You have a plane and a conveyor belt.

[WHAMPOM]

Originally posted by: kevinthenerd

Originally posted by: CaptnKirk
For an aircraft to fly, there MUST be airflow over the wings.
The entire function of aerodynamic lift is the pressure differential of that airflow.

I don't care how fast the wheels spin, if the entire vehicle doesn't reach a velocity where the wings can provide lift
there is no mechanism to create the lift.

A wing is a 'passive' machine, it needs the speed of airflow to make it work.

Coefficient of lift

I was asking earlier if engines at extremely high speeds would induce such an air flow.

The answer is yes. But the engine would have to be bigger than the plane. And tethered to it. Kinda like flying a kite with a fan.

 

[kevinthenerd]

Originally posted by: WHAMPOM

Originally posted by: kevinthenerd

Originally posted by: CaptnKirk
For an aircraft to fly, there MUST be airflow over the wings.
The entire function of aerodynamic lift is the pressure differential of that airflow.

I don't care how fast the wheels spin, if the entire vehicle doesn't reach a velocity where the wings can provide lift
there is no mechanism to create the lift.

A wing is a 'passive' machine, it needs the speed of airflow to make it work.

Coefficient of lift

I was asking earlier if engines at extremely high speeds would induce such an air flow.

The answer is yes. But the engine would have to be bigger than the plane. And tethered to it. Kinda like flying a kite with a fan.

If you fly a kite with a fan, the only net force you'll have is due to the mass flux of air. Every bit of force you put against the kite is only going to be pulled the other way against the string tied to the fan (if it's tethered).

I'm asking if there's enough mass flux DOWNWARD in the end to make the plane lift off.

 

[CVSiN]

Originally posted by: myusername

Originally posted by: JMWarren
No it wouldn't since the airspeed would be 0kts.

Yes, it would, because an airplane doesn't require wheel friction to take off. Ever seen a plane on skis or pontoons?

this is a retarded answer...

as someone that spent 10 years in the navy working with aircraft and catapults.
the whole problem is NO AIR OVER THE WINGS.. UNLESS you have enough airflow over the wings the airplane does NOT WORK...

this is why a carrier MUST have 30kts of wind over the deck minimum even with a catapult to get aircraft airborne...

without enough air over and under the wing the aircraft falls into the ocean even with a full power cat shot..

so in this case you would do nothing but move the treadmills thus generating no lift...
UNLESS you had gigantic fans moving air over the wing surface that would EQUAL the aircrafts normal operating pressure for the airfoil to work generating lift.

 

[cKGunslinger]

Originally posted by: wvtalbot
wow you guys put way to much into this.

And you, too little. Good job! :thumbsup:

:roll:

 

[PurdueRy]

Originally posted by: CVSiN

Originally posted by: myusername

Originally posted by: JMWarren
No it wouldn't since the airspeed would be 0kts.

Yes, it would, because an airplane doesn't require wheel friction to take off. Ever seen a plane on skis or pontoons?

this is a retarded answer...

as someone that spent 10 years in the navy working with aircraft and catapults.
the whole problem is NO AIR OVER THE WINGS.. UNLESS you have enough airflow over the wings the airplane does NOT WORK...

this is why a carrier MUST have 30kts of wind over the deck minimum even with a catapult to get aircraft airborne...

without enough air over and under the wing the aircraft falls into the ocean even with a full power cat shot..

so in this case you would do nothing but move the treadmills thus generating no lift...
UNLESS you had gigantic fans moving air over the wing surface that would EQUAL the aircrafts normal operating pressure for the airfoil to work generating lift.

Might wanna check your assessment that the plane can't move on the treadmill...

 

[CVSiN]

Originally posted by: PurdueRy

Originally posted by: CVSiN

Originally posted by: myusername

Originally posted by: JMWarren
No it wouldn't since the airspeed would be 0kts.

