Does the plane REALLY take off? It depends.

[Captante]

At no point have I argued that the wings don't provide lift!
Engines push against air, this moves aeroplane forward, forward motion moves air over wing, wing provides lift.
The treadmill isn't going to stop any of that!

Feel free to carry on if you like .... I'm done here.

 

[sandorski]

What if it doesn't have Clearance?

 

[WelshBloke]

I really am getting the impression you don't understand how flight works.
(YOU started the "serious" part of this conversation)

Except in the case of a rocket-plane or a helicopter/VTOL WINGS provide lift not "massive thrust" and I'm not sure where the "equal resistance" thing was going lol. (even with a helicopter the same "lift" principle applies)

Look at it this way...
Forward force .....massive thrust of engines pushing against the air.
Backwards force.... Air resistance and?

The forward force here is... well the force that moves the plane forward. The wings turn that forward motion into lift. As long as theres forward motion there will be lift. A treadmill for a plane will not stop forward motion.

 

[[DHT]Osiris]

A fixed wing aircraft without VTOL has to physically move forward to generate lift and take off. No forward movement, no lift, no go up today.

 

[Captante]

The forward force here is... well the force that moves the plane forward. The wings turn that forward motion into lift. As long as theres forward motion there will be lift. A treadmill for a plane will not stop forward motion.

I'm thinking that you've entirely missed the point here.

Just sayin.


*(I literally couldn't care less if the plane takes off.... also if you put ketchup on a hot dog or approve of tipping either!)

 

[WelshBloke]

A fixed wing aircraft without VTOL has to physically move forward to generate lift and take off. No forward movement, no lift, no go up today.

Why wouldnt it go forward?

 

[[DHT]Osiris]

Why wouldnt it go forward?

Because it's on a hypothetical treadmill that's offsetting the forward thrust of the engine with an equivalent reversion of the wheels; the crux of the whole plane treadmill thing.

 

[Captante]

Why wouldnt it go forward?

Because you touch yourself at night?

 

[WelshBloke]

Because it's on a hypothetical treadmill that's offsetting the forward thrust of the engine with an equivalent reversion of the wheels; the crux of the whole plane treadmill thing.

Why would the treadmill stop the aeroplane? The worst it would do is make the whels spin faster.

 

[WelshBloke]

Because you touch yourself at night?

There'd be a lot of plane disasters if that were the reason!

 

[[DHT]Osiris]

Why would the treadmill stop the aeroplane? The worst it would do is make the whels spin faster.

It wouldn't stop the airplane but it would prevent it from taking off, if it was keeping the plane in place.

If it couldn't, the plane would move forward, generate lift, and take off.

 

[WelshBloke]

It wouldn't stop the airplane but it would prevent it from taking off, if it was keeping the plane in place.

If it couldn't, the plane would move forward, generate lift, and take off.

How would it keep the aeroplane in place?

 

[lxskllr]

Has it been stated whether or not the treadmill is powered? I think it makes a difference. A powered treadmill, the plane stays on the ground. A passive treadmill, the plane takes off.

edit:
I think... This question pisses me off. I see it popup every so often, I half assed look, then confuse myself thinking about nonsense.

 

[[DHT]Osiris]

How would it keep the aeroplane in place?

By preventing forward movement via 'reverse' movement on the wheels inducing enough friction to maintain equilibrium between forward and reverse movement.

 

[Captante]

Has it been stated whether or not the treadmill is powered? I think it makes a difference. A powered treadmill, the plane stays on the ground. A passive REALLY REALLY LONG, WIDE AND SMOOTH treadmill, the plane takes off.

At which point said "treadmill" becomes virtually identical to a runway (moving under power or not) negating any sort of logic .... we already know planes take off from runways!

 

[WelshBloke]

By preventing forward movement via 'reverse' movement on the wheels inducing enough friction to maintain equilibrium between forward and reverse movement.

So rotational friction in the bearing would be equal to at least one jet engine at full throttle?

 

[[DHT]Osiris]

At which point said "treadmill" becomes virtually identical to a runway (moving under power or not) negating any sort of logic .... we already know planes take off from runways!

Indeed, a passive treadmill is just a greasy runway.

 

[[DHT]Osiris]

So rotational friction in the bearing would be equal to at least one jet engine at full throttle?

If it's sufficiently fast and the bearings don't melt, sure. It's completely impractical mind you and an illogical argument, it's just the posited one.

Back to basics, aircraft needs forward movement to generate lift. Doesn't matter how much force is behind it, no movement, no lift.

 

[IronWing]

A super fast treadmill would entrain air near its surface (boundary layer and all that) providing a slight head wind for the plane and a corresponding increase in lift. So not only would the plane takeoff, it would take off more easily than on a fixed runway.

 

[[DHT]Osiris]

A super fast treadmill would entrain air near its surface (boundary layer and all that) providing a slight head wind for the plane and a corresponding increase in lift. So not only would the plane takeoff, it would take off more easily than on a fixed runway.

Any treadmill that could reach jet engine thrust * friction loss coefficient would likely need to be low enough drag to not realistically interfere with air. It's all fantasy land anyhow though.

 

[igor_kavinski]

Here’s The Actual Science Behind That Plane Takeoff Meme You Keep Seeing

A meme about whether an airplane can take off on a treadmill has been going around social media lately, tearing friendships apart with its divisiveness, ruining families and sending the world further into chaos. But now it’s time to put an end to the madness. Let’s look at the science!

jalopnik.com

The 747 on the conveyor belt dilemma solved with Simcenter Amesim | Bsim Engineering

bsim-engineering.com

The Goddamn Airplane on the Goddamn Treadmill

Sorry for the forum/blog downtime today. Many things went wrong during davean’s heroic upgrade. (I blame the LHC.) Feynman used to tell a story about a simple lawn-sprinkler physics problem. …

blog.xkcd.com

There. Settled.

Stop. Bickering. Guys.

 

[Fenixgoon]

1) some of y'all need to retake physics.
2) this thread needs to be locked

 

[Captante]

2) this thread needs to be locked

Not quite yet! *(one "definitive" answer incoming!)

I watched this episode when it originally aired fyi.

 

[skyking]

None of you yoots are pilots. You don't know shizzle about planes.
I hear all this talk about thrust ( ooh sexy ) and drag, the lower pressure above the wing, Bernoulli's principle.
None of that shit matters.
If the pilot does not have his wallet it will fall out of the sky like a stone. Those things fly on money.

 

[Captante]

Next time you see a thread on this topic, try to recall the following bit of age-old ATOT wisdom!