On Sunday, November 5, 2017 at 10:28:45 PM UTC-5, wrote:
A few 20's were produced with slightly different incidence angles in the wings..........yep, the wings were not hooked on straight! I'm sure those ships liked to spin when flown too slow. Schleicher had several "eccentric" rear lift fittings to solve the problem. I'd bet they are all fixed by now, but if your 20 always seems to turn one way, your wings may not be true!
JJ

Errata:

Interesting. I recall that a few ASW 19s had the same problem...and solution: i.e., eccentric rear lift pins from the factory. My memory might be playing tricks but the guy who told me about it had a '19, not a '20. I've always wondered how the wing was twisted after that since the spars and main pins weren't altered.

My memory might be playing tricks, Part II, but regarding flap flutter, I also recall hearing that some early '20s had a slight amount of "slop" in the flap drive that was fixed by smearing epoxy on the end of a long wooden stick or dowel, jamming it into the wing root at the appropriate point, waiting for it to harden up, then breaking off the stick/dowel. Apparently a bunch of owners had theirs done on a rain day at a big contest (late 70s/early 80s?). That seemed to address the flap flutter.

I believe Rudy Mozer's ASW 20B was one of four brought over for the Worlds (Hobbs, 1983). When I saw it that spring, it had lower flap seals that were beryllium copper (to accommodate the landing flap deflection?). Pretty nifty looking. Beryllium copper dust is toxic so that might have killed any enthusiasm for using this material.

Chip Bearden