Yes, it would, because an airplane doesn't require wheel friction to take off. Ever seen a plane on skis or pontoons?

this is a retarded answer...

as someone that spent 10 years in the navy working with aircraft and catapults.
the whole problem is NO AIR OVER THE WINGS.. UNLESS you have enough airflow over the wings the airplane does NOT WORK...

this is why a carrier MUST have 30kts of wind over the deck minimum even with a catapult to get aircraft airborne...

without enough air over and under the wing the aircraft falls into the ocean even with a full power cat shot..

so in this case you would do nothing but move the treadmills thus generating no lift...
UNLESS you had gigantic fans moving air over the wing surface that would EQUAL the aircrafts normal operating pressure for the airfoil to work generating lift.

Might wanna check your assessment that the plane can't move on the treadmill...

Um if its on a TREADMILL the wheels will spin just like a car on a dyno....
it will never gain forward momentum and if it were to outspin the treadmill it would FALL OFF and crash...

So you lose at the physics..

I swear computer geeks can be dumb sometimes..
the OP stated that the treadmill would keep up with the A/C providing NO DRAG which would mean the aircraft would act like a person on a treadmill stays in 1 place..
the aircraft therfore would NEVER gain wind over the wings therefore the aircraft cannot take off..

end of story.. period it doesnt work period.

 

[JujuFish]

Originally posted by: CVSiN
Um if its on a TREADMILL the wheels will spin just like a car on a dyno....
it will never gain forward momentum and if it were to outspin the treadmill it would FALL OFF and crash...

So you lose at the physics..

I swear computer geeks can be dumb sometimes..
the OP stated that the treadmill would keep up with the A/C providing NO DRAG which would mean the aircraft would act like a person on a treadmill stays in 1 place..
the aircraft therfore would NEVER gain wind over the wings therefore the aircraft cannot take off..

end of story.. period it doesnt work period.

Riiiiiiiight, mmhmm.

 

[mugs]

Originally posted by: CVSiN

Originally posted by: PurdueRy

Originally posted by: CVSiN

Originally posted by: myusername

Originally posted by: JMWarren
No it wouldn't since the airspeed would be 0kts.

Yes, it would, because an airplane doesn't require wheel friction to take off. Ever seen a plane on skis or pontoons?

this is a retarded answer...

as someone that spent 10 years in the navy working with aircraft and catapults.
the whole problem is NO AIR OVER THE WINGS.. UNLESS you have enough airflow over the wings the airplane does NOT WORK...

this is why a carrier MUST have 30kts of wind over the deck minimum even with a catapult to get aircraft airborne...

without enough air over and under the wing the aircraft falls into the ocean even with a full power cat shot..

so in this case you would do nothing but move the treadmills thus generating no lift...
UNLESS you had gigantic fans moving air over the wing surface that would EQUAL the aircrafts normal operating pressure for the airfoil to work generating lift.

Might wanna check your assessment that the plane can't move on the treadmill...

Um if its on a TREADMILL the wheels will spin just like a car on a dyno....
it will never gain forward momentum and if it were to outspin the treadmill it would FALL OFF and crash...

So you lose at the physics..

I swear computer geeks can be dumb sometimes..
the OP stated that the treadmill would keep up with the A/C providing NO DRAG which would mean the aircraft would act like a person on a treadmill stays in 1 place..
the aircraft therfore would NEVER gain wind over the wings therefore the aircraft cannot take off..

end of story.. period it doesnt work period.

Your answers make baby Jesus cry.

The reason the plane can and will move along the treadmill is that its source of propulsion is not the wheels. The wheels are more or less freely rotating (with a little bit of friction). It would be easier to understand if you consider what would happen if you took away the friction in the wheels (but not the friction between tire and treadmill). The treadmill could spin all it wants, and the wheels would spin as well, but the plane would just sit there if it didn't have its engines on. Add a little thrust and it can very easily move. Add the friction back to the wheels and the plane can still move.

 

[Armitage]

Originally posted by: CVSiN

Originally posted by: PurdueRy

Originally posted by: CVSiN

Originally posted by: myusername

Originally posted by: JMWarren
No it wouldn't since the airspeed would be 0kts.

