cub off of a treadmill had to much at all to do with the question in this now-famous image, a cub is practically as different from a jetlliner as a robinson-44 is.
Mythbusters answer didn't respond to the question asked in pic related.
What do you think about it?

>>

Anonymous Wed Apr 4 03:45:50 2012 No.190495

I think you raise a valid point, but we have to remember that mythbusters is a tv show with a finite budget and bringing in a 767 is way beyond cost prohibitive. Not to mention the logistics of building a treadmill large enough to place a fuck huge jetliner on. What I would have like to have seen is them trying to take off in the plane from a stationary position sans treadmill. This would have defeated any doubt that the moving track had anything to do with it. Also, this may be better in /sci/, there isn't really anything particularly DIY about this topic, interesting as it may be.

>>

teka Wed Apr 4 04:42:30 2012 No.190528

>For people who are familiar with how airplanes actually work (as opposed to the average cable TV viewing couch potato), you probably realize that the way a STOL piston prop like a cub attains flight is very, very different from a 767 heavy jetliner.

I just have to take a second and stop you there.

No. That is wrong.
They both fly for exactly the same reason. Air moving over the wings to create lift. Almost always this means the plane is thrusting forward with a prop or jets, moving through the air and lifting. In the case of some extra-small, extra-light planes a gust of wind moving over the wings is enough to create the same effect.

Since a plane does not "drive" up to speed with it's wheels it does not much matter what is happening down there. A treadmill going the wrong way is just a tiny amount of drag on the effectively free-spinning wheels.

Perhaps some wheel speedometer reads an extra-high speed as the plane accelerates with thrust as normal, reaches it's normal take-off speed relative to the air, and lifts off.

In the show they showed that "A Plane" will take off from "A Treadmill". A toy plane will take off from a small treadmill, a smallish but very real plane will take off from a comically oversize treadmill.

I think your pasta is stale, and anyone who repeats the claims it makes is foolish.

>>

Anonymous Wed Apr 4 09:03:18 2012 No.190615

hahahahaha
hahahahahahhaahah
aaahahahahahahahahah
oh wow
oh wait....
if the treadmill was moving fast enough that the friction between air and treadmill surface managed to move enough air at the height of the wings that it was equivalent to takeoff speed of the aircraft ..then sure, it would take off... until it got a little way into the air and the air movement caused by the treadmill dropped off.. then t would fall again.
But the landing gear would have melted before that anyway.
What a fucking stupid scenario this is.

>>	WillyTheDisk !!W4ldCS0N1db Wed Apr 4 16:41:13 2012 No.190865 >>190615 What is this I don't even

>>	WillyTheDisk !!W4ldCS0N1db Wed Apr 4 16:57:05 2012 No.190881 >>190615 What is this I don't even

>>

Anonymous Wed Apr 4 16:58:21 2012 No.190882

Of course it would take off, cub, 767, rc plane, learjet, it doesn't matter. Hit the throttle and you're gone. Only uneducated fucks think otherwise.

Pretty sure it wouldn't even require a longer runway to achieve liftoff velocity, but I don't know physics, just simple logic.

>>	Anonymous Wed Apr 4 17:17:37 2012 No.190888 File: 31 KB, 363x310, 1301962144574.jpg [View same] [iqdb] [saucenao] [google] >>190882 Just. No.

>>

sage sage Wed Apr 4 20:06:30 2012 No.191008

>>190888
Actually, Just yes.

Unless you want to go and find an aircraft which has its engine/jet turbine attached through driveshafts etc to the wheels.

Good luck with that one.

incidentally, to get the air moving along above a conveyor belt would take an insane speed (ie, well over supersonic), and even then, its not going to create some magical collumn of air up to the wings. more than a few inches above the surface, it'd be pretty calm.

politely saged.

>>

Anonymous Wed Apr 4 20:14:16 2012 No.191013

What do I think? I think OP is an idiot or a troll.

As a pilot I understand everything you attempted to say. But, lets spell it out. The speed of the ground below the airplane is irrelevant, 747, 767, A380, Cub, 172, F-15, whatever. That is why planes fly using Knots, not MPH. That is why true airspeed, relative airspeed, and ground speed are all separate concepts for pilots.

Taking off with the wind has a far greater effect on take off than a tread mill would.

>>	Anonymous Wed Apr 4 20:45:53 2012 No.191026 The only possible factor that would prevent the plane from taking off is the maximum rated speed of the tires. Spin them too fast and they're likely to explode.

>>	Anonymous Wed Apr 4 21:49:36 2012 No.191058 Flight with the plane is only possible when there is air resistance on the wings, the plane is completely stationary, thus, the plane would not take off. Fairly simple, no?

>>	Anonymous Wed Apr 4 23:17:09 2012 No.191093 Somebody, PLEASE post some illegal image or something so the mods have an excuse to delete this entire cancerous thread!

>>	sage sage Thu Apr 5 02:48:19 2012 No.191214 >>191093 Should already be deleted for not being /diy/ related. This cancer belongs in /b/ or /sci/