Cybermonkey
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Registered: 22nd Sep 02
Location: Sydney, Australia
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quote:
Originally posted by Jules S
Of course it will take off
It has jet engines ffs, the engines produce thrust through the air not the conveyor belt.
The contact between the wheels and road is irrelevant 
are you kidding me?!?!?! the engines provide FORWARD THRUST, much like an engine in a car. the wings produce the lift to get the aircraft AIRBORNE. if the aircraft is stationary, there is no air flowing over the wings, there is no lift generated and the aircraft stays on the conveyor at full thrust but not moving forward. in fact, it would soon overheat
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Paul_J
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Registered: 6th Jun 02
Location: London
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quote:
Originally posted by Cybermonkey
quote:
Originally posted by Paul_J
quote:
Originally posted by gianluigi
where's cybermonkey when you need him 
lol just what I thought Surely if just the engine's were enough to lift the plane without any actual movement forward (to get air under the wings) - then the plane should be able to sit on the run way, apply brakes and full thrust - release brakes and take off straight away. Which doesn't happen.
FLMAO the engines only provide forward motion. even at full power, if the conveyor belt is negating the forward movement, the aircraft is stationary. an aircraft ONLY flies when it has a pressure difference between the upper and lower wing great enough to produce lift. Bernoullis principle
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Cybermonkey
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Registered: 22nd Sep 02
Location: Sydney, Australia
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quote:
Originally posted by Paul_J
I see what jules is saying - the plane would still move forward?
"a conveyor belt that is moving at the same speed as the plane in the opposite direction"
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Cybermonkey
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Registered: 22nd Sep 02
Location: Sydney, Australia
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quote:
Originally posted by Paul_J
quote:
Originally posted by Cybermonkey
quote:
Originally posted by Paul_J
quote:
Originally posted by gianluigi
where's cybermonkey when you need him
lol just what I thought Surely if just the engine's were enough to lift the plane without any actual movement forward (to get air under the wings) - then the plane should be able to sit on the run way, apply brakes and full thrust - release brakes and take off straight away. Which doesn't happen.
FLMAO the engines only provide forward motion. even at full power, if the conveyor belt is negating the forward movement, the aircraft is stationary. an aircraft ONLY flies when it has a pressure difference between the upper and lower wing great enough to produce lift. Bernoullis principle
sorry Paul 
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PaulW
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Registered: 26th Jan 03
Location: Atherton, Greater Manchester
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yes it would take off, the aircraft produces thrust via the engines ON THE WING, and NOT via the wheels.
Therefor, if there is a conveyor belt going in the opposite direction while the plane is taking off, and it is doing a normal takeoff routine and such, it just means the wheels will be spinning twice as fast, but the plane will still move forwards as if there is no conveyor.
cant believe people say it wont take off because of the conveyor belt
THE PLANE IS NOT POWERED BY ENGINES RUNNING THE WHEELS FFS BUT INFACT ENGINES ON THE WINGS
wheel speed or conveyors and shit are irrelevant in this situation.
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Angie
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Registered: 27th May 04
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quote:
Originally posted by PaulW
yes it would take off, the aircraft produces thrust via the engines ON THE WING, and NOT via the wheels.
Therefor, if there is a conveyor belt going in the opposite direction while the plane is taking off, and it is doing a normal takeoff routine and such, it just means the wheels will be spinning twice as fast, but the plane will still move forwards as if there is no conveyor.
cant believe people say it wont take off because of the conveyor belt
THE PLANE IS NOT POWERED BY ENGINES RUNNING THE WHEELS FFS BUT INFACT ENGINES ON THE WINGS
wheel speed or conveyors and shit are irrelevant in this situation.
What he said
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Paul_J
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Registered: 6th Jun 02
Location: London
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quote:
Originally posted by PaulW
THE PLANE IS NOT POWERED BY ENGINES RUNNING THE WHEELS FFS BUT INFACT ENGINES ON THE WINGS
I think everyone knows that, however the question was misleading in the way that it sounded like it was going to hold the plane in a stationary position thus it would have no lift under the wings.
I'd have to see it to believe it, as although the 'wheels' would just roll backwards, I think it'd still apply some backward force on the plane, which would slow its take off - if it doesn't get enough speed it still won't lift.
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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yes it will take off
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gianluigi
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Registered: 9th Mar 05
Location: Ipswich, Suffolk
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YOU HAVE NO IDEA ABOUT AVIATIONOLOMOFLI 
THE PLANE WILL TAKE OFF, HAS NOTHING TO DO WITH THE WHEELS, ONCE IT STARTS FLAPPING ITS WINGS IT WILL GO IN THE AIR - LIKE A BIRD FFS
LOOK MUNKY I NO MOOR FIZICS DAN YOO!!!
