If an AIRPLANE is on a TREADMILL will it take off? (Physics)

[NoobGains23]

I missed nothing. It's all about lift from the airfoils.

A plane WILL take off when NOT rolling if enough air speed over the airfoils is provided.

Wheels moving doesn't matter.


I must be getting trolled, I'm done here. I don't care if anyone gets it or not.

This. A small prop plane which needs 150mph of airflow to take off could take off at 50mph rolling ground speed if there is a 100mph wind blowing towards it.
Take that exact same scenario, on a treadmill, if said treadmill is moving at 150mph the plane wont take off since the treadmill creates no airflow.
Simples and also done since too many potatoes ITT

[DancerInTheDark]

Try placing a 45lb plate on a running treadmill and pushing it forward...good luck. Set that same plate on a skateboard and do the same thing, piece of cake. Crank the speed up on the treadmill until the skateboard wheel bearings melt, well then, we're back to good luck. Friction of the bearings and rolling resistance of the tires are they keys here, along with their mechanical limits. There is no definitive answer though because OP doesn't provide enough boundary conditions, so, assuming the bearings won't go all Chernobyl and the tires don't explode, we are left with the following scenarios...

1) If the plane cannot create enough thrust to overcome the friction/rolling resistance of the wheels created by the moving treadmill, the plane actually rolls backwards
2) If the plane thrust equals the friction/rolling resistance of the wheels created by the moving treadmill, the plane sits still
3) If the plane creates enough thrust to overcome the friction/rolling resistance of the wheels created by the moving treadmill, but not enough to move the plane forward fast enough to create lift from air movement over the wings, the plane simply rolls forward
4) If the plane creates enough thrust to overcome the friction/rolling resistance of the wheels created by the moving treadmill AND the plane moves forward fast enough to create lift from air movement over the wings, the plane takes off and flies to North Carolina
5) OP is a *******

^ This

[MrGreenz]

In a day to day scenario (or more importantly in the treadmill scenario) the planes rolling speed is most important.

Thats why i said earlier in the thread (must have been missed) that a better question would be, 'If there was a huge fan creating 200mph of airflow, would the plane take off?'.
Yes it would, might not go forward but it would lift off at least.

If a treadmill has a fixed speed of 600mph, the planes jet engines have a fixed rolling speed of 400mph.
The plane needs 600mph of airflow to take off.
There is a fan as well as the treadmill which puts out 200mph of airflow
The plane takes off from a stationary position. As soon as it leaves the treadmill, it now has all that energy that was used on the treadmill (via the jet engines) which can be used as forward thrust.

I'm 95% sure your trolling, but just out of intrest;

what do you propose is counteracting the 100's of kN thrust?

[LaCosaNostra90]

1st video = takeoff

2nd video = no takeoff

Did you not understand the second video? the plane moved forward regardless of the treadmill speed. if the treadmill was longer it would take off

[MrGreenz]

I missed nothing. It's all about lift from the airfoils.

A plane WILL take off when NOT rolling if enough air speed over the airfoils is provided.

Wheels moving doesn't matter.


I must be getting trolled, I'm done here. I don't care if anyone gets it or not.

SO how is saying that they rely on rolling ground speed not incorrect.

[DancerInTheDark]

This video shows it better than the myth busters video. Once you have enough thrust to overcome the frictional resistance of the bearings of the wheels, you don't have to increase thrust to match the speed of the tread mill. You can keep throttle constant and continually raise the speed of the treadmill, and the plane wont move. It will take off once thrust is increased, even if the speed of the treadmill is increased to try to match the plane.

This one is interesting though. I understand jack **** of airplane radio controls, but you affirm that throttle stays the same regardless of treadmill speed ? It's true that speed dependence is not very strong at low speed and treadmill speed range is limited, but still ... !

[chroneos]

Did you not understand the second video? the plane moved forward regardless of the treadmill speed. if the treadmill was longer it would take off

didnt listen, just saw no takeoff

[NoobGains23]

I'm 95% sure your trolling, but just out of intrest;

what do you propose is counteracting the 100's of kN thrust?

You are wearing rollerblades on a treadmill.
Rollerblades have a jet engine on both
Full thrust on jet engines on rollerblades which = 200mph
Treadmill matches 200mph instantly.
You remain on the treadmill.
You think 'no dats wrong'
You put wings on your rollerblades
I light a poverty lighter under your rollerblade wings
No airflow blows the flame out

/thread

[Kavliari]

Not sherrif srs or 2nd grade reading comprehension.. FINE. say instead of pushing it off the edge, I threw it as hard as I could and it had toy plane wings on it. IT WOULD TAKE OFF. Treadmill has to be long, but it will take off the same as if it was on the ground. I'm running out of ways to simplify this so a child can understand.



lol if you tie a normal plane to the ground it's not gonna take off either. troll video

Infinite velocity is not a reality in this situation, there are limits.

