A question...

[BLLDOGG]

thats you pulling yourself with a stationary movement. not the same so dont try to add stationary things into this to prove a point [img]tongue.gif[/img]

[98Camaro3.8]

Originally posted by BLLDOGG:
not the same so dont try to add stationary things into this to prove a point

The air is stationary. That's exactly what the propeller is doing! [img]smile.gif[/img]

[BLLDOGG]

Originally posted by 98Camaro3.8:
</font><blockquote>quote:</font><hr />Originally posted by v6man:
what do you thing would happen if you didnt tie your car down on the dyno and the drum was to just free spin. your car would remain in place.

You can't use a car here, because a car acts on the ground, not on the air. That's a big difference.


The question says the treadmill moves at the same speed as the airplane. So when the airplane is moving forward at 10 mph, the treadmill is moving 10 mph in the other direction. The airplane is actually moving forward at 10 mph, just the wheels are rolling at 20 mph. </font>[/QUOTE]but the plane isnt moving at 10mph. its at 0mph trying to gain speed for flight. but when any foreward movement is produced, it is counteracted by the treadmill

[MTMike]

Originally posted by BLLDOGG:
thats you pulling yourself with a stationary movement. not the same so dont try to add stationary things into this to prove a point [img]tongue.gif[/img]

The prop/jet engine uses stationary air to create thrust, thus pushing the plane foward through the stationary air. The only thing the landing gear does is keep the plane's belly from dragging on the ground.

If the plane's landing gear had any bearing on it's ability to fly, why do they fold up into it after takeoff? Also, explain water-takeoffs?

[BLLDOGG]

Originally posted by 98Camaro3.8:
</font><blockquote>quote:</font><hr />Originally posted by BLLDOGG:
not the same so dont try to add stationary things into this to prove a point

The air is stationary. That's exactly what the propeller is doing! [img]smile.gif[/img] </font>[/QUOTE]correct, a plane needs air movement across the wing to fly

[MTMike]

Originally posted by BLLDOGG:
</font><blockquote>quote:</font><hr />Originally posted by 98Camaro3.8:
</font><blockquote>quote:</font><hr />Originally posted by v6man:
what do you thing would happen if you didnt tie your car down on the dyno and the drum was to just free spin. your car would remain in place.

You can't use a car here, because a car acts on the ground, not on the air. That's a big difference.


The question says the treadmill moves at the same speed as the airplane. So when the airplane is moving forward at 10 mph, the treadmill is moving 10 mph in the other direction. The airplane is actually moving forward at 10 mph, just the wheels are rolling at 20 mph. </font>[/QUOTE]but the plane isnt moving at 10mph. its at 0mph trying to gain speed for flight. but when any foreward movement is produced, it is counteracted by the treadmill </font>[/QUOTE]BUt it's not! It only causes the landing gear to spin faster. The planes wheels "freewheel".

Discounting any friction, if the treadmill was moving at 1000mph and the plane's engine was off, the wheels would be turning 1000mph but the plane would not be moving backwards

[Fbody3400]

I'll add my 2 cents...

To the extent of my knowledge, a plan needs some sort of lift to leave the ground. Although the propeller/engine creates foward thrust, it doesn't create any type of lift. I don't think the plane would fly. A bird wouldn't just take off by running (if it could do that) on a tread mill with its wings out...

ps. If this is seriously a big thing, and its spreading across the internet, somebody should contact the mythbusters!

[v6man]

the propeller may be moving air but it is not enough while stationary to create lift. the propeller will only move enough air to cover the body and will not cover the wings.

the treadmill will counter act any movement as "it has a system that tracks the speed of the plane and matches it exactly in the opposite direction" so there is no way the plane will leave the treadmill.

[MTMike]

Originally posted by BLLDOGG:
</font><blockquote>quote:</font><hr />Originally posted by 98Camaro3.8:
</font><blockquote>quote:</font><hr />Originally posted by BLLDOGG:
not the same so dont try to add stationary things into this to prove a point

The air is stationary. That's exactly what the propeller is doing! [img]smile.gif[/img] </font>[/QUOTE]correct, a plane needs air movement across the wing to fly </font>[/QUOTE]yes, and it creates that movement of air by propelling air away from the plane. Every action has an equal and opposite reaction. The prop/jet engine thrusts on the air, creating an equal and opposite reaction (against the air) to move the plane foward, irresponsive to whether it's landing gear is on asphalt, a treadmill moving 1000000mph, or tucked inside of it's fuselage.

