Mythbusters tackles the plane/treadmill

[87we410877]

You do realize this little comparison has absolutely nothing to do with the fact that a plane is not wheel driven, right? Strap a rocket to the back of your guy running on the treadmill and watch how fast that glider takes off.

He wont take off. He needs rolor blades too. hahah. Had ya pissed for a second there didnt i? hahah. Your right about that.

 

[Pitbozz]

lol. Yea there all clear. I think the question is a little hazy and tricky. We need lawyers to re-write it.

It will absolutely take off if the plane is not held stationary in relation the the ground. The only resistance the tredmill would have on the aircraft is in the wheel bearings which is almost nothing if you pack them at the aircrafts maintenence manual intervals specified within. haha. And like stated above, the wheels will just be going twice as fast.

If its held stationary, its not taking off. The above long post i think clears up some confusion. Its a somewhat tricky question thats counter-intuitive.

Based on the above will determine where my cars go. If the plane moves yes if not no.

There is absolutely no reason the plane WON'T move. So send me the worst of your GN's and we'll call it even.

Sorry ALXTTA 1.

 

[87we410877]

There is absolutely no reason the plane WON'T move. So send me the worst of your GN's and we'll call it even.

Sorry ALXTTA 1.

LMAO. It'll be about 300 boxes. Its in the middle of a frame off.

Re-reding the question, it will take off no doubt in my mind. I'll put the remaining two GNs on that. lmao. this is fun. :biggrin:

 

[Pitbozz]

LMAO. It'll be about 300 boxes. Its in the middle of a frame off.

Re-reding the question, it will take off no doubt in my mind. I'll put the remaining two GNs on that. lmao. this is fun. :biggrin:

Allright...that's one GN.

I still owe ALXTTA 1 a great deal on a GN.

Anyone else feel like betting?

 

[ALXTTA 1]

If you find one, I'll trade ya straight up for a slightly used treadmill.

Allright...that's one GN.

I still owe ALXTTA 1 a great deal on a GN.

Anyone else feel like betting?

 

[Pitbozz]

If you find one, I'll trade ya straight up for a slightly used treadmill.

:biggrin: :biggrin: :biggrin:

 

[SouthernCal GN]

Allright...that's one GN.

I still owe ALXTTA 1 a great deal on a GN.

Anyone else feel like betting?

No, just a question- you seems to have all the "googled" answers regarding this, but your answers indicate you don't more than a surface understanding of flight mechanics.

Do you fly or control?

This thread is interesting because of the debate generated. Obviously greater minds than ours have weighed in on both sides of the debate, with a like agreement to disagree. I stated earlier, my logic may be flawed, as the initial question remains vague enough to create doubt.

Then again, I may be correct

My creds- USN Air intercept controller (F-14/FA-18/E-6B) and rotary wing ASW crew/controller.

Good thread. The results will incite more debate....

 

[Pablo]

There is no way the plane is taking off if it remains stationary in relation to the atmosphere. I dont see hoe this can even be debated. its like saying if i hook up a drill motor to an aircraft wheel while its on jacks and fire the engines up, it will take off. If the plane is not moving relevant to the air, or ground (not treadmill) there will be no lift created under the wings. Yes the engines produce thrust to keep it in place but like said above, not over any of the lifting surfaces except maybe the horizontal stabalizer. A prop plane has some thrust over the wings but its negligable compared to whats need for lift.

If it takes off, they have the aircraft moving at take off air speed.

If its stationary its not going anywhere and i'll put all three of my GN's on it. BTW im an aircraft mechanic as well.

What kind of aircraft do you work on, please tell me where the ground speed indicator is on it.

If ground speed meant ANYTHING, it would certainly have a gauge.

There is a reason you have a 6 pack standard cluster on a lot of GA aircraft and NONE of them have ground speed... None of the military aircraft I work on have a ground speed indicator on them either. I am excluding the nav equipment because that is not necessary nor used for flight except but to know where you are going and how far you have traveled.

What the ground is doing under an aircraft has absolutely nothing at all to do with its flight. You can "drift" a plane (yaw relative to the ground) on skis in a crosswind and take off.

I also fly RC planes and it is easy to fly an rc plane "stationary" relative to the ground and sometimes even backwards. The only thing that matters is the relative wind over the airfoil.

The ground means NOTHING.

 

[Pablo]

No, just a question- you seems to have all the "googled" answers regarding this, but your answers indicate you don't more than a surface understanding of flight mechanics.

Do you fly or control?

This thread is interesting because of the debate generated. Obviously greater minds than ours have weighed in on both sides of the debate, with a like agreement to disagree. I stated earlier, my logic may be flawed, as the initial question remains vague enough to create doubt.

Then again, I may be correct

My creds- USN Air intercept controller (F-14/FA-18/E-6B) and rotary wing ASW crew/controller.

Good thread. The results will incite more debate....

Please tell me where the Ground Speed Indicator was in any of those aircraft.

No great mind is necessary. This isn't a question even worthy of great minds.

 

[Pitbozz]

No great mind is necessary. This isn't a question even worthy of great minds.

That a crack on me?!? :biggrin:

 

[corsair231]

What if we turbo charge the motor on the treadmill?

What if we put drag radials on the plane?

How about if we install a transbrake and a 3500 lock-up converter?

What is the price of tea in China?

People this is a car forum. Who cares if it flies, what's the 1/4 e.t.?

What I really want to know is where are they planning to get a conveyor belt from that is as long and as wide as an airstrip?


