Does the plane REALLY take off? It depends.

[IronWing]

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

I watched this episode when it originally aired fyi.

Mythbusters couldn’t even do the fan on a sailboat test correctly and we’re supposed to rely on them for the most important physics question of our time?

 

[Captante]

Mythbusters couldn’t even do the fan on a sailboat test correctly and we’re supposed to rely on them for the most important physics question of our time?

Yep.

 

[pete6032]

Aeroplane is going to go forward, aeroplane don't give a shit about wheels.

Aeroplane

 

[Captante]

Aeroplane

 

[sdifox]

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

The Earth is a giant treadmill.

 

[[DHT]Osiris]

The Earth is a giant treadmill.

So is our galaxy.

 

[SKORPI0]

Another sites thread from Dec 2005.

Can the Plane Take-Off?

Ummm… Don, I don’t see how you can say that the belt can move at any speed. The condition says that the speed of the conveyor is (effectively) the negative of the speed of the airplane. It does not say that the conveyor goes fast enough to stop the plane with friction. It does not say that the...

www.chiefdelphi.com

 

[sdifox]

So is our galaxy.

Yet planes take off all the time

 

[[DHT]Osiris]

Another sites thread from Dec 2005.

View attachment 79558

Can the Plane Take-Off?

Ummm… Don, I don’t see how you can say that the belt can move at any speed. The condition says that the speed of the conveyor is (effectively) the negative of the speed of the airplane. It does not say that the conveyor goes fast enough to stop the plane with friction. It does not say that the...

www.chiefdelphi.com

That does assume frictionless wheel bearings, but it's correct if you assume that.

 

[sdifox]

That does assume frictionless wheel bearings, but it's correct if you assume that.

Wheels exist to reduce friction. All it does is reduce takeoff distance.

 

[[DHT]Osiris]

Wheels exist to reduce friction. All it does is reduce takeoff distance.

Yeah but they aren't frictionless themselves. If you had an unbraked plane with no thrust (turned off) and you fired up the conveyor belt backwards at 10 mph, it'd go backwards, probably slowly at first but eventually the wheels would stop rolling and it'd hit -10mph, necessitating forward thrust of 10mph to stay still. Extrapolate from there.

 

[sdifox]

What if it doesn't have Clearance?

Answer: Harrison Ford

 

[sdifox]

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

Says the troll

 

[sdifox]

Yeah but they aren't frictionless themselves. If you had an unbraked plane with no thrust (turned off) and you fired up the conveyor belt backwards at 10 mph, it'd go backwards, probably slowly at first but eventually the wheels would stop rolling and it'd hit -10mph, necessitating forward thrust of 10mph to stay still. Extrapolate from there.

Airplane without thrust is just a big piece of solid, of course it is going to move backwards. But once you turn on the engine/turbine, the trust will reduce the backward motion until such time it starts moving forward and eventually take off. Like I sade, the onky difference is the "distance" travelled before takeoff.

 

[[DHT]Osiris]

Airplane without trust is just a big piece of solid, of course it is going to move backwards. But once you turn on the engine/turbine, the trust will reduce the backward motion until such time it starts moving forward and eventually take off. Like I sade, the onky difference is the "distance" travelled before takeoff.

..As long as the forward thrust exceeds the reverse momentum/drag from the treadmill. Again, this is the point of the thought exercise. Many people seem to believe that takeoff speed = wheel speed rather than air speed.

 

[sdifox]

..As long as the forward thrust exceeds the reverse momentum/drag from the treadmill. Again, this is the point of the thought exercise. Many people seem to believe that takeoff speed = wheel speed rather than air speed.

Stand a F-22 on its end and it can do vertical takeoff given its greater than 1 thrust to weight ratio. There, treadmill eliminated.

 

[IronWing]

What if it doesn't have Clearance?

What's its vector?

 

[sdifox]

What's its vector?

First Jive Dude : Say 'e can't hang, say seven up!

Jive Lady : Jive-ass dude don't got no brains anyhow!

 

[TheELF]

What's its vector?

Roger Murdock : Flight 2-0-9'er, you are cleared for take-off.
Captain Oveur : Roger!
Roger Murdock : Huh?
Tower voice : L.A. departure frequency, 123 point 9'er.
Captain Oveur : Roger!
Roger Murdock : Huh?
Victor Basta : Request vector, over.
Captain Oveur : What?
Tower voice : Flight 2-0-9'er cleared for vector 324.
Roger Murdock : We have clearance, Clarence.
Captain Oveur : Roger, Roger. What's our vector, Victor?
Tower voice : Tower's radio clearance, over!
Captain Oveur : That's Clarence Oveur. Over.
Tower voice : Over.
Captain Oveur : Roger.
Roger Murdock : Huh?
Tower voice : Roger, over!
Roger Murdock : What?
Captain Oveur : Huh?
Victor Basta : Who?

 

[darkswordsman17]

Is this some new right wing dumbfuck conspiracy that we live on a conveyor belt Earth or some shit now to try and explain why morons like the OP that don't believe in evolution but do believe in Elon Musk fucking his way to a master race?

 

[[DHT]Osiris]

Stand a F-22 on its end and it can do vertical takeoff given its greater than 1 thrust to weight ratio. There, treadmill eliminated.

Yeah I included a caveat for VTOL up above.

 

[sandorski]

Can a VTOL take off from an Elevator going Up?

 

[IronWing]

Can a VTOL take off from an Elevator going Up?

If the elevator is traveling upwards at a constant velocity then yes. If the elevator is accelerating upwards at a rate that overcomes the thrust of the engines then no. Somewhere in between, the plane will burn up from the heat of its engines.

 

[zinfamous]

My only "argument" is that without adding in some near-physically impossible "conditions" any "taking off" is 100% hypothetical without a practical means of providing lift to the wings.

And I've yet to hear even one for 99% of real aircraft.

lol. I don't understand if you are trolling or not but you do understand that in the thought experiment, the wheels and friction and the treadmill are all essentially meaningless. The plane moves forward regardless of any of that because the wheels aren't fixed.

We know this by now, right?

right?

 

[zinfamous]

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.

did you guys get hit in the head or something? This is old, lol. We know that the treadmill and the wheels are irrelevant. That's the point of the question--it's a silly distraction that is meant to shut down your brain at the simplest point: the wheels are actually meaningless, as is the treadmill.