RCCrawler Forums

JeremyH · 01-31-2008, 09:55 AM

Did anyone catch last nights episode? So, did the plane take off?

My guess is no.

procraft98 · 01-31-2008, 10:13 AM

I tivo'd it, but haven't had a chance to watch it yet. I would also assume no, but those guys usually find a way, and if not, they'll just blow it up

!

Mr. Chevy · 01-31-2008, 10:21 AM

BUSTED!!! Plane took off with no problems.

TwistedXT · 01-31-2008, 10:22 AM

i was curious myself.. i doubt it did. with this theory, you would in essance be able to put the plane at full throttle and start to produce lift before forward motion is achieved.. most small aircraft dont do so well under 90mph.. so.. im shooting for no.

JeremyH · 01-31-2008, 10:25 AM

What plane did they use?

JeremyH · 01-31-2008, 10:26 AM

Quote:

Originally Posted by TwistedXT

theory, you would in essance be able to put the plane at full throttle and start to produce lift before forward motion is achieved

The throttle has nothing to do with flight...it just helps the wheels overcome friction with the ground by producing thrust. Hell, grounded planes take off when Hurricanes come through. All you need is a large amount of air passing over and under the wings to create lift.

Mr. Chevy · 01-31-2008, 10:30 AM

Quote:

Originally Posted by JeremyH

What plane did they use?

I am not sure what plane they used but it was just a small single person prop plane.

Mr. Chevy · 01-31-2008, 10:32 AM

Here is a link to the results of there tests.

http://mythbustersresults.com/episode97

JeremyH · 01-31-2008, 10:33 AM

Quote:

Originally Posted by Mr. Chevy

I am not sure what plane they used but it was just a small single person prop plane.

Maybe the external propellor has the ability to send enough air over the wings to create lift. I do not think this could happen with a turbine engine...

Destroyer · 01-31-2008, 10:46 AM

Planes do not use the wheels for propulsion, therefore it does not matter what speed they spin or in what direction. The plane will still move forward, generate lift, and take off.

Example: Conveyor moves at 100mph north. Plane engine moves plane at 100mph south. Wheels spin at 200mph north. Plane still takes off b/c it is moving at 100mph.

JeremyH · 01-31-2008, 10:59 AM

Quote:

Originally Posted by Destroyer

Wheels spin at 200mph north.

If the wheels simply spin (angular velocity) and are not related to the force that moves the plane, then how does the plane move? (whether or not the plane moves when on the conveyor belt is the real question here)

Destroyer · 01-31-2008, 11:12 AM

Its' propeller/ jet engine, which provides thrust against the air. The only effect the conveyor has on the forward speed of the plane is the slight friction from the wheels' bearings (or whatever they spin on).

JeremyH · 01-31-2008, 11:20 AM

Yes. The engine forces the plane to move with respect to the ground, but if the ground is "not moving", then no air will be flowing over/under the wings.

Zardoz · 01-31-2008, 11:23 AM

Well said, definately makes sense. I always thought the myth was that if the conveyor was moving at take off speed and the engine was off then the plane would still take off. Obviously, it wouldn't because there is no air moving past the wings.

Quote:

Originally Posted by Destroyer

Planes do not use the wheels for propulsion, therefore it does not matter what speed they spin or in what direction. The plane will still move forward, generate lift, and take off.

Example: Conveyor moves at 100mph north. Plane engine moves plane at 100mph south. Wheels spin at 200mph north. Plane still takes off b/c it is moving at 100mph.

Destroyer · 01-31-2008, 11:24 AM

There's some good discussion here: http://naxja.org/forum/showthread.php?t=940908

It flys.

CD13 · 01-31-2008, 11:31 AM

Quote:

Originally Posted by Destroyer

Planes do not use the wheels for propulsion, therefore it does not matter what speed they spin or in what direction. The plane will still move forward, generate lift, and take off.

Example: Conveyor moves at 100mph north. Plane engine moves plane at 100mph south. Wheels spin at 200mph north. Plane still takes off b/c it is moving at 100mph.

X2,Well put,Planes use thrust to take off so it doesn't matter what is under them,naval aircraft carriers have been doing it for years but for shorter take off reasons they point the ship into the wind

Rok_Dok · 01-31-2008, 11:38 AM

Love the show....

JeremyH · 01-31-2008, 11:43 AM

Quote:

Originally Posted by JeremyH

Yes. The engine forces the plane to move with respect to the ground, but if the ground is "not moving", then no air will be flowing over/under the wings.

I guess this statement I made is incorrect....the engines force the plane to move with respect to the air...just like a swamp boat...

