Mythbusters/airplane on a treadmill.

[Lowrange2]

Finally! Another person says No fly... that's 2 versus 7 or so.

 

[ZacSquatch]

Dude... my first bet was no fly, go fall down a ditch or sumthin, lol

 

[Lowrange2]

Dude... my first bet was no fly, go fall down a ditch or sumthin, lol

I know... and impetus agrees with you. I spent the last 4 hours trying to pull some moron out of a muddy ditch in a stuck stock Exploder... No dice. I'm tired of falling in ditchs tonight. I'll pass.

 

[rocknxj]

I say all you that believe it will fly, and later find out that it does not, sell your Jeep and buy a Yota. That'll learn ya.

 

[impetus-93xj]

well my dog runs on a tred mill .. does that mean that if he runs fast enough he will take off? haha

 

[Lowrange2]

If he had wings, yes.

 

[Lowrange2]

I say all you that believe it will fly, and later find out that it does not, sell your Jeep and buy a Yota. That'll learn ya.

So are you saying that it will not fly?

 

[impetus-93xj]

not a chance

 

[Captain Ron]

Echo... Echoo... Echoooo...

If you didn't hit the side of your head, you wouldn't hear that anymore.

LowRanger, you threw out a guess, you really don't know if in fact it's right or not, and you can't cite any reasonable source so far to explain why the wheels don't matter.

Ive got a degree and my A&P if that means anything and "techincally" an airplane prop produces lift and yes I know all about Trust, lift, drag, weight. Ive also spent a few hours crewing helicopters so if you want to talk about swash plates, gyroscopic procession or centripical/centrifical force, have at it.

You know about "Trust"? me too.

You did not start out talking about "precession", etc... Has nothing really to do with what you did start out with.

Although, if you wanna play really smart guy, you'd have followed up on one particular aircraft type you just used, to use a basic, correct, explanation of what will happen on the treadmill.

--ron

 

[Lowrange2]

LowRanger, you threw out a guess, you really don't know if in fact it's right or not, and you can't cite any reasonable source so far to explain why the wheels don't matter.

As a matter of fact it is comon sense! Why should I need to pull out a reasonable source. Inertia IS the source. An object that is still wants to remain still. An object that is moving WANTS to remain moving! SO, only the small amount of friction in the axle is going to make the plane move because of the conveyor. The wheels are completely irrelevant. I don't understand WHY I have to supply you with a source... It was not a guess. I used what some people call a brain and a lil bit of physics. You, Sir, have no idea what I guessed. I Still have yet to see YOU explain shit! Listing parts of an airplane doesn't contribute anything.

 

[impetus-93xj]

Ive got a degree and my A&P if that means anything and "techincally" an airplane prop produces lift which is the source of thrust and yes I know all about Trust, lift, drag, weight. Ive also spent a few hours crewing helicopters so if you want to talk about swash plates, gyroscopic precession or centripical/centrifical force, have at it.

Well first of all the prop on an airplane does not produce lift it produces thrust causing speed causing air movement around the wings thus causing lift. On a helicopter the prop produces both the thrust and lift .... yes.

 

[impetus-93xj]

So now that we see we have no thrust or lift on said arplain then the only thing remaining is the friction of the tires, axles ect. this will actualy cause the plane to go backwards if not tethered.

 

[Lowrange2]

This is why I wasn't on the debate team. My blood pressure is thru the roof and I would end up killing somone. Well, that and I suck at explaining things. Tho I did finish top of my physics class. The f-ing plane flies! Damn!

 

[Ray H]

If you didn't hit the side of your head, you wouldn't hear that anymore.

LowRanger, you threw out a guess, you really don't know if in fact it's right or not, and you can't cite any reasonable source so far to explain why the wheels don't matter.



You know about "Trust"? me too.

You did not start out talking about "precession", etc... Has nothing really to do with what you did start out with.

Although, if you wanna play really smart guy, you'd have followed up on one particular aircraft type you just used, to use a basic, correct, explanation of what will happen on the treadmill.

