You have a plane and a conveyor belt.

[NanoStuff]

The plane increases it's thrust and the wheels begin to rotate. The belt compensates for #1 the forward rotation of the wheels or #2 the forward movement of the plane, as in the belt moves in reverse exactly as fast as condition #1 or #2

And if it matters, it's a nice sunny day and you have good tires, so you get perfect traction on the belt at all times. Your plane also happens to be very powerful and you can give it as much thrust as you like, but the source of thrust is at the back of the plane so it never provides airflow over the wing.

Does the plane take off using #1?
Does the plane take off using #2?

EDITED: There are two interpretations to the question, #1 or #2. It's best you clarify which of the two conditions you have in mind when making your argument. If you're familiar with the original interpretation of the question, it would be #2.

 

[myusername]

BIGTIME

 

[JMWarren]

No it wouldn't since the airspeed would be 0kts.

FYI - If your flying into enough of a headwind and get the plane into slowflight you can actually have a -ve ground speed (fly backwards) while having a positive air speed.

IE Wind Speed > Air Speed = -ve Ground Speed

 

[MercenaryForHire]

R

 

[mugs]

MAKE IT STOP!!!!!!!!!

Yes it will take off, it has been discussed ad infinitum in another thread.

 

[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?

 

[NanoStuff]

Originally posted by: mugs
MAKE IT STOP!!!!!!!!!

Yes it will take off, it has been discussed ad infinitum in another thread.

Actually this is a little different and plenty more precise

 

[imported_bum]

I'd say no. If there is no air flowing over the wings, it won't take off.

 

[Rainsford]

Uh, no...airflow over the wing provides lift...and that requires the plane to be moving...which it wouldn't be doing.

 

[D1gger]

The wheels are not driving the plane forward, the engines are, so the plane moves forward until the air passing over the wings gives it enough lift to take off. The wheels spinning on the conveyor belt have absolutely nothing to do with the physics of a plane flying.

 

[slugg]

yes

 

[myusername]

ugh.

 

[JMWarren]

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?

I see where your comming from, but don't see how it has anything to do with wheel friction. I was wrong initially this would generate an air speed about equal to the speed of the belt.

So yes the plane could take off.

The question is why don't you feel wind in your face when running on a treadmill?

 

[Evadman]

Yes it will take off. Airplanes don't push using wheels, wheels just free roll. As long as the air is not moving at the exact opposite speed as the plane, it will take off. The wheels will just be spinning at exactly double the ground speed of the aircraft.

I hope eveyone who is saying no is just saying so to smite the OP for posting this again.

 

[PurdueRy]

Originally posted by: JMWarren

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?

I see where your comming from, but don't see how it has anything to do with wheel friction. I was wrong initially this would generate an air speed about equal to the speed of the belt.

So yes the plane could take off.

The question is why don't you feel wind in your face when running on a treadmill?

your feet require a friction force

 

[MrDingleDangle]

yes yes yes yes yes yes yes

this has been discussed and shown many times...

http://www.straightdope.com/columns/060203.html

 

[JMWarren]

I'm still not so sure. If the plane isn't moving forward in space there is no air flow over the wings.

Edit: Nevermind, It just dawned on. Just like taking off on water.

 

[Evadman]

Originally posted by: JMWarren
I'm still not so sure. If the plane isn't moving forward in space there is no air flow over the wings.

The point is the plane is moving. the wheels do nothing. The belt moving backwards means nothing, since the plane uses it propeller or jet engine to push against the air not the ground.

Plane != Car

 

[myusername]

Originally posted by: JMWarren
I'm still not so sure. If the plane isn't moving forward in space there is no air flow over the wings.

THAT is correct. Except the plane IS moving forward. Imagine being on a treadmill with roller blades. By hanging onto the sides, you hold yourself constant against the moving conveyor. If you pull yourself forward by your arms, you will move forward against the conveyor belt, even if the conveyor increases in speed. Now, instead of pulling yourself forward by your arms, stick a jet engine on your back.

 

[thirdlegstump]

You people are retarded. It will not take off as the sole lift mechanism (the wings) will not be getting any airflow. The engines only push the aircraft so that enough air can flow over the wings. Only then will the aircraft achieve any level of lift. I'm a private pilot with instrument license.

Now if there is enough headwind, even when the plane is visually stationary, it's possible that the headwind itself can push the plane up a bit but it would be very uncontrolled and will simply flip the plane over.

 

[Evadman]

Originally posted by: deathkoba
You people are retarded. It will not take off as the sole lift mechanism (the wings) will not be getting any airflow. The engines only push the aircraft so that enough air can flow over the wings. Only then will the aircraft achieve any level of lift. I'm a private pilot with instrument license.

Now if there is enough headwind, even when the plane is visually stationary, it's possible that the headwind itself can push the plane up a bit but it would be very uncontrolled and will simply flip the plane over.

Quoted for posterity so we can all laugh later.

 

[myusername]

Originally posted by: deathkoba
I'm a private pilot with instrument license.

Bully for you. NO one is questioning that the plane must be moving to create lift. The only question is whether the plane moves. The answer is yes, and you can figure out why for yourself.

 

[DaiShan]

Originally posted by: myusername
ugh.

agreed, I won't waste my time here either heh.

 

[thirdlegstump]

Originally posted by: myusername

Originally posted by: deathkoba
I'm a private pilot with instrument license.

Bully for you. NO one is questioning that the plane must be moving to create lift. The only question is whether the plane moves. The answer is yes, and you can figure out why for yourself.

No, the question asks whether the plane will take off.

 

[Evadman]

Originally posted by: deathkoba
No, the question asks whether the plane will take off.

Answer: Yes.