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Dana
10-12-2014, 07:20 PM
I have a Fisher 404 that hasn't flown in about 10 years. The issue is the rib stitching, or lack thereof. As near as I can tell, this design (95 mph Vne) allowed glue to secure the fabric to the ribs in lieu of rib stitching. On my plane, I don't know whether glue was used (some of the fabric is stuck to the ribs but some is not), but the builder rib stitched it not with the usual waxed chord, but with what looks like ordinary sewing thread, most of which is broken. Anyway, the A&P who's doing the condition inspection and I are discussing the best way to deal with this, the safe answer being to strip the fabric (which is in good shape) and , My thought is to restitch the existing fabric, with new finishing tape over it, but the A&P's concern is that it isn't a documented "standard" repair technique so he's reluctant to sign it off. Thoughts?

Jim Hann
10-12-2014, 09:12 PM
Dana, I had this exact issue with my certificated PA-22/20. Ceconite has no leeway on the stitching, I would have had to restitch exactly in the same holes which meant soaking off the tapes and doing all that labor. I elected to recover the wings and tail.

Since yours is an EAB, you can stitch it however you want, as long as an A&P will sign off the Condition Inspection. Recovering is probably the easiest way to do it, although not the cheapest. If the fabric was applied in full accordance with an installation manual I would say consult that company. It sounds like it wasn't done that way, so I don't know who you would turn to. Of course some folks will say it is an EAB, you can fix it any way you want! The amount of labor involved with removing all the finish tapes and broken stitching cord isn't a big deal if you want to do it yourself.

Good luck with your decision.

Jim

1600vw
10-13-2014, 05:58 AM
When doing the repair on my airplane. We did not have to soak the tape to get it off. After I cut it with a knife I was able to pick it up and just pull it off. This to was ceconite fabric. If I remember correctly the old system used was poly. We used the Stewards System for the repair. After a few years it looks good.


I was not showing this repair in these pics but you can see it on the wing. I have not finished matching the blue paint. The airplane is getting new fabric in the next year or so.

42314232

rwanttaja
10-13-2014, 09:32 AM
I have a Fisher 404 that hasn't flown in about 10 years. The issue is the rib stitching, or lack thereof. As near as I can tell, this design (95 mph Vne) allowed glue to secure the fabric to the ribs in lieu of rib stitching. On my plane, I don't know whether glue was used (some of the fabric is stuck to the ribs but some is not), but the builder rib stitched it not with the usual waxed chord, but with what looks like ordinary sewing thread, most of which is broken. Anyway, the A&P who's doing the condition inspection and I are discussing the best way to deal with this, the safe answer being to strip the fabric (which is in good shape) and , My thought is to restitch the existing fabric, with new finishing tape over it, but the A&P's concern is that it isn't a documented "standard" repair technique so he's reluctant to sign it off. Thoughts?
I believe that Fisher specifies only gluing the fabric to the ribs, that the instructions don't include rib stitching. Nothing wrong with rib stitching, of course. The argument could be made that the existing rib stitching is superfluous.

I used to have people complain when I left one of the 13 screws off a particular inspection panel on my Fly Baby. I would point out that the designer specified only four. Eventually I installed a panel with only four screw holes....

Ron Wanttaja

1600vw
10-13-2014, 01:35 PM
My Blue prints show rib stitching. But this is the V Model. My first Avenger did not have rib stitching. It was not the V model. I did not have blue prints for that airplane.

Tony

Dana
10-13-2014, 07:17 PM
Fisher only specified gluing, but the original builder stitched it (it's unclear whether he used glue as well; some of the fabric appears to be adhered to the ribs but in other places it clearly isn't). Perhaps he thought the stitching was superfluous and that's why he used such light thread, but at any rate, the stitching has failed and so has the glue (if it ever was present).

My position is that restitching through the original finishing tape, with additional tape over would be stronger than the original that lasted over 350 hours, but as Jim points out the A&P will have to be comfortable enough with such a repair to sign off the condition inspection... which he's reluctant to do.

martymayes
10-13-2014, 08:12 PM
Dana, imagine you had given the aircraft a "pre" condition inspection and noticed the broken rib stitching. So you pull out a roll of stitching cord and go to work. Then install a finishing tape over the new stitching and touch up the paint. Would the A&P have had any issues? Of course not. Now he's convinced himself nothing short of a complete recover will be adequate.

