Construction of a Light Aircraft

[H80N]

Here is an instructional film of the construction of a Piper J3 Cub during WWII...

Part of it illustrates the fixturing and welding of the Chrome Moly tube fuselage..
the same techniques would apply to a sports racing car chassis... with some adaptation to the TIG welding process.... as opposed to oxy-fuel...

http://www.youtube.com/watch?feature...&v=Q6q1VKsTeKQ

It is instructive to see how effectively things were done some 70 years ago... before hi-tech

This link had been posted on SFT... credit where due and kudos to diggerdoug..

[H80N]

Dynasty 200DX Aircraft Fuselage Welding...

What a difference 70 years makes.... here is a Bearhawk 4130 tube fuselage TIG welded with a Dynasty...

http://www.youtube.com/watch?v=guZCK_0BMqo

this is fairly short but very informative on tube welding technique..... the rest of his videos worth watching as well.....

[kvwall]

Great videos. As a former pilot, I always enjoy instructional videos that include welding and aircraft.

[dandeman]

Early Days of seeing Piper J3 and other chromemoy framed aircraft repairs..

quote from above: "It is instructive to see how effectively things were done some 70 years ago... before hi-tech"

and the skills of those doing the work that were not so obvious to the bystander..

I had an older brother who started working at a local small airport in exchange for flying time.. He was flying at the age of 14 and went on to become a Navy carrier pilot flying the F8 Crusader.

A fringe benefit to me as a young kid was a free run of the place (times were different back then) and I learned alot just from visual observation of engines and aircraft in various states of disassembly and the bone yard out back of one of the hangers of a few aircraft that had crashed or were scrapped out.

This strip was run by an FAA certified A&E mechanic who rebuilt engines, did major repairs to aircraft and that of course got into O/A gas welding of the chromemoly tube frames that a number of aircraft including the Piper J3 were constructed of.

Pieces of chromemoly were cut out of the boneyard scrapped airframes on occasion to make repairs to other aircraft.. Of course it was only in later years I myself learned of the care that must be taken, and post heat treating of chromemoly after the gas welding..

I've have a few photographs from this era and documented some of the memories in this link.. http://home.4x4wire.com/deddleman/se...navy_days.html

[JacksonJerry]

I am not aware of the need to heat treat after gas welding. Can you expound on that statement?

"I myself learned of the care that must be taken, and post heat treating of chromemoly after the gas welding.."

http://home.4x4wire.com/deddleman/se...navy_days.html[/QUOTE]


Jerry Jackson
San Antonio

[H80N]

With what looks like the beginings of a good discussion of oxy-fuel over on the welding forum...

I thought this thread might need a bounce....

http://www.millerwelds.com/resources...Equipment-line

Oxy-Fuel is a versatile method that will always be around...

Heck... if we see one of those doomsday scenarios where tech is destroyed and shield gasses like argon & helium become unobtanium...non-players... electronics is inop or EMP'd

We will still be able to decompose water and weld using Oxy-Hydrogen.... and do a darned respectable job of it in many areas...

[H80N]

Just for Gee Whiz....

Here is link to the latest FAA guidelines on Aircraft Welding...

http://www.faa.gov/regulations_polic...a/ama_Ch05.pdf

Was a good excuse for a BUMP....

[old jupiter]

When, and which company, first started making their light aircraft fuselages of chrome-moly? I thought Cubs and other puddle-jumpers of the early-'40s were NOT chrome-moly . . .

As to post-weld heat-treating of chrome-moly light aircraft structures, Jerry, that is a long-standing source of disagreement. Two on opposite sides were the late tech writer for Sport Aviation magazine, Tony Bingelis, and engineer and FAA welding advisor Richard Finch.

[H80N]

The 31st Annual Sentimental Journey to Cub Haven Fly-In: Tuesday, June 21 - June 25, 2016.

Let's all turn out to celebrate and `` Kiss the ground the Piper J-3 was built on.'' We want to see a beautiful field of yellow, just like the Good Ole Days. Featured plane: The Piper J-3 Cub. As always...we welcome all makes & models.
.

http://www.sentimentaljourneyfly-in.com/



Lock Haven, Pa.

[H80N]

When, and which company, first started making their light aircraft fuselages of chrome-moly? I thought Cubs and other puddle-jumpers of the early-'40s were NOT chrome-moly . . .

As to post-weld heat-treating of chrome-moly light aircraft structures, Jerry, that is a long-standing source of disagreement. Two on opposite sides were the late tech writer for Sport Aviation magazine, Tony Bingelis, and engineer and FAA welding advisor Richard Finch.

Do not know who was first or when....

But do know it was widely accepted and was used in the construction of the RYAN NX-21 "Spirit of St Louis" in 1927
(developed from the Ryan M-1/M2 1926)

http://www.spiritofstlouis2.com/#!th...-aircraft/crha

Although I believe the first aircraft use was much earlier

[Aeronca41]

Sure wish I could attend Sentimental Journey, but not possible.

As to heat treating 4130 assemblies, my two cents worth-there is plenty of disagreement. I am not an A&P, but the old timers, both A&Ps and homebuilders, taught me (back in the 60's) that the reason you use mild steel filler instead of 4130 rod for welding 4130 tubing is to prevent having to heat treat. The hardness of the 4130 weld requires heat treat to prevent cracking. With mild steel, you get something like 80% of the strength of 4130 filler in the finished joint (if my old memory remembers correctly) and no cracking issues. I know many disagree. Always just made sure to cool slowly; no drafts or wind. If you want to call that heat treating, I suppose you could, but seems a stretch. Design must always be well beyond a 20% safety factor, so design knowledge covers the 80% strength concerns. (BTW, I am NOT a fan of MIG welded aircraft structures, especially experimentals.) It would seem that if Bingelis was wrong and Finch was right, there would be thousands of homebuilts falling out of the sky, since almost all EAA members followed Bingelis' books and guidance. If you look at accident statistics for homebuilts, structural failure is WAY down the problem list, and the structural failure statistics also include wood construction.

[H80N]

Sure wish I could attend Sentimental Journey, but not possible.

As to heat treating 4130 assemblies, my two cents worth-there is plenty of disagreement. I am not an A&P, but the old timers, both A&Ps and homebuilders, taught me (back in the 60's) that the reason you use mild steel filler instead of 4130 rod for welding 4130 tubing is to prevent having to heat treat. The hardness of the 4130 weld requires heat treat to prevent cracking. With mild steel, you get something like 80% of the strength of 4130 filler in the finished joint (if my old memory remembers correctly) and no cracking issues. I know many disagree. Always just made sure to cool slowly; no drafts or wind. If you want to call that heat treating, I suppose you could, but seems a stretch. Design must always be well beyond a 20% safety factor, so design knowledge covers the 80% strength concerns. (BTW, I am NOT a fan of MIG welded aircraft structures, especially experimentals.) It would seem that if Bingelis was wrong and Finch was right, there would be thousands of homebuilts falling out of the sky, since almost all EAA members followed Bingelis' books and guidance. If you look at accident statistics for homebuilts, structural failure is WAY down the problem list, and the structural failure statistics also include wood construction.

I agree...

FWIW.... I have seen many TIG welded tubular 4130 motorsports structures (ER70-S2 Filler air cooled no heat treat)

That have been through catastrophic crashes and have not seen failure at or near the weld joints

[Heflin]

What about the flooring?

[H80N]

What about the flooring?

what about it...??... what is your question...??