My most interesting flight so far

[Hagar]

no please continue, I'm a sponge for airplane info

There's not much I can add. Sean will no doubt inform us when he finds out anything of importance. Meanwhile, if there's anything you think I can help with (which I very much doubt) then I suggest we continue this via PM.

I finally found what I was looking for. The official regulations for fabric covering. http://www2.tech.purdue.edu/at/courses/at308/Technical_Links/Ac43-13-1B/CH2_1.pdf
It has several pages devoted to lacing (what we used to call stringing) & approved seams & knots. That should keep you quiet for a while.

[The Ruptured Duck]

Yeah, I gotta like, do my homework now

[Aerophile]

Holy cow Sean.  I've had engine failures, bird strikes, etc., but never had a piece of the airplane fall off... yet.  Hats off to you and CFI Bob.

[beaky]

I've gotten some feedback from some type owners on the 120/140 Association website who are mentioning "repair" and "glue".
That's not conclusive, but...
I wish I'd had the presence of mind to look at the seams on the right wing as a comparison... but no matter; someone will get to the bottom of this I'm sure. Bob doesn't seem the type to shrug it off- he flies this plane regu;arly, and will probably want an explanation.

I agree with Hagar that it's odd that this panel wasn't, apparently, wrapped over the leading edge towards the bottom... I'm not an expert, but in the one class I took in fabric wing-building (where we made a mock section of wing, with a wood frame, aluminum cap and trailing edge, and the stitching method), that is how we were shown to do it.
It makes sense, because regardless of how it happens (the ancient debate), the fact remains that there is always an area of low pressure above a wing in flight and an area of high pressure below, so the skin would be getting "pulled at" more on that critical upper surface... wrapping the upper skin over the leading edge would seem common sense in that case.

Hagar- you say the clips don't hold the panels in place? What do they do, then? Don't they pass through the fabric?

[EDIT] I missed your eearlier comment about the clips... yes, I can see now how it works: the edges of the panel (patch?) are glued on, and the clips pass through the fabric at intervals along the ribs to prevent ballooning.

It sure does seem more and more like a patch now, and not a very good one. I've heard of clips, rivets, stitching, or whatever does that "anti-ballooning" job on any fabric wing coming loose, but usually it's not a big factor initially, more something to be fixed before the next flight... provided the glued seams stay put!!

I hope whoever did this work gains some enlightenment from this... it's a very bad area to be "cutting corners" with improper work or materials, not that any area is "good".

[61_OTU]

A real horror story Sean, glad to have you back in one piece  ;)

Steve