If the plane can generate enough velocity to travel faster than the treadmill, enough so that the required amount of lift is generated under the wings and the treadmill is long enough to facilitate such an absurd occurrence.... then yes, it will take off and everybody understands that. In reality the likelihood of it happening is extremely low when you consider the number of rotations per minute the wheels on the plane would have to withstand.

[Brozef]

As long as the plane can accelerate on the belt fast enough too create lift, then OF COURSE it will take off.

[MrGreenz]

You are wearing rollerblades on a treadmill.
Rollerblades have a jet engine on both
Full thrust on jet engines on rollerblades which = 200mph
Treadmill matches 200mph instantly.
You remain on the treadmill.
You think 'no dats wrong'
You put wings on your rollerblades
I light a poverty lighter under your rollerblade wings
No airflow blows the flame out

/thread

Formally stated, Newton's third law is: For every action, there is an equal and opposite reaction. The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object.


read up cuz

[chappy86]

No. Aircraft req lift which is caused by air flow. On a treadmill the tires would just rotate. Any adult thats not full pledged brain dead should lnow this.


Exp- Aircraft Mechanic

[NoobGains23]

Formally stated, Newton's third law is: For every action, there is an equal and opposite reaction. The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object.


read up cuz

Troll confirmed. Its been fun

[digistp]

[5431]

back in my day, trolling used to mean something.

[MrGreenz]

Troll confirmed. Its been fun

Untill you tell me what is opposing the force of the thrust I consider you the troll.

[naths]

Came in to post "Of course it will take off *******" because obviously if you had any idea of physics and motion at all you would know that I was being sarcastic.

But considering this is the misc, I have to explain what I wanted to post because there seems to be arguments about this.

I shall explain why you can't in laymens terms for the misc:

Planes need air pressure to take off, air pressure is literally the act of pushing a solid object through a pocket of air, if you are stagnant, you will not generate enough air pressure to be able to get the plane off the ground. Being stagnant is the act of not moving. If a plane was stagnant, it would either be turned off, or if it was in motion, would have to have enough force going the opposite direction.

Treadmills do not generate air pressure.

If you were to sit a plane on a conveyor belt that only moved when pressure was exerted (aka the wheels on the plane - once the plane starts moving, cause the belt to start to spin at the same speed of the wheels) you would have a stagnant plane. UNLESS there was air pressure moving at a certain speed against the plane (aka 500km/hour) the plane would not take off.

If you sat a plane in a combustion chamber, with a conveyor belt, and enough air pressure to push against the plane, the plane would begin to fly on it's own.

Without that chamber, having only a treadmill or conveyor belt - the plane would be moving absolutely bum fukk nowhere.

EDIT: Holy fukk, are people actually HONESTLY trying to say that the plane would take off. People are way more stupid than I initially thought.

[PrimeraRS]

Came in to post "Of course it will take off *******" because obviously if you had any idea of physics and motion at all you would know that I was being sarcastic.

But considering this is the misc, I have to explain what I wanted to post because there seems to be arguments about this.

I shall explain why you can't in laymens terms for the misc:

Planes need air pressure to take off, air pressure is literally the act of pushing a solid object through a pocket of air, if you are stagnant, you will not generate enough air pressure to be able to get the plane off the ground. Being stagnant is the act of not moving. If a plane was stagnant, it would either be turned off, or if it was in motion, would have to have enough force going the opposite direction.

Treadmills do not generate air pressure.

If you were to sit a plane on a conveyor belt that only moved when pressure was exerted (aka the wheels on the plane - once the plane starts moving, cause the belt to start to spin at the same speed of the wheels) you would have a stagnant plane. UNLESS there was air pressure moving at a certain speed against the plane (aka 500km/hour) the plane would not take off.

If you sat a plane in a combustion chamber, with a conveyor belt, and enough air pressure to push against the plane, the plane would begin to fly on it's own.

Without that chamber, having only a treadmill or conveyor belt - the plane would be moving absolutely bum fukk nowhere.

EDIT: Holy fukk, are people actually HONESTLY trying to say that the plane would take off. People are way more stupid than I initially thought.

lol yeah apparently a STATIONARY plane can generate lift on the misc

[dhawkeye1980]

Only if you have a super long treadmill and the plane starts moving forward

Thats a convayer belt not a treadmill then

[travis976]

This has already been solved by the misc quite some time ago..

[ironicinori]

You are wearing rollerblades on a treadmill.
Rollerblades have a jet engine on both
Full thrust on jet engines on rollerblades which = 200mph
Treadmill matches 200mph instantly.
You remain on the treadmill.
You think 'no dats wrong'
You put wings on your rollerblades
I light a poverty lighter under your rollerblade wings
No airflow blows the flame out

/thread

Ok.
You hold onto the sides of the treadmill while it's on at 200 mph. It takes almost no effort because you have sick ABEC-5 blades and have little friction (i think we all agreed we're ignoring friction here).

