The Cessna 120-140 Association Forum

We are in the process of replacing the old fabric on the wings of our 1946 C120. These were last recovered in 1965!
Having inspected the structure after careful removal of the old fabric, it is evident that this will be at least the 3rd time of recovering. The Cessna wing clips are no longer an option for us to use as the attachment method for the new Poly Fibre process, as many of the holes in the cap strips are unfit for new clips. We intend to rib stitch the ribs that are non compression ribs, but this is not possible on the compression ribs. We note that the STC states the use of AD42ABSLF rivets.
Whilst using these rivets is acceptable to us, it will not be at all 'friendly' for the next time the fabric needs replacing. Drilling the rivets out is seriously time consuming. Consequently our preferred option is to use screws. Have any members ever used or knowledge of these (T4X4) screws as used on Aeronca wings? These are not covered by the STC. We seek best advice. Thank you

Update for info -
Having not had any posts in reply to our request for information, we have made the decision to fully rib stitch the wings. This will involve the addition of fitting wood inserts (a sort of cap strip equivalent, level with tops and bottom of the ribs) to spread the stitch width across the outer edges of the flanges that protrude on the compression strut ribs.
Any comments / further advice on this most welcome. Many thanks.

Taildraggers has an stc to use "pop" rivets everywhere. I'm convinced that drilling them out is less work than rib stitching would be. Or, if you insist, you could pop rivet the troublesome ones and rib stitch the rest. (I'm unclear on what the basis of approval for the rib stitching is...) Ercoupes also use PK screws, so I would think you could get approval for them as a deviation.

That said, you probably don't want to take my advice as I'm a Campbell...

FWIW, this (below) is the only 140 I've personally seen with rib-stitched fabric/wings. As I recall, Marty Lochman accomplished via a "field approval" as part of major total (multi-award-winning) restoration. He isn't active on this forum for quite a while, but prob accessible via net. Mac

Iain

As you already know, my aircraft is rib stitched. Coincidentally Graham R’s a/c that you may have noticed had a wing removed a couple of weeks ago, had fabric attached with screws. Maybe contact Graham by WhatsApp to get the details?