Actually I theroize that the plane may actually achieve flight sooner. Just look at the viscosity and the shear properties of fluid in movement. I think the moving conveyor will actually pull a stagnant layer of air along with it, increasing the pressure under the wing, in effect increasing the plane's relative air speed, creating lift sooner than normal. Sort of why they put a carrier into the wind for flight ops.

 

[fubar2.5]

I think the bottom line here is if the plane is not moving then neither is the conveyer so the conveyer cannot match the speed of the plane.
If one is not moving then niether is the other.

 

[87we410877]

What kind of aircraft do you work on, please tell me where the ground speed indicator is on it.

If ground speed meant ANYTHING, it would certainly have a gauge.

There is a reason you have a 6 pack standard cluster on a lot of GA aircraft and NONE of them have ground speed... None of the military aircraft I work on have a ground speed indicator on them either. I am excluding the nav equipment because that is not necessary nor used for flight except but to know where you are going and how far you have traveled.

What the ground is doing under an aircraft has absolutely nothing at all to do with its flight. You can "drift" a plane (yaw relative to the ground) on skis in a crosswind and take off.

I also fly RC planes and it is easy to fly an rc plane "stationary" relative to the ground and sometimes even backwards. The only thing that matters is the relative wind over the airfoil.

The ground means NOTHING.

Read on thats exactly what i said.

 

[Pitbozz]

What I really want to know is where are they planning to get a conveyor belt from that is as long and as wide as an airstrip?

From my understanding of it, Mythbusters used an ultralight on a big conveyor belt.

 

[Pitbozz]

What kind of aircraft do you work on, please tell me where the ground speed indicator is on it.

If ground speed meant ANYTHING, it would certainly have a gauge.

There is a reason you have a 6 pack standard cluster on a lot of GA aircraft and NONE of them have ground speed... None of the military aircraft I work on have a ground speed indicator on them either. I am excluding the nav equipment because that is not necessary nor used for flight except but to know where you are going and how far you have traveled.

What the ground is doing under an aircraft has absolutely nothing at all to do with its flight. You can "drift" a plane (yaw relative to the ground) on skis in a crosswind and take off.

I also fly RC planes and it is easy to fly an rc plane "stationary" relative to the ground and sometimes even backwards. The only thing that matters is the relative wind over the airfoil.

The ground means NOTHING.

He's already seen the light.

 

[noslo6]

Please tell me where the Ground Speed Indicator was in any of those aircraft.

No great mind is necessary. This isn't a question even worthy of great minds.

I couldn't agree more Pablo. Credentials ≠ Logic

 

[at7we2]

WTF!

the poll ratio of "yes" versus "no" is actually approaching 50/50. are you guys just playing around or something? I sincerely hope nobody actually *doubts* the plane *WILL* take off!!

you guys who are saying "no, it won't take off" actually have driver's liscenses????

like someone else posted....

THE TREADMILL IS IRRELEVANT!
THE TREADMILL IS IRRELEVANT!
THE TREADMILL IS IRRELEVANT!

The treadmill will *NOT* keep the plane stationary. Turbine engine, propeller, rocket engine....doesn't matter. They all develop thrust against the AIR around the plane, *NOT* against the ground or the treadmill. It would not even matter if the treadmill was moving 500 mph in the opposite direction. The plane would still develop forward velocity in relation to a fixed point in the atmosphere at the same rate. The ONLY limiting factor would be wheel bearing or wheel brake friction. If the brakes are released and the wheel bearings are functioning normally, the plane will move forward as usual. PERIOD! The treadmill will just spin the wheels faster, that is all!

Think about it....when you're flying in an airplane in the opposite direction of the earth's rotation (which is approx. 1,070 mph at the equator!), does it matter that the ground below you is moving that fast in the opposite direction? No, because the planes engines are producing thrust against the AIR not the ground below. The same airplane will have an *airspeed* of 300 mph regardless of what the ground (or treadmill) is doing below! It is that *airspeed* not *groundspeed* that gives the airplane lift.

?comprende'?

 

[jpratt]

The error in the poll is that when people change their minds they cannot change their vote.

 

[noslo6]

WTF!

the poll ratio of "yes" versus "no" is actually approaching 50/50. are you guys just playing around or something? I sincerely hope nobody actually *doubts* the plane *WILL* take off!!

you guys who are saying "no, it won't take off" actually have driver's liscenses????

like someone else posted....

THE TREADMILL IS IRRELEVANT!
THE TREADMILL IS IRRELEVANT!
THE TREADMILL IS IRRELEVANT!

The treadmill will *NOT* keep the plane stationary. Turbine engine, propeller, rocket engine....doesn't matter. They all develop thrust against the AIR around the plane, *NOT* against the ground or the treadmill. It would not even matter if the treadmill was moving 500 mph in the opposite direction. The plane would still develop forward velocity in relation to a fixed point in the atmosphere at the same rate. The ONLY limiting factor would be wheel bearing or wheel brake friction. If the brakes are released and the wheel bearings are functioning normally, the plane will move forward as usual. PERIOD! The treadmill will just spin the wheels faster, that is all!

Think about it....when you're flying in an airplane in the opposite direction of the earth's rotation (which is approx. 1,070 mph at the equator!), does it matter that the ground below you is moving that fast in the opposite direction? No, because the planes engines are producing thrust against the AIR not the ground below. The same airplane will have an *airspeed* of 300 mph regardless of what the ground (or treadmill) is doing below! It is that *airspeed* not *groundspeed* that gives the airplane lift.

?comprende'?

Right on brutha!
I find it hard to believe people actually own and work on turbo buicks that can't comprehend this. I'm from Arkansas and even I understand this :tongue: !

 

[corsair231]

What if when the treadmill is going 500 mph and we stop it suddenly. Will the plane stop or will it catapult off of the end?