Yes, it would, because an airplane doesn't require wheel friction to take off. Ever seen a plane on skis or pontoons?

this is a retarded answer...

as someone that spent 10 years in the navy working with aircraft and catapults.
the whole problem is NO AIR OVER THE WINGS.. UNLESS you have enough airflow over the wings the airplane does NOT WORK...

this is why a carrier MUST have 30kts of wind over the deck minimum even with a catapult to get aircraft airborne...

without enough air over and under the wing the aircraft falls into the ocean even with a full power cat shot..

so in this case you would do nothing but move the treadmills thus generating no lift...
UNLESS you had gigantic fans moving air over the wing surface that would EQUAL the aircrafts normal operating pressure for the airfoil to work generating lift.

Might wanna check your assessment that the plane can't move on the treadmill...

Um if its on a TREADMILL the wheels will spin just like a car on a dyno....
it will never gain forward momentum and if it were to outspin the treadmill it would FALL OFF and crash...

So you lose at the physics..

I swear computer geeks can be dumb sometimes..
the OP stated that the treadmill would keep up with the A/C providing NO DRAG which would mean the aircraft would act like a person on a treadmill stays in 1 place..
the aircraft therfore would NEVER gain wind over the wings therefore the aircraft cannot take off..

end of story.. period it doesnt work period.

For somebody that has spent 10 years working with aircraft, you have remarkly little insight into how they actually move. Here's a hint - your car on a dyno analogy has absolutely nothing in common with an aircraft on a treadmill.

 

[Kev]

This thread actually makes me angry at this point. THE PLANE TAKES OFF. IT IS NOT THAT DIFFICULT TO COMPREHEND.

 

[PurdueRy]

Originally posted by: CVSiN

Originally posted by: PurdueRy

Originally posted by: CVSiN

Originally posted by: myusername

Originally posted by: JMWarren
No it wouldn't since the airspeed would be 0kts.

Yes, it would, because an airplane doesn't require wheel friction to take off. Ever seen a plane on skis or pontoons?

this is a retarded answer...

as someone that spent 10 years in the navy working with aircraft and catapults.
the whole problem is NO AIR OVER THE WINGS.. UNLESS you have enough airflow over the wings the airplane does NOT WORK...

this is why a carrier MUST have 30kts of wind over the deck minimum even with a catapult to get aircraft airborne...

without enough air over and under the wing the aircraft falls into the ocean even with a full power cat shot..

so in this case you would do nothing but move the treadmills thus generating no lift...
UNLESS you had gigantic fans moving air over the wing surface that would EQUAL the aircrafts normal operating pressure for the airfoil to work generating lift.

Might wanna check your assessment that the plane can't move on the treadmill...

Um if its on a TREADMILL the wheels will spin just like a car on a dyno....
it will never gain forward momentum and if it were to outspin the treadmill it would FALL OFF and crash...

So you lose at the physics..

I swear computer geeks can be dumb sometimes..
the OP stated that the treadmill would keep up with the A/C providing NO DRAG which would mean the aircraft would act like a person on a treadmill stays in 1 place..
the aircraft therfore would NEVER gain wind over the wings therefore the aircraft cannot take off..

end of story.. period it doesnt work period.

BAHAHAHAHAHA! OF COURSE I lose at physics. I have only provided 2 or three practical examples in this thread of ways to demonstrate why the plane can move forward on the treadmill....explained why the FBD shows it can accelerate, and shown why the FBD in those examples exactly reflects the FBD for this plane/conveyor case. But you're right, I lose.

If you are interested in actually looking at the physics of this. Draw the FBD...don't just reply saying I am wrong, DRAW THE FBD. You will see a force acting on the plane by the engines this force is UNOPPOSED.

you might say "BUT BUT BUT TEH TREADMILLZ MOVz its BaKwards!?!?!!!!!!one!11"

Now look at the force the treadmill applies....it acts on the wheels...sure. But how does that force cancel the thrust from the engines? It CANNOT. The force can only spin the wheels faster...it cannot cancel the force therefore the unopposed force causes a constant acceleration until the plane takes off.

