Rack your brain...

[BART]

Originally Posted by texan_idiot25

Not the same concept, because in practice eventually the thrust of the real plane can make the the plane pull off the treadmill. In the question above the treadmill spins in sync with the speeds of the plane's engines. In otherwords, faster the engine, faster the treadmill

Yet the planes "airspeed" has nothing to do with the speed of the treadmill.

[KITT222]

look, im going by "the plane wont move if its on the treadmill" taking off has nothing to with it. besides, this is a crappy plane. the basic idea is the same.

[imstock]

i love chaos...

[urownstupidity]

Originally Posted by ZX9RBART

It does not matter how fast the turbine spins nor how fast the conveyor goes, the speed of the plane compared to the conveyor is irrelevant. The speed of the plane in relation to the ground (and therefore the air) never changes and the plane will never lift off. No increased airflow across the wings...no flight.

Edit; now wheres my cookie!

i agree the back flaps on the wings are what make it lift off the ground..and if theres no wind to push them then how could it take off....now i think if you take a huge fan and then try this it might just work ahaha

[kendallcschm]

its simple.... if the tread mill and nose of the plane are faceing in the same direction then the plane wont take off but if the plane is not parallel to the treadmill then it will take off... or if the engines get up enough power and at full throttle they might be able to get the plane to lift off depending on the speed of the treadmill.... too many variables....

[fiberworkz]

Originally Posted by kendallcschm

its simple.... if the tread mill and nose of the plane are faceing in the same direction then the plane wont take off but if the plane is not parallel to the treadmill then it will take off... or if the engines get up enough power and at full throttle they might be able to get the plane to lift off depending on the speed of the treadmill.... too many variables....

There are no variables. The treadmill can be spinning at any speed and it will still have absolutely no bearing on whether the airplane will take off or not. The plane will take off just like it would under normal conditions, the only difference will be the speed at which the tires turn.

[imstock]

The turbine would move the same amount of air, whether the plane is on a treadmill or not. The lateral movement of the plane would be hampered, but it would take off just the same (air still moves over the wing despite the treadmill, providing lift). Basically this would be a viable method for shortening runways for take off, landing would still need a lengthy runway though. :-)

[KITT222]

Originally Posted by imstock

The turbine would move the same amount of air, whether the plane is on a treadmill or not. The lateral movement of the plane would be hampered, but it would take off just the same (air still moves over the wing despite the treadmill, providing lift). Basically this would be a viable method for shortening runways for take off, landing would still need a lengthy runway though. :-)

it wouldnt shorten them.. everything would be the same except for wheel's speed.

[meme405]

Originally Posted by KITT222

it wouldnt shorten them.. everything would be the same except for wheel's speed.

HUH???

If the plane stays stationary on a 35m treadmill i believe thats shorter than the what, 1km runways we have now...

The plane takes off just the same...

[theoriganalRiD3R1967]

Originally Posted by imstock

(air still moves over the wing despite the treadmill, providing lift)

what makes the air move (in relation to the wing), and i thought air must be under the wing, am i wrong?

[imstock]

Originally Posted by KITT222

it wouldnt shorten them.. everything would be the same except for wheel's speed.

If an airplane gains 3 tons of lift within a 10,000 runway, then it will create the same amount of lift on a >100 foot runway if the speed of the pavement matched the forward momentum of the plane.

Originally Posted by theoriganalRiD3R1967

what makes the air move (in relation to the wing), and i thought air must be under the wing, am i wrong?

Air moves faster under the wing then above which creates lift.

[BART]

Originally Posted by imstock

If an airplane gains 3 tons of lift within a 10,000 runway, then it will create the same amount of lift on a >100 foot runway if the speed of the pavement matched the forward momentum of the plane.



Air moves faster under the wing then above which creates lift.

So are you trying to say that the movement of the ground will change the airflow? Not in any noticeable manner as proved by simple physics. The earth is spinning at over 1000 mph, so why woulnt take off distances be different from east to west? The treadmill or moving runway would have no effect other than that which would be lost through frictional increases at the wheel.

[imstock]

Originally Posted by ZX9RBART

So are you trying to say that the movement of the ground will change the airflow? Not in any noticeable manner as proved by simple physics. The earth is spinning at over 1000 mph, so why woulnt take off distances be different from east to west? The treadmill or moving runway would have no effect other than that which would be lost through frictional increases at the wheel.

Simple physics. If the force created by the prop generates 10mph forward movement, and the treadmill is rotating at 10mph, the lift needed would be obtained while the plane was stationary on the rotating treadmill. Dont get confused by forward momentum and lift, they have nothing to do with one another. Easy way to understand this is to watch the experiment done using scale aircraft. You can essentially reduce the area needed for take off down to a few feet (scaled).

[BART]

Originally Posted by imstock

Simple physics. If the force created by the prop generates 10mph forward movement, and the treadmill is rotating at 10mph, the lift needed would be obtained while the plane was stationary on the rotating treadmill. Dont get confused by forward momentum and lift, they have nothing to do with one another. Easy way to understand this is to watch the experiment done using scale aircraft. You can essentially reduce the area needed for take off down to a few feet (scaled).

The 10 mph is ground speed measured on the treadmill, the airspeed over the wings at this point is 0. the plane will not fly without air passing over (and under) the wings. The treadmill creates no air to flow across the wings hence not increasing nor decreasing takeoff distance (disregarding frictional losses at the wheels)

[BART]

Man up. Argue or defeat?

[imstock]

http://www.youtube.com/results?searc...rch_type=&aq=f

[BART]

Originally Posted by imstock

http://www.youtube.com/results?searc...rch_type=&aq=f

We have established that it will take off but the distance the plane had to travel to reach liftoff did not change.

[imstock]

If it gains zero forward momentum on the treadmill, the distance it travels before take off is zero which is a lot less then it takes the average plane on a standard runway.

[BART]

Originally Posted by imstock

If it gains zero forward momentum on the treadmill, the distance it travels before take off is zero which is a lot less then it takes the average plane on a standard runway.

Why would it gain 0 forward momentum on the treadmill??? Even in the video it shows the plane moving forward. The plane has to travel through the "air" at a certain speed in order to have enough lift to take off. The speed the treadmill is moving underneath is completely irrelevant.

[imstock]

Originally Posted by ZX9RBART

Why would it gain 0 forward momentum on the treadmill??? Even in the video it shows the plane moving forward. The plane has to travel through the "air" at a certain speed in order to have enough lift to take off. The speed the treadmill is moving underneath is completely irrelevant.

The question states the the treadmill moves in the opposite direction at the same rate of speed at the which the planes moves forward. This keeps the plane from moving forward. The plane can obtain lift because the prop is directing air over the wings. If you don't believe me look it up yourself, there's no debating it.