[fbird01]

lol i really dont see this as being something they would test large scale

[MTMike]

Originally posted by v6man:
the propeller may be moving air but it is not enough while stationary to create lift. the propeller will only move enough air to cover the body and will not cover the wings.

the treadmill will counter act any movement as "it has a system that tracks the speed of the plane and matches it exactly in the opposite direction" so there is no way the plane will leave the treadmill.

It doesnt need to creat lift... it needs to move tehe plane forward through the air to creat lift on the wings.

The planes prop moves the plane through air regardless of what it's landing gear is doing This is why planes can take off of water, off air craft carriers that are moving foward at 30mph, etc

[BLLDOGG]

Originally posted by MTMike:
</font><blockquote>quote:</font><hr />Originally posted by BLLDOGG:
thats you pulling yourself with a stationary movement. not the same so dont try to add stationary things into this to prove a point [img]tongue.gif[/img]

The prop/jet engine uses stationary air to create thrust, thus pushing the plane foward through the stationary air. The only thing the landing gear does is keep the plane's belly from dragging on the ground.

If the plane's landing gear had any bearing on it's ability to fly, why do they fold up into it after takeoff? Also, explain water-takeoffs? </font>[/QUOTE]i know it uses stationary air to push it forward and i do understand landing gear and water based takeoffs but even with the engine pulling in millions of cubic feet of air and producing 10 billion pounds of thrust, the treadmill is going to prevent the plane from moving forward. just like a person on a treadmill, you are producing the force to move you forward with your legs, you are in a scense moving because your feet are not touching the same spots everytime but in all reality, to didnt just move from next to the wall into your tv like you would when running on the ground. also, about landing, if you have a treadmill going at the same speed that you are running, if you run towards the treadmill and get on it in your running motion or whatever you want to call, you not going to keep moving foward right into your tv, through the wall and into the pool.

[98Camaro3.8]

Originally posted by v6man:
the propeller may be moving air but it is not enough while stationary to create lift. the propeller will only move enough air to cover the body and will not cover the wings.

the treadmill will counter act any movement as "it has a system that tracks the speed of the plane and matches it exactly in the opposite direction" so there is no way the plane will leave the treadmill.

The propeller isn't supposed to create lift (disregarding any tendencies of certain low wing aircraft). The propeller creates thrust (which is lift in the forward direction, but nevermind). This thrust is a force pulling the airplane forward. To remain stationary, there must be an equal force in the opposite direction. The rolling wheels do not create that much drag. There is still a net force of thrust which accelerates the airplane.


Let's say the airplane is cruising down the treadmill at 50 mph, but the treadmill isn't moving. Now make the treadmill go 10 mph. The airspeed of the airplane hasn't changed. It's still going 50 mph. The wheels are rolling faster, but the airplane is still going 50 mph.

[MTMike]

Originally posted by BLLDOGG:
</font><blockquote>quote:</font><hr />Originally posted by MTMike:
</font><blockquote>quote:</font><hr />Originally posted by BLLDOGG:
thats you pulling yourself with a stationary movement. not the same so dont try to add stationary things into this to prove a point [img]tongue.gif[/img]

The prop/jet engine uses stationary air to create thrust, thus pushing the plane foward through the stationary air. The only thing the landing gear does is keep the plane's belly from dragging on the ground.

If the plane's landing gear had any bearing on it's ability to fly, why do they fold up into it after takeoff? Also, explain water-takeoffs? </font>[/QUOTE]just like a person on a treadmill, you are producing the force to move you forward with your legs, you are in a scense moving because your feet are not touching the same spots everytime but in all reality, to didnt just move from next to the wall into your tv like you would when running on the ground. </font>[/QUOTE]But you are using the treadmill to make your forward movement when you're running on it. The plane is not

[98Camaro3.8]

Originally posted by BLLDOGG:
just like a person on a treadmill

No, you can't think of it that way. A person (or a car) applies force to the ground. The airplane is applying it to the air. The person would not move at all. The airplane would.


Damn you Mike for posting this here! :D [img]tongue.gif[/img]