 

[JujuFish]

Creeping in on 1,000 posts... I wonder if anyone who argues that the plane does not take off has actually read the thread.

 

[sao123]

The hot water freezes first...

but will the cold water boil first???

 

[CaptnKirk]

Originally posted by: kevinthenerd

I'm asking if there's enough mass flux DOWNWARD in the end to make the plane lift off.

Airflow DOWNWARD has nothing to do with how a wing generates lift.

When air encounters the leading edge of a wing at the STAGNATION POINT, the airflow separates into the flow over the top, and the flow under the wing.
The way that a wing is designed is so the flow over the upper surface (top) has a longer path to travel before it reaches the trailing edge of the wing than the flow path under the wing.

The longer path demands that the airflow must accelerate over the upper surface to rejoin at the back with the original air mass.
High speed air is lower pressure air, so a low pressure area is generated by the upper wing surface, relative to the higher pressure underneath.
The wing moves upward into the low pressure area according to the surface area swept by the moving air mass,
and dependant on the Pressure Difference between the two surfaces.

Most of the lift of a wing, 75% - 80% is generated buy the low pressure on the wings top surface, only 20% 25% of the lifting moment is caused by
the higher relative pressure below the wing, except when it comes into the 'Ground Effects' zone -
a cusion area that is underneath the wing that is roughly equivalent to the total span of the wing structure.
Not only does ground effects add a slight lifting boost to the wing, it also reduces the drag by a small amount.

Downwash airflow from a wing does not add to a wings lift or help the wing fly. It is a result of the drag component of the wing,
and moves down because of the deflection of the airflow behind the wing.

 

[cKGunslinger]

Originally posted by: CVSiN

Um if its on a TREADMILL the wheels will spin just like a car on a dyno....
it will never gain forward momentum and if it were to outspin the treadmill it would FALL OFF and crash...

So you lose at the physics..

I swear computer geeks can be dumb sometimes..
the OP stated that the treadmill would keep up with the A/C providing NO DRAG which would mean the aircraft would act like a person on a treadmill stays in 1 place..
the aircraft therfore would NEVER gain wind over the wings therefore the aircraft cannot take off..

end of story.. period it doesnt work period.

Sorry, CV, not true. There are many, many examples in these threads that can help you visualize that the plane can move on a treadmill.

One is the thought of you in a pair of rollerskates on a treadmill, holding onto a rope that is attached to the wall in front of you. Now, do you think you have to pull yourself forward with the rope as fast as the treadmill is rolling just to remain stationary? Or do your wheels roll freely and pulling yourself forward lets you move from the rear of the treadmill to the front with relatively little effort?

Think about it. The force of your pulling on the rope is the same as the force of the jet's engine on the plane. It is mostly independent of the wheels and can easily act on the body of the plane, just as your arms and the rope can act on you, regardless of the treadmill and your skates. Assuming you have a good center of balance and high-quality wheels and bearings, you can increase the speed of the treadmill to almost arbitrary speeds (200+mph) and you can still pull yourself forward (relative to you surroundings) with the same effort.


Ergo, the plane can move and generate lift. It is *nothing* like a car on a dyno.


edit: Get Valk in some short shorts, tank top, pig-tails, and old-fashioned rollerskates and put her on treadmill. Place your hands on her ass and gently push her forward as the treadmill is moving. Take lots of pics and post them here.

 

[dawks]

Originally posted by: CVSiN

Originally posted by: PurdueRy

Originally posted by: CVSiN

Originally posted by: myusername

Originally posted by: JMWarren
No it wouldn't since the airspeed would be 0kts.

Yes, it would, because an airplane doesn't require wheel friction to take off. Ever seen a plane on skis or pontoons?

this is a retarded answer...

as someone that spent 10 years in the navy working with aircraft and catapults.
the whole problem is NO AIR OVER THE WINGS.. UNLESS you have enough airflow over the wings the airplane does NOT WORK...

this is why a carrier MUST have 30kts of wind over the deck minimum even with a catapult to get aircraft airborne...

without enough air over and under the wing the aircraft falls into the ocean even with a full power cat shot..

so in this case you would do nothing but move the treadmills thus generating no lift...
UNLESS you had gigantic fans moving air over the wing surface that would EQUAL the aircrafts normal operating pressure for the airfoil to work generating lift.

