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Speed,Combat,Scale,Racing => Scale Models => Topic started by: bob werle on July 24, 2008, 11:40:20 PM

Title: Bell L-39
Post by: bob werle on July 24, 2008, 11:40:20 PM

I am starting to gather material for a scale project that I hope will be different.  Bell modified 2  P-63 kingcobra aircraft to test the Gearman swept wing data that we recovered an the end of the war.  I think a swept wing P-63 would look great.  My only problem is the only 3-view I can find is for the 1/2 scale wind tunnel test model.  Will this be acceptable in my documentation?

Title: Re: Bell L-39
Post by: chuck snyder on July 25, 2008, 04:18:30 PM

I doubt any of us on this forum can give a definitive answer--it would be up to the contest director at a meet and subject to a protest. I'll offer some "devil's advocate" thoughts however. The rules say your model must be of a man-carrying airplane that actually flew. If you present the drawings of a wind tunnel model a protestor (or the CD) could say that you replicated that, not a man carrying airplane.

Do you have other photographic information? Do you have color and markings information? With enough photos you could modify the wind tunnel model drawings (assuming it was not reproportioned for Reynold's number adjustments) and have a scale contest board member certify them. Then they are definitely usable.

Chuck

Title: Re: Bell L-39
Post by: bob werle on July 25, 2008, 06:52:54 PM

Thank you.  I do have photoe and color information.

Title: Re: Bell L-39
Post by: Chris McMillin on July 25, 2008, 08:52:02 PM

Hi Bob,
I found this site, cool side view.
Chris...

http://www.letletlet-warplanes.com/2008/05/30/bell-l-39-sweep-cobra/

Title: Re: Bell L-39
Post by: bob werle on July 25, 2008, 10:22:43 PM

I had found that site.  This just has to be modeled.  It just too different not to be made.

Title: Re: Bell L-39
Post by: Chris McMillin on July 25, 2008, 11:57:49 PM

Bob,
There are 15 good B&W pics of the two swept wing birds in Birch Matthews "Cobra, Bell Aircraft Corporation 1934-1946", Schiffer Military History publications. No three views though.
One note about the airplane is that the main landing gear did not retract on the swept wing test aircraft.
Chris...

Title: Re: Bell L-39
Post by: Thomas Wilk on July 26, 2008, 08:12:59 AM

some photos

Title: Re: Bell L-39
Post by: Chris McMillin on July 26, 2008, 10:41:48 AM

I like the one with no slats and small wing better.
Chris...

Title: Re: Bell L-39
Post by: bob werle on July 26, 2008, 10:20:25 PM

I like the one with the straight sweep not the one with the small straight section of l/e.  It just a clean looking ship andso different   

Title: Re: Bell L-39
Post by: Just One-eye on July 27, 2008, 01:09:30 PM

Although I don't know the engine mount position in the P-59A, I had already had the thought that a P-39 / P-63 was an excellent choice for the preliminary testing because of the rearward mount of the Allison in the two Bell fighters.  Changing the MAC toward the rear was going to be a problem for designs with forward mounted engines, becoming hugely nose-heavy. 

Chances are pretty good that the P-59A's engine was enough lighter than the recip usual, that longitudinal balance, whatever it's called in aviation engineering, was a potential problem, and looking at the P-80, it looked like a lot of extra nose sticking out in front of the pilot that wasn't needed, if not to provide additional forward moment arm?

Title: Re: Bell L-39
Post by: Chris McMillin on July 27, 2008, 08:22:09 PM

The P-80 nose mention is interesting.
The T-33 was 30 mph faster because the nose and canopy were longer still!
Chris...

Title: Re: Bell L-39
Post by: Robert McHam on July 28, 2008, 06:06:41 PM

I never knew of this swept wing bird!
Way cool if you ask me.

Quote by Ty:
"Amazing what you scale builders will dig up. Love it."
So true friends!

Has anyone see the drawings of the forward swept wing version of the P-51 Mustang? I am pretty sure not even one was built full scale but what an interesting concept it was. Sure would like to see someone build and fly one of those!

I am looking forward to seeing how this one goes first.

Robert

Title: Re: Bell L-39
Post by: Thomas Wilk on July 29, 2008, 07:49:29 AM

not a swept forward P-51 but another experiment.