National Aeronca Association Bulletin Board

I’m in the middle of the annual on my 1946 7AC. My AI was tapping his hand on the bottom of the wings and came across a loose block of wood between the third and fourth ribs (from the fuselage) aft of the rear spar on the right wing. Through a scope the block appears to be about three or four inches long, three-quarters of an inch square, and smooth with no splinters or signs of glue or varnish. It doesn’t appear to be triangle-shaped like a gusset but we can’t tell.

There’s an inspection hole one rib over and ahead of the rear spar that we’re working from. But since the block is aft of the spar and too big to pull between the spar and the fabric, there’s no getting it out without cutting a slice in the fabric (or adding an inspection hole, which at quitting time yesterday we considered as an option). As much as I hate to make a cut, the block has to come out.

So what is it and where did it come from? I looked on the drawings for such a piece and found nothing. My dad recovered the airplane in the late 1970s and he has no ideas. I’ll take any response – informative is preferable but entertaining is acceptable.

Used as a spacer to inspect the spar AD?

I would use a set of mechanical fingers and pull the block under the rear spar and out the inspection hole. A stick with back wound tape might be sticky enough to pull it up too the spar, but i doubt it'll have enough stickum to pull itmunder the spar. Don't worry if the block is bigger than the gap, the fabric should have enough give to allow the block to squeeze through.

What ever the case, you need to get it out because the aileron cables run back there and are not protected.

nkh

It might be a block used under the leading edge material. Sometimes the nails will break and let the block loose.
If you can touch it with a wire or cable, get a sticky mouse trap and put the sticky stuff on a retrieval device. It works for pulling wayward bolts from inside of a V2500 on an Airbus, dodged a bullet on that one.
Paul

Thanks Paul and Nathan. We’d tried the mechanical fingers but couldn’t get a grip. And I like the sticky mousetrap idea but it’d probably be easier to train a mouse to crawl into the wing and retrieve the block than it would be to manipulate a sticky stick between the spar and the fabric from one rib over. I really do appreciate the ideas though.

At first we lifted the tail and bounced the block to the back of the spar. But even though it as closer, we couldn’t grab it. And we also tried what I dubbed the “Tickle Bee” approach in honor of the 1960s kids’ game that used a magnet to pull a plastic/metal bee through a maze -- I thought if the block had a nail or some metal on it, I could use a strong magnet to pull it forward, down, then out. That didn’t work because apparently there’s nothing ferrous in the block.

Basically it’s inaccessible. So yesterday the AI glued an inspection ring in a spot where he can cut a hole and reach in there and grab it.

I’ll post a picture of the block when I get it.

Ron Schroeder
Minneapolis Stanton
Champ N2488E

The culprit.

For those of us who are as dumb as we are good-looking......


WHAT IS IT? WHERE DID IT COME FROM????

Sean