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Post by wizer on Jan 7, 2008 18:49:23 GMT -5
This question has been posted elsewhere around the internet. Apparently it has been around for a while, and tends to generate quite a debate. I have thoroughly researched the matter, and I have drawn my own conclusions, which I believe are accurate beyond the shadow of a doubt.
What's your opinion? Inquiring minds want to know.
Imagine a plane is sitting on a massive conveyor belt, as wide and as long as a runway. The conveyer belt is designed to exactly match the speed of the wheels, moving in the opposite direction. Can the plane take off?
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Post by goods on Jan 7, 2008 18:50:29 GMT -5
If there is no air flowing over the wings the plane will not take off.
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Post by Phyxius on Jan 7, 2008 18:53:50 GMT -5
If there is no air flowing over the wings the plane will not take off. What he said. No airflow = no lift. Aerodynamics 101... |
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Post by bobfromacctg on Jan 7, 2008 22:41:16 GMT -5
If there is no air flowing over the wings the plane will not take off. What he said. No airflow = no lift. Aerodynamics 101... Thats right. Shocking day when I agree when Phyx.. ha. |
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Post by wizer on Jan 8, 2008 10:05:00 GMT -5
Wrong.
There WILL be air flowing over the wings, because the thrust of the jet's engines will propel the plane forward. The thrust does not come from the wheels, which will be free spinning on the treadmill.
The plane will take off, probably even faster then under normal condition because the drag of the wheels on the ground will be greatly reduced.
No worries. Most people get this one wrong.
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Post by goods on Jan 8, 2008 10:07:52 GMT -5
How come when I run on a treadmill I do not feel the wind through my hair.
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Post by goods on Jan 8, 2008 10:09:56 GMT -5
OK you're saying the plane will still move forward... ahhh I see.
So I stand by my statement.... if there is no air flowing over the wings the plane will not take off.
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Post by wizer on Jan 8, 2008 11:43:43 GMT -5
How come when I run on a treadmill I do not feel the wind through my hair. Because when you run on the treadmill, you are not moving forward. You dont move forward because your FEET are what is propelling you forward, and the backwards motion of the treadmill is negating that. An airplane doesnt move forward because of it's "feet" or wheels. If you were on a treadmill with a jet engine strapped to your back, you would feel wind through your hair. I guarantee it. |
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Post by goods on Jan 8, 2008 11:47:14 GMT -5
some just don't get me
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Post by lqdKaos on Jan 8, 2008 13:37:19 GMT -5
OK you're saying the plane will still move forward... ahhh I see. So I stand by my statement.... if there is no air flowing over the wings the plane will not take off. The aircraft will be moving forward, therefore, air will be flowing over the wings. The conveyor belt does not prevent the air from flowing over the wings any more than it prevents forward movement of the aircraft. The only way the conveyor belt would prevent the plane from taking off, is if the wheels produced enough drag to prevent forward movement of the aircraft. The engines of the aircraft produce thrust which is what propels the craft forward producing airflow over the wing. The wheels are on the aircraft soley to allow the craft to move on the ground until sufficient airspeed is gained to produce lift. If the conveyor belt analogy were able to prevent the aircraft from taking off, then as soon as the landing gear were raised, the craft would fall from the sky. |
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Post by goods on Jan 8, 2008 13:54:51 GMT -5
Yeah yeah I got it, pay attention.
Air moving over wings plane go up.
Like others, I pictured the plane as stationary, thus no lift.
Hence the reason the OP posed the question I am sure.... It proves how dumb we all are.
AGAIN I will standby my original comment:
And before you freak out...
IN THIS CASE AIR IS FLOWING OVER THE WINGS
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Post by wizer on Jan 8, 2008 13:57:45 GMT -5
And before you freak out... IN THIS CASE AIR IS FLOWING OVER THE WINGS Ok. It's all good. We're in agreement. Except for phyxius, but that's no surprise. |
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Post by rocko on Jan 8, 2008 14:30:10 GMT -5
Yeah yeah I got it, pay attention. Air moving over wings plane go up. Like others, I pictured the plane as stationary, thus no lift. Hence the reason the OP posed the question I am sure.... It proves how dumb we all are. AGAIN I will standby my original comment: And before you freak out... IN THIS CASE AIR IS FLOWING OVER THE WINGS I pictured the plane not moving, but the wheels turning the the treameal like machine, also. so I ditto everything goods said. |
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zeke
New Member
Posts: 13
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Post by zeke on Jan 9, 2008 14:52:26 GMT -5
This is a really stupid debate. The aircraft must be moving laterally through an air mass in order to produce lift. When you are running on a treadmill, do you run into the far wall? No? Why not?
You don't because the lateral movement is a result of an imbalance of forces acting on the aircraft. The thrust of the engines overcome the static drag and friction of the wheels over the runway, forcing the aircraft to roll forward, down the runway, but more importantly, through the air mass.
Now, if the runway were to match the force applied via the engines, like a treadmill, the forces would remain in balance and the aircraft would not roll, just as you don't move laterally through your bedroom when you are playing hamster on your treadmill. The treadmill absorbs the thrust applied.
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zeke
New Member
Posts: 13
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Post by zeke on Jan 9, 2008 14:56:18 GMT -5
This is a really stupid debate. The aircraft must be moving laterally through an air mass in order to produce lift. When you are running on a treadmill, do you run into the far wall? No? Why not? You don't because the lateral movement is a result of an imbalance of forces acting on the aircraft. The thrust of the engines overcome the static drag and friction of the wheels over the runway, forcing the aircraft to roll forward, down the runway, but more importantly, through the air mass. Now, if the runway were to match the force applied via the engines, like a treadmill, the forces would remain in balance and the aircraft would not roll, just as you don't move laterally through your bedroom when you are playing hamster on your treadmill. The treadmill absorbs the thrust applied. For an experiment, turn on your treadmill as fast you can and still stay on it. How much wind is in your face? |
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