Poll: Mythbusters - Will the plane take off?

Berkut said:
It was just hypothetical. No one was saying that an aircraft on a treadmill actually provided any benefit. I replied to you back on page one and said:
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Ok, I get it now. I thought there was actually a purpose of this airplane/treadmill scenario. I thought people were trying to argue that if the treadmill moved backwards at the aircrafts takeoff speed, that the aircraft could take off without moving relative to the ground... thus allowing you to takeoff with almost 0 runway.

The way I understand this question now is, if a treadmill is moving backwards, can an airplane still take off? Of course it can. The wheels may be spinning at twice the speed, but the airplane is still moving forward at its takeoff speed (relative to the ground). So there is no benefit to the airplane/treadmill scenario.

Problem solved. This does not need debating. The answer is obvious. The question is just a very poor one.



Clocks, I know you went to ATP, but the moving forward at 60kts
(-60 + 60 = 0) comment means moving 60kts RELATIVE to the treadmill (which is moving backwards at 60kts). Thus the speed RELATIVE to the ground is 0kts. That is still correct. Maybe I did not make it clear what the reference frame was. After all, the airplane is moving 67,000mph RELATIVE to the sun. My mistake for not clearly stating my coordinate frame, but the comment is still correct.
 
aerospacepilot said:
I understand. But lets say you were standing on non-moving ground right next to the treadmill. How fast does the airplane appear to be moving RELATIVE TO YOU (standing still). If it is 55kts, then this scenario is stupid. It has no purpose.
Am I correct?
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Wow man. Are you NOT reading the replies that Professional pilots have given you? You get one pardon, but thats it. You clearly are misunderstanding the concept and the physics about this, therefore your CFI= Suck! (if you have a CFI)

The wheels of the airplane, have NOTHING to do with the PHYSICS of the aircraft flying. OK, they might have a bit of DRAG in the form of friction with the surface on the ground roll, but thats it. As long as the wheels can tolerate the high speed, it doesn't matter how fast the treadmill goes. Once the aircraft engine produces THRUST (you know, in the form of propeller wash or jet exhaust), it will accelerate. It nots like a car which is gear driven and uses the ground to propel it forward via the torque generate from the engine and gearbox.

This is simple mechanical and physical science here, I don't understand how people don't get it. And no, I didn't go to college.

The critical point of the experiment, is that the treadmill must be equal to or longer then the ground roll of the aircraft on take off. If it isn't, then the airplane just goes off the end (like they showed on the inital test).
 
I think perhaps another reason why we are having a misunderstanding is that you guys are assuming that when the treadmill starts rolling, that the airplanes wheels will roll, but the airplane is staying still.

I am assuming that the treadmill will not accelerate fast enough to break the static friction between the wheels and the treadmill. ie. Imagine you put a shoe on a treadmill, then turned it on... The shoe would move backwards at the speed of the treadmill.
 
aerospacepilot said:
I think perhaps another reason why we are having a misunderstanding is that you guys are assuming that when the treadmill starts rolling, that the airplanes wheels will roll, but the airplane is staying still.

I am assuming that the treadmill will not accelerate fast enough to break the static friction between the wheels and the treadmill. ie. Imagine you put a shoe on a treadmill, then turned it on... The shoe would move backwards at the speed of the treadmill.
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Ok, now I can't help you any more.:banghead:
 
I am not ashamed to show up. I voted NO because I misunderstood the question. The way I understand the question now (and I assume this is the way the question was originally meant), the answer is obviously YES.

I am trying to explain why I was confused with the question. And I am trying to tell clocks that he needs to understand what reference frame I am talking about before he makes a wrong statement.
 
aerospacepilot said:
I think perhaps another reason why we are having a misunderstanding is that you guys are assuming that when the treadmill starts rolling, that the airplanes wheels will roll, but the airplane is staying still.

I am assuming that the treadmill will not accelerate fast enough to break the static friction between the wheels and the treadmill. ie. Imagine you put a shoe on a treadmill, then turned it on... The shoe would move backwards at the speed of the treadmill.
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Really? Thats 3rd grade stuff there man. Thats why to make the experiment work, and the real conditions of the myth are - that the airplane increases thrust to take off power at the exact same moment the treadmill or conveyor belt starts.

Ah...I give up.
 
I voted no also, but I didnt read the question correctly either. As soon as I saw them putting the experiment together it clicked...I suck, oh well.
 
Berkut said:
Indeed.

Do any of the "no" voters want to tell us what they did wrong that allowed the aircraft to take off?
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I voted no because I misunderstood the experiment. I thought the engine wasn't on and the plane was staying in one spot as the wheels were moving.

I realize the error of my thinking, and in no way, shape, or form will I argue against the results.
 
aerospacepilot said:
I think perhaps another reason why we are having a misunderstanding is that you guys are assuming that when the treadmill starts rolling, that the airplanes wheels will roll, but the airplane is staying still.

I am assuming that the treadmill will not accelerate fast enough to break the static friction between the wheels and the treadmill. ie. Imagine you put a shoe on a treadmill, then turned it on... The shoe would move backwards at the speed of the treadmill.
Click to expand...

This is the point where I give up. :banghead:
 
juxtapilot said:
I can't believe the pilot didn't think the airplane would take off!!!
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Dude, there are numerous pilots here on JC that didn't think it would take off. Not just in this thread, either. ;)
http://forums.jetcareers.com/general-topics/34216-can-the-plane-fly-if.html
http://forums.jetcareers.com/general-topics/22291-airplane-riddle-taken-from-another-board.html
http://forums.jetcareers.com/general-topics/38345-stupid-plane-on-a-treadmill-question.html
http://forums.jetcareers.com/general-topics/56281-can-an-airplane-take-off-on-a-treadmill.html
http://forums.jetcareers.com/general-topics/54120-mythbusters-to-take-on-plane-on-a-treadmill.html
http://forums.jetcareers.com/genera...-mythbusters-plane-on-a-treadmill-thread.html

So, the fact that the experiment pilot didn't think he would be able to take off doesn't surprise me. Also, the initial reaction of almost everyone I've discussed this riddle with, including pilots, is NO (until I make them see the light :D).

Edit: Forgot to add, DO NOT POST to any of the threads I linked above if they aren't already locked!!! The Wrath of Amber will be visited upon you! ;)
 
I can understand when people give their gut reaction that it won't take off the first time they hear the riddle. What I don't understand are the people that continue to argue after you've explained it to them.
 
firebirdswm said:
:yup:

Exactly what I was trying to figure out! I can't tell what side of the argument he's on anymore. I'm not sure he knows.
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I was disputing the notion of the (lack of) interaction of the plane with the ground, which, now that I got it, is irrelevant.

They just needed to get 20 kts worth of air moving over the wings in relation to the stationary airmass, regardless of how fast the "ground" was moving.

I got it, I got it...
 
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