To rib stitch, or not?

Nathan K. Hammond · Post by **Nathan K. Hammond** » Sun Feb 24, 2008 14:25

Was there anything protecting the edge of the rib? Masking Tape maybe?

nkh

Post by **joea** » Sun Mar 09, 2008 12:06

Well ladies and gents, was just at the Cactus fly-in and found something very interesting.

There was what appeared to be a nice Champ for sale, at about $24k or so. A nice looking flier, or so it seemed.

Was approached later on by a gent looking for a Champ. I mentioned this one and he said that this was why he was looking for me! Seems that he noticed more than I did (the airplane was not going to be judged so I did not look at it closely) and he found that it had been rib stitched instead of using the approved PK screws. This gent asked about it and was assured that it was legal and that they had a 337 for the rib stitching.

I had to tell him that the ACA factory and everyone else that I had heard from on this subject said that it was not legal, nor not really safe.

Joe

Nathan K. Hammond · Post by **Nathan K. Hammond** » Sun Mar 09, 2008 13:28

But if he got a 337, then it's legal... for that airplane...

nkh

Post by **joea** » Sun Mar 09, 2008 13:40

He does have a 337, but like the post on the first page by Richard, is it safe?

In my eyes it is not and I would not buy an airplane that had been rib stitched unless the price was good enough to allow me to recover the wings in a safe manner.

Just me... I like safe more than just legal.

Joe

Richard · Post by **Richard** » Sun Mar 09, 2008 14:19

The 7GCBC that I referred to earlier, had several damaged ribs from the rib stiching failing in flight.
I would want to see the actual 337 for covering the particular aircraft and read for myself, that a FAA inspector had approved rib stiching; or was it just the usual 337 for recovering the a/c
Then I would want to use that guy for 337 approvals on my planes, which the Spokane GADO refuses to even consider.

Richard

jerrymjr · Post by **jerrymjr** » Mon Mar 10, 2008 16:14

I would trust rib stitching on a 7AC before I would on a 7KCAB...if you get my drift. (Assuming there were 337's on both)

MikeB · Post by **MikeB** » Mon Mar 10, 2008 17:56

Guess I don't see any real benefit to rib stitching unless someone wants to do it like Wilbur and Orville. Pop rivets I could see assuming there was enough rib flange material which appears to be marginal. Guess I'll use the tried and proven PK screws with the little humps

for whatever it's worth.

Mike Berg

marklamon · Post by **marklamon** » Mon Mar 10, 2008 21:56

We have a Champ at our field that was covered almost 40 years ago with ceconite. It was ribstiched and there is no masking tape on the edge of the ribs. None of the stitching has let go that I can see.
If I'm thinking right the reinforcing tape that goes down just before you ribstitch will offer protection to the stiching if the tape is as wide or better yet slightly wider than the rib.

Ya never know, it could have been the weekend and the guy forgot to order PK screws. Then the local airport knowit all says "What we allways used to do was use rib stitich the dang things". A tube and fab shop always has cord laying around and the rest is history. Or maybe the boss was a tightwad and did not want to buy anything else for the project

Mark

Nathan K. Hammond · Post by **Nathan K. Hammond** » Mon Mar 10, 2008 22:07

That's what I'm saying. I've got a T-cart in the shot right now with 25 years on the covering; metal ribs and stiched with no cut cords.

Mike, there are a couple benefits to stiching. When you stich, the load is supported by the entire rib because the cord goes around the top and bottom. Screw, rivets and clips try to pull the ribs apart, were stiching trys to compress the ribs. Think of it like lifting a 5-gallon bucket of water from the bottom as apposed to lifting it by the handle. Second; screws, rivets and clips beat up the ribs. Holes get elongated and enlarged, and in some cases you have to drill new holes that remove material and weaken the rib further.

nkh

Nathan K. Hammond · Post by **Nathan K. Hammond** » Mon Mar 10, 2008 22:10

And make no mistake, I'm not trying to pick a fight. I just want to warm everybody up, so if I show up with stiched wings, you wont point and laugh.

marklamon · Post by **marklamon** » Mon Mar 10, 2008 22:26

Nate you will not be the only one there with stitching. That orange and white Champ that the guy started flying when he was 8 is rib stitched

I think you should go with 2 inch spacing outside the prop and 1 inch spacing inside the prop. Also 1 inch spacing on the tail surfaces.

mike newall · Post by **mike newall** » Mon Mar 17, 2008 17:58

My last Champ was rib stitched - very nice job as well. If I get round to do another, I will stitch and use normal methods to ensure it works OK.

We are fortunate though that here in Old Blighty we run our Champs on your version of an Experimental so we don't need 337's etc. We get the work inspected for suitability and quality and we move forward.

If you want interesting........ we are just completing a re-cover of the tail surfaces of my friend's Tiger Moth. Last covered 40 years ago in linen, pulled the fabric on the annual, fabric A-OK, structure was sound but Wow is it lightweight compared even to a Champ. We were shocked at the size of the ribs and webs etc.

Covered it in dacron, just about to tape it up and dope it.

Bill Bussel · Post by **Bill Bussel** » Tue Mar 18, 2008 09:05

A question. What does AC use to fasten the cloth on the wings? Am asking because I and several others who have discussed this issue am not near any AC planes and none of us can remember seeing how it is done.

Nathan K. Hammond · Post by **Nathan K. Hammond** » Tue Mar 18, 2008 12:21

American Champion uses Fabric Pop Rivets.

nkh

Post by **joea** » Tue Mar 18, 2008 14:52

Nathan K. Hammond wrote:American Champion uses Fabric Pop Rivets.

nkh

But just to clarify, this is with the newer version of the thicker ribs.

National Aeronca Association Bulletin Board

To rib stitch, or not?

To Rib Stitch, or Not