--ron

You are correct, I mispelled "precession". Its been a number of years (around 14) since Ive dealt with aerodynamics but im pretty sure the principals havent changed.
Real basic explanation: The plane will fly because the prop will produce thrust which will increase the planes airspeed, eventually creating enough lift to overcome weight. Notice, I didnt mention anything about the treadmill because it doesnt matter.
Im sure you have plenty to add so go ahead.

 

[Lowrange2]

I suck at explaining and this guys explanation is decent so here.

"But of course cars and planes don't work the same way. A car's wheels are its means of propulsion--they push the road backwards (relatively speaking), and the car moves forward. In contrast, a plane's wheels aren't motorized; their purpose is to reduce friction during takeoff (and add it, by braking, when landing). What gets a plane moving are its propellers or jet turbines, which shove the air backward and thereby impel the plane forward. What the wheels, conveyor belt, etc, are up to is largely irrelevant. Let me repeat: Once the pilot fires up the engines, the plane moves forward at pretty much the usual speed relative to the ground--and more importantly the air--regardless of how fast the conveyor belt is moving backward. This generates lift on the wings, and the plane takes off. All the conveyor belt does is, as you correctly conclude, make the plane's wheels spin madly."

and of course the one thing that could lower my blood pressure , "Friend of the day", sucks right now!

 

[Ray H]

Well first of all the prop on an airplane does not produce lift it produces thrust causing speed causing air movement around the wings thus causing lift. On a helicopter the prop produces both the thrust and lift .... yes.

Technically a prop is an airfoil, exactly like a wing or rotor. As it rotates through the air, it produces lift (high pressure on the backside, low pressure on the front). Its this lift the prop produces that becomes thrust.

 

[impetus-93xj]

and the I's have it haha

 

[Skwerly]

This all depends, is the airplane red?

 

[Captain Ron]

...
Real basic explanation: The plane will fly because the prop will produce thrust which will increase the planes airspeed, eventually creating enough lift to overcome weight. Notice, I didnt mention anything about the treadmill because it doesnt matter.
Im sure you have plenty to add so go ahead.

You are close enough. It's a simple explanation, but until now, everyone just threw out wild assed guesses.

To wit: the prop does not technically "produce" thrust. It's one of the basic LowRanger style, seems like common sense principals that is incorrect. The engine produces thrust. If you look at it any other way, too many other basic flight concepts will not work.

For example. Thrust must be equal to drag, and is required for stable state flight to be possible. Gliders are capabile of stable state flight, but they do not have propellers. Where's the thrust?

Helicopters. The Lift/Weight, Thrust/Drag in this configuration to visualize are what the original CFI ended up using to illustrate the relationships, and eventually provide the basis for the whole treadmill thing.

See "Power plus pitch equals performance. Also reference the Power Curve.

This whole thing got started, like I said, along time ago on the AOPA boards and spread to just about all the aviation boards. Amazing how many people passed their oral and written tests. But the stuff I read here took it to a whole new level.

Oh, and BTW Ray. You know that anyone that flies in an airplane where the wings move faster than the airplane have a limited lifespan?

--ron

 

[Captain Ron]

I suck at explaining and this guys explanation is decent so here.

"But of course cars and planes don't work the same way. A car's wheels are its means of propulsion--they push the road backwards (relatively speaking), and the car moves forward. In contrast, a plane's wheels aren't motorized; their purpose is to reduce friction during takeoff (and add it, by braking, when landing). What gets a plane moving are its propellers or jet turbines, which shove the air backward and thereby impel the plane forward. What the wheels, conveyor belt, etc, are up to is largely irrelevant. Let me repeat: Once the pilot fires up the engines, the plane moves forward at pretty much the usual speed relative to the ground--and more importantly the air--regardless of how fast the conveyor belt is moving backward. This generates lift on the wings, and the plane takes off. All the conveyor belt does is, as you correctly conclude, make the plane's wheels spin madly."

and of course the one thing that could lower my blood pressure , "Friend of the day", sucks right now!

Good God dude. While you might be correct in that the plane will fly, how you get there is out to lunch. If you can't post correct information, why not stick to "How much Lift?" type stuff.



--ron