Larry Flesner wrote: > can someone convert that to non-engineer speak? If that was a factor > it's amazing it went 800+ hours before failure.
I think what they are saying that at the original inspection, the balance weights are inspected and the aileron balance is verified, but subsequent inspections ("annuals" I presume) don't go into that kind of detail to verify that they are still capable of counterbalancing the ailerons.
As we all know, repainting, re-glassing....any number of things can change the balance over the years, especially something like shaving a bit of a balance weight to make it more aerodynamic for example, can alter the balance enough to allow flutter to be induced.
Jim Faughn lost a balance weight at one of the KR Gatherings, and was lucky enough that Marty Roberts was behind him and saw it fall off, which is pretty crazy good luck! Several folks came together to fashion a new one, and he flew the plane home afterward, properly balanced. I've been flying that plane for the last 15 years or so and have put a lot of hours on it. Two years ago Troy Petteway noticed that the same aileron balance was loose in the annual condition inspection two years ago. I disassembled it, and found that the countersunk screws had sunk further into that thin quarter inch of spruce (that acts as the aileron spar) to the point that they were about to pull all the way through! Bottom line is that countersunk screws are not a good idea there, nor are aluminum brackets (which caused the first failure). I repaired the countersunk hole area and reinforced the spar, and used "pan head" screws to retain the weight to the spar. No problems since, but it's something I now check on more regularly.....
Mark Langford m...@n56ml.com http://www.n56ml.com Huntsville, AL -- KRnet mailing list KRnet@list.krnet.org https://list.krnet.org/mailman/listinfo/krnet
