BF2S Forums Mythbusters finally tests the myth of.....

twiistaaa wrote:

what if you put some type of fan infront of the treadmill?

It would work even better to put the treadmill in a wind tunnel... that way you can get sufficient air flow over the wings to create lift.  It doesnt matter that it wouldnt be moving relative to the tunnel, what matters is the plane's speed relative to the air.

Last edited by adam1503 (2008-01-23 19:41:20)

adam1503 wrote:

BlackKoala wrote:

adam1503 wrote:

The plane can only fly if it gets lift, and that is achieved by air passing over the wings.  So if its moving on a treadmill, its moving relative to the belt, but stationary relative to the air... so I dont think it can fly.

Watch the video I posted.  It's only moving relative to the belt until it gets to speed, and after that point it's completely independent of the belt and can move forward with thrust increase, as a plane on flat ground could.

Thats right, when the plane is moving with exactly the opposite velocity of the belt, it is stationary relative to the room.  The plane wont take off, however, as there is no lift generated.

Watch the video.

He gets the plane to stay stationary on the treadmill at 3MPH. 

He increases the speed of the treadmill to 9MPH, whilst NOT TOUCHING THE THROTTLE OF THE PLANE.

The plane remains stationary on the treadmill.  He then increased the throttle of the plane, and the plane skated forward across the treadmill with little effort.

He just proved that the speed of the treadmill has no bearing on the myth.  Add throttle, the plane moves forward.  End of story.  We can both agree that a plane in motion can generate lift, correct?


It's like if you put a hot wheels on a treadmill, and held it down with your finger.  Your finger is there to act as the initial burst of energy required to break the rolling friction of the wheels.  Imagine this as getting the plane's engine idling to break the friction.  You can then move the car forward with that finger, and imagine that as increasing the thrust of the plane engine.

V wrote:

That had nothing to do with lift. Infact if anything it showed that the plane gained no lift.

Correct.  But it was proven that the plane moves completely independently of the treadmill.  Meaning given the room, the plane will take off, absolutely no doubts about it.

Anyone who expected the plane to take off without moving on the tread mill...hell that could have been proven wrong by just removing the wheels from a plane, lol.

Last edited by BlackKoala (2008-01-23 19:45:01)

the plane will not fly if it is going the same speed as the treadmill because the plane will stay in the exact same position and thus there will be no air going by the wings thus creating no lift. But if the plane goes faster than the speed of the treadmill and starts moving forward, air will start moving by the wings, and if the plane goes fast enough there will be enough life generated to take off.

IN SHORT: If the plane goes the same speed as the treadmill the plane will not take off, but if it goes alot faster than the treadmill the plane will take off.

Last edited by RandomSchl (2008-01-23 19:46:22)

adam1503 wrote:

twiistaaa wrote:

what if you put some type of fan infront of the treadmill?

It would work even better to put the treadmill in a wind tunnel... that way you can get sufficient air flow over the wings to create lift.  It doesnt matter that it wouldnt be moving relative to the tunnel, what matters is the plane's speed relative to the air.

ok but once it lifts of it has no forward momentum and the wind will push it back. the plane has a significant amount more drag off the ground so it still wont sustain flight.

Flaming_Maniac wrote:

The premise of the question states the plane is stationary relative to the ground. Moving the plane around, whether it has the ability to or not, is contradictory to the original conditions.

ATG Post wrote:

A plane is standing on a runway that can move (like a giant conveyor
belt). This conveyor has a control system that tracks the plane's
speed and tunes the speed of the conveyor to be exactly the same (but
in the opposite direction).

I see nothing about the plane being stationary.

Flaming_Maniac wrote:

The premise of the question states the plane is stationary relative to the ground. Moving the plane around, whether it has the ability to or not, is contradictory to the original conditions.

Miguel Diaz wrote:

Miguel Diaz wrote:

tbh in the thread he says the plane is standing on a treadmill, standing implies lack of motion, he never mentions the plane accelerating, therefore in this problem neither the plane nor the treadmill are moving and therefore the plane will not lift off.

"This conveyor has a control system that tracks the plane's
speed and tunes the speed of the conveyor to be exactly the same (but
in the opposite direction)."

the conveyor belt matches the plane's speed which is not moving "A plane is standing on a runway that can move"

Flaming_Maniac wrote:

BlackKoala wrote:

Flaming_Maniac wrote:

The premise of the question states the plane is stationary relative to the ground. Moving the plane around, whether it has the ability to or not, is contradictory to the original conditions.

ATG Post wrote:

A plane is standing on a runway that can move (like a giant conveyor
belt). This conveyor has a control system that tracks the plane's
speed and tunes the speed of the conveyor to be exactly the same (but
in the opposite direction).

I see nothing about the plane being stationary.

Okay, give me a speed of the plane wheels where the plane is not stationary.

??? 

As long as the plane wheels are moving, the plane can skate across the treadmill with a throttle increase. 

It's just the initial friction that needs to be broken, as I doubt there's enough friction in the wheels of a plane to over power the force of the engine.  As soon as that gets broken, the speed of the treadmill is completely irrelevant and the plane can move as if it's on a normal runway.

BlackKoala wrote:

Flaming_Maniac wrote:

BlackKoala wrote:

Flaming_Maniac wrote:

The premise of the question states the plane is stationary relative to the ground. Moving the plane around, whether it has the ability to or not, is contradictory to the original conditions.

I see nothing about the plane being stationary.

Okay, give me a speed of the plane wheels where the plane is not stationary.

??? 

As long as the plane wheels are moving, the plane can skate across the treadmill with a throttle increase. 

It's just the initial friction that needs to be broken, as I doubt there's enough friction in the wheels of a plane to over power the force of the engine.  As soon as that gets broken, the speed of the treadmill is completely irrelevant and the plane can move as if it's on a normal runway.

When the throttle is increased by x, the treadmill speed is increased by x as well.

Flaming_Maniac wrote:

BlackKoala wrote:

Flaming_Maniac wrote:

Okay, give me a speed of the plane wheels where the plane is not stationary.

??? 

As long as the plane wheels are moving, the plane can skate across the treadmill with a throttle increase. 

It's just the initial friction that needs to be broken, as I doubt there's enough friction in the wheels of a plane to over power the force of the engine.  As soon as that gets broken, the speed of the treadmill is completely irrelevant and the plane can move as if it's on a normal runway.

When the throttle is increased by x, the treadmill speed is increased by x as well.

Watch the video again, please.  I beg of you Maniac.

He increased the speed of the treadmill, and DID NOT TOUCH THE PLANE THROTTLE.  The plane STAYED STILL.
He then increased the plane throttle; and the plane MOVED.

The video has nothing to do with whether the plane will take off from a conveyor belt or not.  That question has already been answered, so we need to stop debating it before it gets out of hand.

Last edited by adam1503 (2008-01-23 20:05:24)

/sigh

I guess we can't debate this without calling each other stupid, young, and smart-asses.