JamboreeTJ · 01-31-2008, 11:50 AM

I was watching the recap of LOST last night, but I recorded MB. I watched it at 5:00 this morning. Great ep. Aside from being a great myth, I liked the topic because it is easy to come up with the wrong answer and stop thinking about it rather than thinking it through and then deciding that the airplane dynamics are much different than a person walking or car driving on a treadmill.

The "plane" was actually an ultralight single seat aircraft. The scale test with a simple R/C plane was pretty conclusive and a good first-test.

Slickrock450 · 01-31-2008, 12:02 PM

The myth was BUSTED! They used a ultralight style plane. Weight 400 total pounds. Plane w/o conveyor belt took of at a speed of 25mph and took 85 ft to leave runway.

With the conveyor belt moving at 25mph the opposite direction and the plane going the other at 25 mph, the plane took off. It even surprised the pilot. He didn't think that it would take off.

01-31-2008, 09:55 AM	#1
JeremyH I wanna be Dave Join Date: Sep 2005 Location: Houston, TX Posts: 16,952	Mythbusters Episode Did anyone catch last nights episode? So, did the plane take off? My guess is no.

01-31-2008, 10:13 AM	#2
procraft98 Pebble Pounder Join Date: Aug 2007 Location: Broken Arrow, OK Posts: 151	I tivo'd it, but haven't had a chance to watch it yet. I would also assume no, but those guys usually find a way, and if not, they'll just blow it up !

01-31-2008, 10:21 AM	#3
Mr. Chevy Rock Stacker Join Date: Nov 2005 Location: Orem Posts: 71	BUSTED!!! Plane took off with no problems.

01-31-2008, 10:22 AM	#4
TwistedXT Powered by Awesome Join Date: Sep 2004 Location: Parker, Colorado Posts: 3,622	i was curious myself.. i doubt it did. with this theory, you would in essance be able to put the plane at full throttle and start to produce lift before forward motion is achieved.. most small aircraft dont do so well under 90mph.. so.. im shooting for no.

01-31-2008, 10:25 AM	#5
JeremyH I wanna be Dave Join Date: Sep 2005 Location: Houston, TX Posts: 16,952	What plane did they use?

01-31-2008, 10:32 AM	#8
Mr. Chevy Rock Stacker Join Date: Nov 2005 Location: Orem Posts: 71	Here is a link to the results of there tests. http://mythbustersresults.com/episode97

01-31-2008, 10:46 AM	#10
Destroyer Rock Crawler Join Date: Apr 2004 Location: North GA Posts: 824	Planes do not use the wheels for propulsion, therefore it does not matter what speed they spin or in what direction. The plane will still move forward, generate lift, and take off. Example: Conveyor moves at 100mph north. Plane engine moves plane at 100mph south. Wheels spin at 200mph north. Plane still takes off b/c it is moving at 100mph.

01-31-2008, 11:12 AM	#12
Destroyer Rock Crawler Join Date: Apr 2004 Location: North GA Posts: 824	Its' propeller/ jet engine, which provides thrust against the air. The only effect the conveyor has on the forward speed of the plane is the slight friction from the wheels' bearings (or whatever they spin on).

01-31-2008, 11:20 AM	#13
JeremyH I wanna be Dave Join Date: Sep 2005 Location: Houston, TX Posts: 16,952	Yes. The engine forces the plane to move with respect to the ground, but if the ground is "not moving", then no air will be flowing over/under the wings.

01-31-2008, 11:24 AM	#15
Destroyer Rock Crawler Join Date: Apr 2004 Location: North GA Posts: 824	There's some good discussion here: http://naxja.org/forum/showthread.php?t=940908 It flys.

01-31-2008, 11:38 AM	#17
Rok_Dok Pebble Pounder Join Date: Apr 2007 Location: Deer Park Posts: 151	Love the show....

Sponsored Links

01-31-2008, 11:50 AM	#19
JamboreeTJ Rock Stacker Join Date: Dec 2006 Location: Saratoga, NY Posts: 95	I was watching the recap of LOST last night, but I recorded MB. I watched it at 5:00 this morning. Great ep. Aside from being a great myth, I liked the topic because it is easy to come up with the wrong answer and stop thinking about it rather than thinking it through and then deciding that the airplane dynamics are much different than a person walking or car driving on a treadmill. The "plane" was actually an ultralight single seat aircraft. The scale test with a simple R/C plane was pretty conclusive and a good first-test.

01-31-2008, 12:02 PM	#20
Slickrock450 Pebble Pounder Join Date: Aug 2007 Location: Da Springs Posts: 180	The myth was BUSTED! They used a ultralight style plane. Weight 400 total pounds. Plane w/o conveyor belt took of at a speed of 25mph and took 85 ft to leave runway. With the conveyor belt moving at 25mph the opposite direction and the plane going the other at 25 mph, the plane took off. It even surprised the pilot. He didn't think that it would take off.

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