162 replies to this topic

[wyoairbus]

dolbinau, on Jan 1 2007, 03:00 AM, said:

The conveyor belt is the same length as the runway. It has already been mentioned. There is a huge difference between walking up an escalator and flying an aircraft. We walk relative to the ground. Aircraft fly relative to the air.

Let's use your example of a person on a treadmill.

Say there was a person on a treadmill riding a skateboard, the treadmill is moving very fast however the person is going no where, the wheels are just spinning. Now someone gets a rope and pulls them along, it doesn't matter how fast the conveyor is going the person can still pull them forward, the wheels just move faster. Same situation with the aircraft.

Quote

This is like saying that a seaplane wouldn't take off in a current against it.

Great example.

What you are explaining is that a plane can takeoff on a conveyorbelt the exact size of a runway, given the belt is not moving as fast or faster than the plane's engines can propel it

That is true, so long as the belt is not moving at the same speed or faster than the plane. If the plane is propeling itself faster than the conveyor belt therefore the conveyor belt isnt cancelling out the speed of the plane.


A seaplane will takeoff in a current agaisnt it given the current is not moving as fast or faster than the seaplane's engines can propel it.

Very simple stuff.

[wyoairbus]

Penguin., on Jan 1 2007, 03:14 AM, said:

Yeah smartass, I have a treadmill, and I've launched planes off of it. That's how it know it's true.

Good for you, you launched a plane off a treadmill!

who cares.

Is this the "test" you were talking about?


Was the treadmill moving as fast as the plane's engines could propel it?

I don't think so. If the plane were to gain any speed the treadmill would not have been going as fast as the plane's engines could propel it.\, therfore not canceling the speed and allowing your plane to launch.

You would have to do a bit of work to get your treadmill going exactly the same speed as your plane would go.

Edited by wyoairbus, 01 January 2007 - 03:23 AM.

[Penguin.]

No, it works because the treadmill can't stop it. It works because the wheels are freewheeling. It works because Newton's Law of Motion says so.

It works because you don't understand simple physics. That's why it works!

[wyoairbus]

Penguin., on Jan 1 2007, 03:23 AM, said:

No, it works because the treadmill can't stop it. It works because the wheels are freewheeling. It works because Newton's Law of Motion says so.

It works because you don't understand simple physics. That's why it works!

The treadmill can't stop what?  the thrust of the plane? It can indeed, if it is going exactly the same speed as your plane was.


say your plane could go (for example) 15 mph.

So you put your plane on the treadmill.

You get the treadmill going to Exactly 15 mph. and also get your plane going full throttle (15 mph)

What happens? The plane is stationary on the treadmill becuase it is not moving as fast as the "ground" below it.
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Of Course the Wheels are freewheeling, they cant do anything else. The wheels have no power. instead all the power is coming from the engine moving the aircraft forward.
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Would you mind explaining Newton's Law of Motion and how it applies to this? According to Newton, it should be the opposite of what you are saying.
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I think it is you that doesnt understand simple physics. You believed if the aircraft was stationary on a moving treadmill it would remain stationary!

[Penguin.]

You're wrongly applying the laws set forth by Newton.

Newtons says that for every force, there's an equal and opposite reaction.

For the air from the engines (thrust) the airframe wants to move forwards.

For the motion from the conveyor belt backwards, the free-moving wheels want to turn forwards.

Couple the two together, and you have an airframe that will take off with the wheels turning twice their normal speed.

[dolbinau]

http://www.straightd...mns/060203.html

[Penguin.]

Beautiful dolbinau, beautiful.

[wyoairbus]

If we just keep this up we are going to get no where. My mind is set that I do not belive that a plane will take off on a treadmill going the exact same speed, so that the sircraft is staying in the exact same spot and not moving; you believe it will takeoff.


Reading through this fourm i've heard 89-LX made a video about this thing. I'd like to watch it and see if it disproves exactly what i am saying. until then im not going to continue this back and forth ######

[Penguin.]

Yeah, 89-LX did, and it proved exactly what we've been saying.

[wyoairbus]

thanks for the article, Dolbinau, it explained what i thought was different. according to it, you could pretend the wheels arn't even attached to the aircraft at all, for you don't need them to power anything. The airplane by its own power would still go forward becuase it doesnt push on the ground but rather the air. The wheels just keep it on the ground.



My apologies dolbinau, Peguin., as much as i hate to say it you are right and i am worng

Thats all for me tonight --- getting proved wrong wears you out

[Penguin.]

Bravo for being straight enough to say that. Cheers & Happy 2007.

Edited by Penguin., 01 January 2007 - 04:27 AM.

[wyoairbus]

Penguin., on Jan 1 2007, 04:07 AM, said:

Cheers & Happy 2007.

Same to you, Have a very good new year!

[F16-USAF]

yeahh didn't mean to get into a big debate, i wasnt thinking it through enough and i did admit im wrong

Now lets say there is a 300mph headwind when taking off from a runway will a 737 do a VTO?  

[Flying_Scotsman]

F16-USAF, on Jan 1 2007, 04:48 AM, said:

yeahh didn't mean to get into a big debate, i wasnt thinking it through enough and i did admit im wrong

Now lets say there is a 300mph headwind when taking off from a runway will a 737 do a VTO?  

Yes it will, I you can put it into FS9 weather and have a lot of fun flying around vertically  

[Liam.]

I'm now taking bets for when this topic will appear again!

[89-LX]

Ahhhhhh, not this again.

[N3123V]

NOW PIN THIS ###### THREAD FOR ALL THE FUTURE N00BS!

[Chief_Bean]

N3123V, on Jan 1 2007, 06:10 PM, said:

NOW PIN THIS ###### THREAD FOR ALL THE FUTURE N00BS!

And in answer to the person who asked "When will this thread appear again?" The answer is: The next time another n00b joins

[N3123V]

Chief_Bean, on Jan 1 2007, 01:17 PM, said:

And in answer to the person who asked "When will this thread appear again?" The answer is: The next time another n00b joins

Same with that "Would you be able to land a 747 if the pilots pass out?" question.

[Chief_Bean]

N3123V, on Jan 1 2007, 06:45 PM, said:

Chief_Bean, on Jan 1 2007, 01:17 PM, said:

And in answer to the person who asked "When will this thread appear again?" The answer is: The next time another n00b joins

Same with that "Would you be able to land a 747 if the pilots pass out?" question.

Ugh, that crops up so many times i've lost track of it. And that's only in the short space i've been a member

The typical response from a typical n00b: "Of course I'd be able to, I can land the default 747 in FS2002 Professional, why not in real life? I mean it's FS2002 PROFESSIONAL for God's sake "

Edited by Chief_Bean, 01 January 2007 - 01:49 PM.