Might wanna check your assessment that the plane can't move on the treadmill...

Um if its on a TREADMILL the wheels will spin just like a car on a dyno....
it will never gain forward momentum and if it were to outspin the treadmill it would FALL OFF and crash...

So you lose at the physics..

I swear computer geeks can be dumb sometimes..
the OP stated that the treadmill would keep up with the A/C providing NO DRAG which would mean the aircraft would act like a person on a treadmill stays in 1 place..
the aircraft therfore would NEVER gain wind over the wings therefore the aircraft cannot take off..

end of story.. period it doesnt work period.

Dude you are so wrong. The whole key to this is the wheels are relatively free spinning. With the exception of the initial rolling resistance (which is very easily over come by the turbofan engines), and a small amount of bearing resistance.

If you set the aircraft on a runway sized conveyor, and just tied the front of the plane to a wall or post with a rope at the front of the belt, you can speed up with belt as much as you like, and the resistance on that rope will hardly increase at all, because the wheels are relatively free spinning. The belt speeds up, the wheels speed up.

Now if you started pulling on that rope, the plane would move forward, even if you sped up the belt, because the wheels could automatically increase their speed in the opposite direction, to compensate. The plane would move forward.

Now use a turbo-fan engine to provide thrust to move the aircraft forward, even if the belt speeds up, the wheels will simply compensate by spinning faster in the opposing direction. The plane will move forward through the air, and at V2, the aircraft will lift off.

My first reaction to this question was a resounding 'no' also, but after reading some posts, and actually thinking about it, its very clear the aircraft will take off. The fact that the wheels are free spinning, and do not provide any thrust for the aircraft negates any effect a conveyor or treadmill will have on the takeoff proceedure.

Its odd that a 'computer nerd' understands aircrafts better then an 10 year aircraft carrier deck hand verteran.

 

[dawks]

Originally posted by: cKGunslinger

Originally posted by: CVSiN

Um if its on a TREADMILL the wheels will spin just like a car on a dyno....
it will never gain forward momentum and if it were to outspin the treadmill it would FALL OFF and crash...

So you lose at the physics..

I swear computer geeks can be dumb sometimes..
the OP stated that the treadmill would keep up with the A/C providing NO DRAG which would mean the aircraft would act like a person on a treadmill stays in 1 place..
the aircraft therfore would NEVER gain wind over the wings therefore the aircraft cannot take off..

end of story.. period it doesnt work period.

Sorry, CV, not true. There are many, many examples in these threads that can help you visualize that the plane can move on a treadmill.

One is the thought of you in a pair of rollerskates on a treadmill, holding onto a rope that is attached to the wall in front of you. Now, do you think you have to pull yourself forward with the rope as fast as the treadmill is rolling just to remain stationary? Or do your wheels roll freely and pulling yourself forward lets you move from the rear of the treadmill to the front with relatively little effort?

Think about it. The force of your pulling on the rope is the same as the force of the jet's engine on the plane. It is mostly independent of the wheels and can easily act on the body of the plane, just as your arms and the rope can act on you, regardless of the treadmill and your skates. Assuming you have a good center of balance and high-quality wheels and bearings, you can increase the speed of the treadmill to almost arbitrary speeds (200+mph) and you can still pull yourself forward (relative to you surroundings) with the same effort.


Ergo, the plane can move and generate lift. It is *nothing* like a car on a dyno.


edit: Get Valk in some short shorts, tank top, pig-tails, and old-fashioned rollerskates and put her on treadmill. Place your hands on her ass and gently push her forward as the treadmill is moving. Take lots of pics and post them here.

w00t, I used that example back at around 500 posts.. I don't think anyone read it

 

[CVSiN]

Originally posted by: dawks

Originally posted by: CVSiN

Originally posted by: PurdueRy

Originally posted by: CVSiN

Originally posted by: myusername

Originally posted by: JMWarren
No it wouldn't since the airspeed would be 0kts.