Whether the treadmill is going 20mph or 200mph, it still takes the same effort to hold you in place. SO, however fast the treadmill moves, it will take the same force to move you forward in relation to the rest of the gym.

NOW you turn the jet engines on. You don't stay in the same spot, you move forward off the front of the treadmill.

If the treadmill was a mile long, and you had wings, you'd take off.

lol yeah apparently a STATIONARY plane can generate lift on the misc

I know you came in late, but the whole point is the plane will never be stationary. It's physically impossible to keep a plane stationary on a treadmill. If you had a mile long treadmill next to a mile long runway, and two planes taking off next to each other, it would look the exact same to everybody there. The treadmill plane isn't jetting in place.

[MrGreenz]

The sticking point of the question is whether or not the plane will move with the constraints of fantasy treadmills.

The people explaining the mechanics of lift are 1 step behind, arguing a mechanic that is not in question (at least in my mind). If the plane moves forward then it accelerates and generates lift. If it doesn't move relative to the air around it, then it doesn't generate lift.

[Trojans86]

I keep going back and forth on whether or not some of you are for real. We obviously have some trolls but im still not sure about the rest of you.

1) the treadmill isnt pushing the plane and providing counterthrust, the treadmill is rotating the wheels which does not have any impact on moving the plane or not
2) the plane is thrusted forward by its engines. Once it gets moving forward, its speed is measured relative to the air that it is pushing away from, not the treadmill. Since the treadmill machine isnt moving, the plane's speed is also measured against the treadmill belt. So if the plane gets up to 1mph, that means it is always moving 1mph faster than whatever speed the treadmill belt is moving. In that scenario the treadmill belt cannot match the speed of the wheels
3) since the plane is moving forward, it is creating airflow under its wings.

[Trojans86]

You IDIOTS


You are asking two separate questions, you are supposed to be an engineer god help our development.

Your answer is assuming the plane will still move forward, enough to create wind over the wings and create lift. In that scenario, sure, the plane will be moving forward just like on a runway, with just the independent wheels spinning faster than they normally would if the ground weren't moving.

The hypothetical question involved implies that the plane is holding still, and the only movement is the ground going backwards under it via tredmill, in this scenario there is no lift, the plane does not take off.




How can so many of you engineering studends be so dumb, that you can't even understand the scenario, and can't provide a logical answer.



You're answering different questions. The first question never suggests the plane has a full runway to move forward on. It's implying it's holding still, and you damn well know it.


/end of this thread, forever.

No one is asking what would happen if the plane were held still, they are asking if you turned on the engine would the plane take off. What happens when the engine is turned on.

[chroneos]

This has already been solved by the misc quite some time ago..

Apparently not.

[heyyouwhome]

At first I thought the plane would not take off because the wheels speed would match the treadmill speed. But then I realized the reason it's confusing is because the engines and the wheels are two separate and independent systems. So the thrust from the engines would pull the plane forward regardless of the speed of the treadmill/wheels. The treadmill/wheels could be going 1 million miles an hour, doesn't matter because the plane will be stationary. Then once the thrust is activated the wheels become irrelevant because now you're dealing with the engine and the air which causes the movement not the wheels and the treadmill.

The question would be the same if you replaced it with a human on a treadmill who had bionic wings he could flap while running on the treadmill. Then the question becomes so simple and obvious it's silly. Of course he could flap his wings and fly away, because his wings are independent of his legs. Doesn't matter how fast he's running on the treadmill or the ground, if he has the lift he will fly away. Same with the plane


The answer is yes the plane would take off, but it would have to roll off the treadmill first to gain any speed before takeoff, no air flow = no lift

[Postmort3m]

Obviously the treadmill has to be on the highest incline

[JewishSuperHero]

This. A small prop plane which needs 150mph of airflow to take off could take off at 50mph rolling ground speed if there is a 100mph wind blowing towards it.
Take that exact same scenario, on a treadmill, if said treadmill is moving at 150mph the plane wont take off since the treadmill creates no airflow.
Simples and also done since too many potatoes ITT

The turbines create the airflow. Not the wheels.

[shibby19]

This one is interesting though. I understand jack **** of airplane radio controls, but you affirm that throttle stays the same regardless of treadmill speed ? It's true that speed dependence is not very strong at low speed and treadmill speed range is limited, but still ... !

Yes, he did not increase the throttle of the plane when he increased the speed of the treadmill. Once there's enough thrust to overcome the friction of the bearings, you can raise the treadmill speed to 1000 mph (assuming some amazing ball bearing that wouldn't melt) without increasing throttle to the plane and the plane will stay exactly where it is, the wheels will just rotate faster to compensate.

People that think the plane wont take off don't take this in to account. Once you have enough thrust to get the wheels moving, there is no longer a connection between the wheels of the plane and the thrust of the engines. At this point, any added thrust will propel the plane forward, no matter how much the speed of the treadmill increases.

[RS8]

6 pages later and misc still doesn't realize the question was too vague