P.S. to my earlier post on the 120 hp STC: Fred Weick continually urged us to keep in mind the transient, high wing loads in turbulence on a normal day. They are 40 (now 50) year old wings, he kept emphasizing.
I will only do high speed cruise in nice smooth air above the bump level, personally. Even the 108 mph maneuvering limit should be hedged on bumpy days. Remember that the maneuvering limit is the point where the wing is supposed to stall before the design load limit is exceeded. Here's another reason to be cautious about maximum speeds: In _perfectly_ smooth air about 18 years ago, I did a smooth approach to 144 mph in a gentle dive. I got aileron flutter at somewhere between 136-140. It felt like hitting a washboard gravel road in your car. I don't know how I made the analysis so fast but in something less than two seconds, I figured out what it was and decided I needed to pressure load the aileron to stop the vibration. I saw the fluttering aileron stop fluttering the instant I loaded it by turning the control wheel. Consensus is that I was _extremely_ lucky and that there is so little time involved from the onset of flutter before airframe failure that it's luck I had the time I did to solve the problem and act. (Luck fights on the side of the prepared. Suggestion: when flying, practice imagining washboard vibration and immediately loading the control surface by turning the wheel and pulling back on the elevator. I had thought about that that when I read the flutter descriptions during my initial training. Pre-decisions, especially practiced ones, can save your bacon! Analysis was, that there was more than specified slop in the controls. (A series of non-Coupe mechanics who probably checked them and thought they felt just fine.) Even then, we just put washers and such in the linkages and I flew cautiously for years (dumb) until we went completely through it last year replacing parts. -- Ed Burkhead East Peoria, Ill. N3802H, 415-D
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