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PaulW
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Registered: 26th Jan 03
Location: Atherton, Greater Manchester
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very true paul, but still if the engine produces enough thrust, the only negative factor will be the resistance within the wheels themselves, the plane will still move forward at a controlled speed just as if there was not conveyor belt
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Cybermonkey
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Registered: 22nd Sep 02
Location: Sydney, Australia
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quote:
Originally posted by PaulW
very true paul, but still if the engine produces enough thrust, the only negative factor will be the resistance within the wheels themselves, the plane will still move forward at a controlled speed just as if there was not conveyor belt
no IT WONT!!! the aircraft will remain STATIONARY
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gianluigi
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Registered: 9th Mar 05
Location: Ipswich, Suffolk
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[serious] when you are running on a tread mill, you can not feel any wind reistance against you, therefore you are running in one spot[/serious]
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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http://www.newton.dep.anl.gov/askasci/phy05/phy05023.htm
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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"Yes, the plane can take off. The key is that the plane's wheels
*freewheel*, they are not driven. the conveyor belt therefore provides
NO force to the plane (OK, there's a little friction in the bearings
which could provide a couple of pounds force to a nomal GA category
airplane, but that's insignificant compared to the thrust. For an RC
plane, the situation should be similar). The prop pushes the plane
through the air until it reaches takeoff AIRspeed, which is the same no
matter how fast the wheels are going. So if you were inside watching
the instruments, you would observe that the wheels are spinning at a
GROUNDspeed different than the indicated AIRspeed, but that does not
matter, since it is AIRspeed you need in order to take off. (Caps
added for emphasis)."
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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"The only thing that matters is the motion of the wings through the
air. This is what develops lift. The force pulling the plane
forward is developed by the propeller's motion in the air and has
little to do with the wheels or the runway. Since the plane still
moves forward (due to the force of the propeller against the air) it
will still accelerate to the speed required for takeoff. When it
leaves the ground the wheels will not be rotating but otherwise it
will be a perfectly normal takeoff."
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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It obvious, the force is being applied through the engines or the propeller, not the wheels, the conveyor belt would only counteract force applied through the wheels, the is no direct link between force generated through the jets or propeller and the force being applied by the conveyor
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Cybermonkey
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Registered: 22nd Sep 02
Location: Sydney, Australia
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STEVEN THE CONVEYOR BELT MATCHES THE AIRCRAFTS SPEED AT ALL TIMES!! IT IS STATIONARY!!!
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Steve
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Registered: 30th Mar 02
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only if the plane is being propelled by the wheels, your thoughts are matched to much towards say a car trying to drive down the runway
[Edited on 23-05-2006 by Steve]
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Paul_J
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Registered: 6th Jun 02
Location: London
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I think most people know that steve, the difference is on that site it said
quote:
The conveyer belt is designed to exactly
match the speed of the wheels at any given time, moving in the
opposite direction of rotation.
where brads question said
quote:
If an aeroplane is taking off but is on a conveyor belt that is moving at the same speed as the plane in the opposite direction, would the plane take off?
this gave the impression that the plane would be completely stationary - hence people said no lift as no movement.
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Cybermonkey
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Registered: 22nd Sep 02
Location: Sydney, Australia
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no steven NO NO NO. there is no airflow over the wings, the aircraft is not moving through the air no matter how much thrust is pushing the aircraft forward, the aircraft will remain in the same place, upon the conveyor, with its wheels spinning round frantically. no lift forces are being generated since air flow over the wings is 0 KNOTS. you of all people should know this.
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gianluigi
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Registered: 9th Mar 05
Location: Ipswich, Suffolk
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note my "serious" post
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Cybermonkey
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Registered: 22nd Sep 02
Location: Sydney, Australia
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gian that is the perfect definition. thankyou 
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gianluigi
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Registered: 9th Mar 05
Location: Ipswich, Suffolk
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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i know that if the plane would not move it would not lift, but the plane would move.
force requires energy, and also requires opposite energy to counteract something.
Think of it this way, push a toy car along a treadmill your arm will still move at the same rate and use the same amount of force to get it to the end as it would if the car were on a solid surface
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Cybermonkey
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Registered: 22nd Sep 02
Location: Sydney, Australia
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why would the plane move??? it sitting on a moving solid surface which is matching its speed. if the "conveyor" trick works, why dont they use it to launch off aircraft carriers and the such??
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