PA-12 leading edge supports

[uaweasel]

I'm just about to start assembling a PA-12 wing using Univair stamped ribs and leading edge skins. The original wing feature U and L shaped supports under the leading edge skin, I'm assuming to keep the nose section of the ribs spaced evenly. My question is is it necessary to reinstall these supports when using the Univair ribs and skins? They seem beefier and stiffer than the original Piper ribs. They're pretty beat up and will probably have to make new ones since I can't find them in any catalog - Univair, Dakota, or Wag-Aero.

PW

 

[mike mcs repair]

junk, throw them away

 

[Southern Aero]

PW

I would put them in even if I had to remake them. They provide additional support for the LE skin between the ribs.

 

[Gordon Misch]

I think the original Piper leading edge skins were relatively thin and soft (annealed) aluminum. The new replacement skins are thicker and heat treated, so that those channel supports are unnecessary. I did not use them on my leading edges and have experienced no problems with leading edge deformation. I agree with Mike mcs.

 

[mike mcs repair]

PW

I would put them in even if I had to remake them. They provide additional support for the LE skin between the ribs.

not needed anymore with 2024-T3 LE skins... some of that(old designation) -T3 **** back then was REALLY SOFT.. compared to what the modern stuff is....

 

[Steve Pierce]

Univair still makes them. Look at the outboard lleading edge skin installation in the PA18, 20 or 22. The early skins were 3003 soft aluminum and the reinforcement was installed. When the part numbers changed and the aluminum was 2024-T3 the reinforcement was eliminated. I have a bunch of them stashed behind my sheet metal break because I am a pack rat. Don't know that I will ever use it.

 

[Southern Aero]

not needed anymore with 2024-T3 LE skins... some of that(old designation) -T3 **** back then was REALLY SOFT.. compared to what the modern stuff is....

Oh I agree really not needed with the 2024. But I still put them in especially in the wide rib spacing areas like on a Cub or 12. Seems to help oil canning on a hot sunny day especially if wing is painted a dark color. A whole wings worth doesn't weight a half pound.......... Just another problem with getting old........... just cant let go of the old ways! Hell, I still gas weld ...

 

[kevin]

I had the same question when I was going thru my wings. I asked Clyde Smith Jr. about these. He said that I did not need them so I left them off.

 

[uaweasel]

Thank you all for the input! I'm going to check with my buddy at the FAA to see if I need field approval to leave them off since they're called for on the wing plans. Sure saves me a big headache leaving them off.

PW

 

[uaweasel]

Thanks Mike. I've been going over the photo's you postes on your picasaweb site of the PA-12 restoration. Wish I could just send my stuff to you but Hawaii is a long way from Alaska!