Folks who witnessed the attempted destruction of a stub spar at a past Gathering will probably agree that the spars have a significant margin of safety on the KRs. The spars were jacked up to the point of being bent probably 14" upward from the fuselage, and neither fuselage nor spars gave. Finally, the shear web started to split, but the spars were still fine and ready to accept more load. Anybody who witnesses that test had to walk away impressed with the spar strength, especially considering that in anything like normal (but bumpy) flight, the wings never even flex.
And despite all the concern about the WAFs and their connection, neither wing component is likely to fail, and in fact, never have in any kind of normal (not crash) flight. Larry Flesner and I have seen wings where the spar broke on impact with the ground at the bottom of a spin, and the spar broke a few inches from the WAF, not at the WAF or the connections from WAF to spars. Marty Roberts used to fly big guys at the Gathering hard and fast, with a gross weight of probably 1200+ pounds, and his g-meter would usually come back with 6g's or so stuck on it. He reset it for every flight. Just a data point, but I personally will lose no sleep over my spars breaking... Mark Langford, Harvest, AL ML "at" N56ML.com www.N56ML.com