Yes, it would, because an airplane doesn't require wheel friction to take off. Ever seen a plane on skis or pontoons?

this is a retarded answer...

as someone that spent 10 years in the navy working with aircraft and catapults.
the whole problem is NO AIR OVER THE WINGS.. UNLESS you have enough airflow over the wings the airplane does NOT WORK...

this is why a carrier MUST have 30kts of wind over the deck minimum even with a catapult to get aircraft airborne...

without enough air over and under the wing the aircraft falls into the ocean even with a full power cat shot..

so in this case you would do nothing but move the treadmills thus generating no lift...
UNLESS you had gigantic fans moving air over the wing surface that would EQUAL the aircrafts normal operating pressure for the airfoil to work generating lift.

Might wanna check your assessment that the plane can't move on the treadmill...

Um if its on a TREADMILL the wheels will spin just like a car on a dyno....
it will never gain forward momentum and if it were to outspin the treadmill it would FALL OFF and crash...

So you lose at the physics..

I swear computer geeks can be dumb sometimes..
the OP stated that the treadmill would keep up with the A/C providing NO DRAG which would mean the aircraft would act like a person on a treadmill stays in 1 place..
the aircraft therfore would NEVER gain wind over the wings therefore the aircraft cannot take off..

end of story.. period it doesnt work period.

Dude you are so wrong. The whole key to this is the wheels are relatively free spinning. With the exception of the initial rolling resistance (which is very easily over come by the turbofan engines), and a small amount of bearing resistance.

If you set the aircraft on a runway sized conveyor, and just tied the front of the plane to a wall or post with a rope at the front of the belt, you can speed up with belt as much as you like, and the resistance on that rope will hardly increase at all, because the wheels are relatively free spinning. The belt speeds up, the wheels speed up.

Now if you started pulling on that rope, the plane would move forward, even if you sped up the belt, because the wheels could automatically increase their speed in the opposite direction, to compensate. The plane would move forward.

Now use a turbo-fan engine to provide thrust to move the aircraft forward, even if the belt speeds up, the wheels will simply compensate by spinning faster in the opposing direction. The plane will move forward through the air, and at V2, the aircraft will lift off.

My first reaction to this question was a resounding 'no' also, but after reading some posts, and actually thinking about it, its very clear the aircraft will take off. The fact that the wheels are free spinning, and do not provide any thrust for the aircraft negates any effect a conveyor or treadmill will have on the takeoff proceedure.

Its odd that a 'computer nerd' understands aircrafts better then an 10 year aircraft carrier deck hand verteran.

Dude.. how the hell do you figure..
a treadmill with an F/A-18 sitting on it and thrusting up and its not tied down will try to move forward.. but instead of moving forward the treadmill will move.. so the aircraft will sit idle just like its tied down. no amount of thrust is going to move it off the treadmill.
so how do you get the 150kts of wind under the wings to initiate take off?

 

[JujuFish]

Originally posted by: CVSiN
Dude.. how the hell do you figure..
a treadmill with an F/A-18 sitting on it and thrusting up and its not tied down will try to move forward.. but instead of moving forward the treadmill will move.. so the aircraft will sit idle just like its tied down. no amount of thrust is going to move it off the treadmill.
so how do you get the 150kts of wind under the wings to initiate take off?

The wonderful world of physics. F=ma. The plane has mass m, and a force is being applied by the engines. Since there is a net force, there must be an acceleration. Very simple.

 

[GuitarDaddy]

Originally posted by: CVSiN


Dude.. how the hell do you figure..
a treadmill with an F/A-18 sitting on it and thrusting up and its not tied down will try to move forward.. but instead of moving forward the treadmill will move.. so the aircraft will sit idle just like its tied down. no amount of thrust is going to move it off the treadmill.
so how do you get the 150kts of wind under the wings to initiate take off?

