Carl asked:
> I was wondering whether you'd share the identification and > correction for flutter and what would cause it to begin with. Carl, On a beautiful sunny day, I was returning to Iowa from the Great Little Chicken Ranch Fly-in Picnic at Leonard Page's chicken farm in northwest Arkansas. I was up high, 9,500' or 11,500' or so over Missouri and saw the scattered cumulo-puffies below me starting to build into an undercast. Not wanting to get trapped on top, I started a cruise descent. As the air up high was perfectly smooth, I decided it'd be a nice day to do a gentle dive and touch the Vne at 144 mph. At about 135 or 140 or so, my plane suddenly felt like it was a car on a washboard section of gravel road. There was a vibration just like that. Somehow, I could tell that it was coming from the left and my head snapped over to the left. I saw the left aileron fluttering. Perhaps it was because I was primed to think about flutter, knowing that I was at high speed. Somehow, I instantly understood that it was flutter and figured out I needed to push on the aileron to make it stop fluttering. Luckily the mental connection was instant and I moved the yoke smoothly and quickly to the right to load the control push rods and put pressure on the aileron. All this was in just 2-3 seconds. Maybe less. The flutter stopped instantly. Gently leveling out, I checked the controls and all seemed normal. At **normal** speeds, I continued on home and thoroughly checked the plane out before the next flight. There was no damage to the aileron or any linkage that I could find. What we did find was that there was excess play in the aileron control system. It did not pass the test specified (clamp one aileron and measure play in the other one). Experts, please post which book has that info. Because I was a no-income college student at that time, I shimmed all the pushrod linkage connections with washers and got it to spec. (Not recommended.) Then, I flew below 110 mph. As soon as I could, we replaced all the pushrod ends which cost less than I'd expected. I've been assured by lots of people that I'm very lucky. I believe it and agree. _________________________ We had lots of messages about the Sebring accident when it occurred due to the report by the ATP on the ground who said he saw the aileron flutter. We have not seen the final report on this accident. _________________________ The other flutter accident I've heard of is one for which I haven't seen the final NTSB report. It was over Ohio, I think, back when I was editing Coupe Capers in the early '90s and I was able to talk to the investigator. At that time, he thought it was elevator flutter that had broken the tail cone. When the tail cone broke, the nose pitched down abruptly, the seat belt or its attachments broke due to the very high negative g load and the pilot was ejected (much like the two people at Sebring). That investigator thought the aerodynamic trim tab might have come disconnected or loose and the spring had not been able to hold the tab against the stop. So, when the trim tab moved freely, the elevator started to flutter. (I also now make sure my trim tab spring has strength and the trim tab cable is firmly attached at each annual.) Please, y'all, make sure your control system is up to specs. Ed