I know what I would do. With your past ultralight experience, I have complete confidence in your abilities.

martymayes
10-13-2014, 08:16 PM
I believe that Fisher specifies only gluing the fabric to the ribs, that the instructions don't include rib stitching. Nothing wrong with rib stitching, of course. The argument could be made that the existing rib stitching is superfluous.

Is there any fabric covering system where the manufacturer will say no rib stitching is required in this application, our glue is more than adequate to hold the fabric to the ribs?

Dana
10-14-2014, 04:22 AM
The Ceconite manual says rib stitching (or equivalent) is required, but it was written before such slow light aircraft, borderline ultralights, were common. Oratex (http://www.betteraircraftfabric.com/common-questions.html) (the new iron on fabric) says "That just depends on the requirements as set forth by the designer of your aircraft. If the plans call for rib stitching, then you must rib stitch. If the plans call for rivets, you will use rivets."

Any repair is complicated by the fact that the builder painted the plane with automotive enamel over the dope. Beautiful, but trickier to repair. I don't want to have to remove the existing finishing tape since removing the enamel, the the dope down to the clear coat, would probably be more work than a full recover. However, I can't see any reason why it would be a bad idea to stitch through the existing finishing tape, and apply new tape over that. Oratex tells me their finishing tapes can be applied over any existing finish provided that original finish is still secure to the fabric.

1600vw
10-14-2014, 06:00 AM
My Fisher plans do not say to use rib stitching. But the blue prints show the ribs stitching in place. Auto paint was used on my airplane and the repair was easy. I too was worried about this auto paint and how hard it would be to repair. It was a non issue.

Again I used the Steward System and it was an easy repair and has held up great in the 3 years its been on. This winter it will be going into the 4th year.

Tony

Dana
10-14-2014, 09:10 AM
Tony, what were you repairing? You had poly-fiber first, then repaired over it with Stewart? How did you attach the new finishing tape?

1600vw
10-14-2014, 01:48 PM
Someone climbed into my airplane when I had the canopy off. They then got out on the wrong side and broke a rib. We had to cut the fabric on the rib, then scarf joint the rib. My A&P made one of the best scarf joints I have ever seen. This man had never worked with wood and he did a great job. I was amazed how big the scarf joint had to be. He explained it had to be so many inches long or something like this. The break was only a cracked rib but by the time we where done we had cut the fabric 3/4 the wing cord length.

After the repair to the rib, we had to stitch the fabric back together. We had to put cap strips back on the ribs, then glue the fabric to this. We then put a strip I will call a cap strip over the stitched fabric. Then rib stitched through this. Then a cap strip went over the ribs stitching.

We used the Stewards system and it worked great. This was so easy to use and I would do it again in a min. I should have made a video showing this repair.

I also had a hole in my fabric. Before I purchased my airplane someone crawled under it when it was in the trailer they kept her in. This person had a screw driver in their back pocket and put a big hole in the fabric on the underside of the tail feathers. The hole was about 5x5 in size. I scuffed up the paint with some MEK and sand paper then used the Stewards System to repair this hole. Again it worked great.

Dana if we lived closer I would come and help you. Just jump in and start this. You will find its real easy to repair. You will be saying, I want to recover these wings by the time you are done. Its that easy. The Stewards System makes it such a non event you will be wanting to recover the complete airplane.

For paint I will be using auto paint. My repair is going on 4 years, no cracks runs or errors. lol Auto paint has come a long way from days of past. Nothing was added to this paint to make it flexible and it has not cracked at all. I even push on the fabric trying to crack it and have not been able to do so.

Keep us posted as to your repair and post some pics. I love pics.

We used two needles when repairing this. One was bent or curved and the other was straight. I went to a local upholstery fabric repair shop and picked up my rib stitching thread. My A&P IA told me to go get it there. They ask how much do you need, then pulled off what I need from a huge spool and handed it to me. They did not charge me anything for it. I believe they gave me 30 feet of it.