Damn, just damn

Stick to cars and motorcycles, your logic would make sense

 

[PurdueRy]

Originally posted by: CVSiN

Originally posted by: dawks

Originally posted by: CVSiN

Originally posted by: PurdueRy

Originally posted by: CVSiN

Originally posted by: myusername

Originally posted by: JMWarren
No it wouldn't since the airspeed would be 0kts.

Yes, it would, because an airplane doesn't require wheel friction to take off. Ever seen a plane on skis or pontoons?

this is a retarded answer...

as someone that spent 10 years in the navy working with aircraft and catapults.
the whole problem is NO AIR OVER THE WINGS.. UNLESS you have enough airflow over the wings the airplane does NOT WORK...

this is why a carrier MUST have 30kts of wind over the deck minimum even with a catapult to get aircraft airborne...

without enough air over and under the wing the aircraft falls into the ocean even with a full power cat shot..

so in this case you would do nothing but move the treadmills thus generating no lift...
UNLESS you had gigantic fans moving air over the wing surface that would EQUAL the aircrafts normal operating pressure for the airfoil to work generating lift.

Might wanna check your assessment that the plane can't move on the treadmill...

Um if its on a TREADMILL the wheels will spin just like a car on a dyno....
it will never gain forward momentum and if it were to outspin the treadmill it would FALL OFF and crash...

So you lose at the physics..

I swear computer geeks can be dumb sometimes..
the OP stated that the treadmill would keep up with the A/C providing NO DRAG which would mean the aircraft would act like a person on a treadmill stays in 1 place..
the aircraft therfore would NEVER gain wind over the wings therefore the aircraft cannot take off..

end of story.. period it doesnt work period.

Dude you are so wrong. The whole key to this is the wheels are relatively free spinning. With the exception of the initial rolling resistance (which is very easily over come by the turbofan engines), and a small amount of bearing resistance.

If you set the aircraft on a runway sized conveyor, and just tied the front of the plane to a wall or post with a rope at the front of the belt, you can speed up with belt as much as you like, and the resistance on that rope will hardly increase at all, because the wheels are relatively free spinning. The belt speeds up, the wheels speed up.

Now if you started pulling on that rope, the plane would move forward, even if you sped up the belt, because the wheels could automatically increase their speed in the opposite direction, to compensate. The plane would move forward.

Now use a turbo-fan engine to provide thrust to move the aircraft forward, even if the belt speeds up, the wheels will simply compensate by spinning faster in the opposing direction. The plane will move forward through the air, and at V2, the aircraft will lift off.

My first reaction to this question was a resounding 'no' also, but after reading some posts, and actually thinking about it, its very clear the aircraft will take off. The fact that the wheels are free spinning, and do not provide any thrust for the aircraft negates any effect a conveyor or treadmill will have on the takeoff proceedure.

Its odd that a 'computer nerd' understands aircrafts better then an 10 year aircraft carrier deck hand verteran.

Dude.. how the hell do you figure..
a treadmill with an F/A-18 sitting on it and thrusting up and its not tied down will try to move forward.. but instead of moving forward the treadmill will move.. so the aircraft will sit idle just like its tied down. no amount of thrust is going to move it off the treadmill.
so how do you get the 150kts of wind under the wings to initiate take off?

Didn't I JUST explain this in my post????

 

[Armitage]

Originally posted by: CVSiN

Originally posted by: dawks

Originally posted by: CVSiN

Originally posted by: PurdueRy

Originally posted by: CVSiN

Originally posted by: myusername

Originally posted by: JMWarren
No it wouldn't since the airspeed would be 0kts.

Yes, it would, because an airplane doesn't require wheel friction to take off. Ever seen a plane on skis or pontoons?

this is a retarded answer...

as someone that spent 10 years in the navy working with aircraft and catapults.
the whole problem is NO AIR OVER THE WINGS.. UNLESS you have enough airflow over the wings the airplane does NOT WORK...

this is why a carrier MUST have 30kts of wind over the deck minimum even with a catapult to get aircraft airborne...

without enough air over and under the wing the aircraft falls into the ocean even with a full power cat shot..

so in this case you would do nothing but move the treadmills thus generating no lift...
UNLESS you had gigantic fans moving air over the wing surface that would EQUAL the aircrafts normal operating pressure for the airfoil to work generating lift.

