Ed, Although my Alon isn't 40-50 years old yet your observations about high speed cruise and flutter are right on target. I too noticed that the controls on my coupe were sloppy and at the last annual replaced eleven Heim bearings, clevice pins and all the attachment hardware. What a difference it makes--- much more positive control of all three control modes and definitely better flying attitude in virtually every maneuver. I would urge ever couper to make sure their controls don't have the kind of excessive slop that had developed in my Alon over the years. My flying buddy and I have checked quite a few coupes and observed the same sort of condition or worse. David Cross Alon N5600F --- Ed Burkhead <[EMAIL PROTECTED]> wrote: > 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 >
_________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com
<<attachment: winmail.dat>>
