wing rib material

[astjp2]

Does anyone know where and what the original material was used to make the cub style prewar ribs? Univair has a repair kit but where could I find 12' lengths to make new ribs? Tim

[Larry Lyons]

Re: wing rib material

Just talked to Univair this afternoon, 02/18/08, looking for the T-shaped repair mat. for the prewar birds. THEY NO LONGER CARRY THAT RIB REPAIR MATERIAL! Now what? Argh!!!! I may have to make my own yet. I have some old ribs I can cut up but do not know if I will have enough, straight enough.
Larry

[flybikefarm]

Re: wing rib material

If I remember riight someone in the cub club was building a machine to make the t shape material in lengths long enought to make ribs. George

[astjp2]

Re: wing rib material

Its a hat channel, not a T section, you can find a pic in 43.13. You also need to ask for a cub, not a tcraft, same material but most people dont know that. Tim

[Forrest Barber]

Re: wing rib material

Wag - Aero had it a wee bit back.

[Larry Lyons]

Re: wing rib material

Thanks Forrest I will check with WAG AERO. Funny, I went to their web site today, looked around but couldn't find anything promising so did not call them. Yes, I asked Univair for a Cub rib repair section. Larry

[Forrest Barber]

Re: wing rib material

The ones out there are really not correct but will work dies are worn maybe, taked to Duke Iden today he gave me a line on the equipment needed to make the hat section , seems simple maybe someone has the stuff now?
The auto riveter is the same one ethat I saw at the factory a few years ago.

[Larry Lyons]

Re: wing rib material

I talked to Tom at Wag-Aero today. He wants me to send him a sample of a rib section from my plane. No problem! He says maybe it is something they would be interested in making, getting an approval for (with paper work of course) for all us poor saps out here. Univair has said they think the dies are out there, in the public domain; who has them? However I am still looking for a simple, cheap way to make a small repair to a few ribs with out a lot of paper work.
Larry

[jawinn]

Re: wing rib material

That stuff at Wag you're looking for is SKU M-315-000 and is $86. I had given thought to trying to make some as well, as I'd heard it was slightly different. Is there any reason one of the cheap bead rollers from HF set up with appropriate dies wouldn't work for rolling some out? It's one of those things I wanted to try when I had the time. Time being the operative word here.

[Forrest Barber]

Re: wing rib material

AH , time , the magic word. For simple repairs just follow AC 43.13-1B Chapter 4 figure 4-13 and pages around it. Are you the A&P , IA, if not they have to get in on the act. Did they not know about the approved repairs. Basically they show the reinforcement inside, I have used a flat piece into the bottom of the hat section and another wrap on the outside.
thank you for finding the Wag-Aero repair kit , that is the one they sent me. remember you can use a stamped rib in place of the fabricated one , especially on the butt ribs .... Hope you purist folks did not have heart failure.

[jawinn]

Re: wing rib material

One of my books tells me the later ribs are the replacement, but someone, don't remember who, told me the pre-war butt ribs have the advantage of not being nailed into the end grain of the spar, whereas the stamped ones do and tend to collect moisture there. I know I've asked this question too, and I admit I digress, but what exactly makes up the 5 piece butt rib? I've been trying to figure that out. I have a butt rib, stamped, that has the full section with no cut-out for the spar, as well as an inner piece that runs from the trailing edge to the aft face of the forward spar. Am I missing something? Is there a nose rib portion? Lastly, is rib stitching over the stamped rib acceptable?

[Larry Lyons]

Re: wing rib material

One of my books tells me the later ribs are the replacement, but someone, don't remember who, told me the pre-war butt ribs have the advantage of not being nailed into the end grain of the spar, whereas the stamped ones do and tend to collect moisture there. I know I've asked this question too, and I admit I digress, but what exactly makes up the 5 piece butt rib? I've been trying to figure that out. I have a butt rib, stamped, that has the full section with no cut-out for the spar, as well as an inner piece that runs from the trailing edge to the aft face of the forward spar. Am I missing something? Is there a nose rib portion? Lastly, is rib stitching over the stamped rib acceptable?

I have been thinking about the change to a stamped rib as the built up built up butt rib is a little flimsy. I will follow this post to see where it goes, of course I was following it anyway!
Larry

[VictorBravo]

Re: wing rib material

I have been thinking about the change to a stamped rib as the built up built up butt rib is a little flimsy.

There's a photo in Chet Peek's book of a built-up rib being tested with hundreds of pounds of sandbags on it. May be stronger than you realize. the trick of course would be repairing it and keeping all the strength.

As far as the T section, I would think you could fold up a piece of soft aluminum around a T-shaped extrusion, hammer or press it around the extrusion, then slide the extrusion out and heat-treat the hollow T-section.

[flybikefarm]

Re: wing rib material

I have a die that makes the repair section pieces, up to ten inches long. George

[Larry Lyons]

Re: wing rib material

George I may come over to see what you have and replicate it. As for flimsy I was referring to side load. Both butt ribs were pulled out of shape by fabric shrinkage. The right one being the worst as the fuel tank was in the way of some of the reinforcing.
Larry