Might wanna check your assessment that the plane can't move on the treadmill...

Um if its on a TREADMILL the wheels will spin just like a car on a dyno....
it will never gain forward momentum and if it were to outspin the treadmill it would FALL OFF and crash...

So you lose at the physics..

I swear computer geeks can be dumb sometimes..
the OP stated that the treadmill would keep up with the A/C providing NO DRAG which would mean the aircraft would act like a person on a treadmill stays in 1 place..
the aircraft therfore would NEVER gain wind over the wings therefore the aircraft cannot take off..

end of story.. period it doesnt work period.

Dude you are so wrong. The whole key to this is the wheels are relatively free spinning. With the exception of the initial rolling resistance (which is very easily over come by the turbofan engines), and a small amount of bearing resistance.

If you set the aircraft on a runway sized conveyor, and just tied the front of the plane to a wall or post with a rope at the front of the belt, you can speed up with belt as much as you like, and the resistance on that rope will hardly increase at all, because the wheels are relatively free spinning. The belt speeds up, the wheels speed up.

Now if you started pulling on that rope, the plane would move forward, even if you sped up the belt, because the wheels could automatically increase their speed in the opposite direction, to compensate. The plane would move forward.

Now use a turbo-fan engine to provide thrust to move the aircraft forward, even if the belt speeds up, the wheels will simply compensate by spinning faster in the opposing direction. The plane will move forward through the air, and at V2, the aircraft will lift off.

My first reaction to this question was a resounding 'no' also, but after reading some posts, and actually thinking about it, its very clear the aircraft will take off. The fact that the wheels are free spinning, and do not provide any thrust for the aircraft negates any effect a conveyor or treadmill will have on the takeoff proceedure.

Its odd that a 'computer nerd' understands aircrafts better then an 10 year aircraft carrier deck hand verteran.

Dude.. how the hell do you figure..
a treadmill with an F/A-18 sitting on it and thrusting up and its not tied down will try to move forward.. but instead of moving forward the treadmill will move.. so the aircraft will sit idle just like its tied down. no amount of thrust is going to move it off the treadmill.
so how do you get the 150kts of wind under the wings to initiate take off?

This has got to be a troll. Right? Please tell me this is a troll.

 

[mugs]

Originally posted by: CVSiN
Dude.. how the hell do you figure..
a treadmill with an F/A-18 sitting on it and thrusting up and its not tied down will try to move forward.. but instead of moving forward the treadmill will move.. so the aircraft will sit idle just like its tied down. no amount of thrust is going to move it off the treadmill.
so how do you get the 150kts of wind under the wings to initiate take off?

Here's another simple analogy - suppose you have a FWD car with the rear wheels on the treadmill and the front wheels off the treadmill. Can the car move? Of course. Because the treadmill does not counteract its source of propulsion. Now apply that to the plane - ALL of the wheels freely rotate and the source of propulsion is the turbines which are not in any way affected by the treadmill.

 

[cKGunslinger]

Originally posted by: mugs

Originally posted by: CVSiN
Dude.. how the hell do you figure..
a treadmill with an F/A-18 sitting on it and thrusting up and its not tied down will try to move forward.. but instead of moving forward the treadmill will move.. so the aircraft will sit idle just like its tied down. no amount of thrust is going to move it off the treadmill.
so how do you get the 150kts of wind under the wings to initiate take off?

Here's another simple analogy - suppose you have a FWD car with the rear wheels on the treadmill and the front wheels off the treadmill. Can the car move? Of course. Because the treadmill does not counteract its source of propulsion. Now apply that to the plane - ALL of the wheels freely rotate and the source of propulsion is the turbines which are not in any way affected by the treadmill.

There ya go! Put the front wheel of your bike on the dyno and gun it. Do you sit still? Heck no.

 

[Suspicious-Teach8788]

So how much has your post count shot up because of this thread?