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I'm a private pilot, and I have some questions to those who have knowledge of the aeroelastic effects and flutter phenomenon. I would like to talk a little about aerodynamic flutter onset speed and flight control malfunction. It is known that freeplay, worn-out control rods or slop in flight control cables might induce flutter.

What I'm interested in is how critical flutter speed is affected by those problems. I'm wondering especially about a cable control failure where the surface would be disconnected and freefloating. There are small light sport aircrafts and even some FAR 23 standard certified aircrafts which don't have mass-balanced surfaces, especially ailerons which I guess would be more prone to flutter. How critical flutter speed lowers in a situation like that (and how prone to violently flutter are these ailerons in an emergency disconnected sitation)? Is there a linear drop in flutter speed? Can it reach even lower speeds in the normal operating envelope e.g. below usual cruise speed? Normally, assuming no malfunction, flutter speed is at least 10% above Vne (never exceed speed) or Vdf (max dive test speed used during certification flight test). How do you think these things might change?

The same about the others control surfaces e.g. a broken trim tab linkage.

I really appreciate your help. Thank you very much!

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It's a very good question. Clearly that's why they are mass-balanced. –  Mike Dunlavey Jan 2 '13 at 15:57
Check this link. Flutter is a dynamic feedback condition that depends on a number of things. –  Mike Dunlavey Jan 2 '13 at 17:02
Already read it. I think I read tens of papers on the Internet regarding flutter. However, I can't figure out on my own, I hope someone here has some practical experience regarding it. Also, those unbalanced surfaces seem more at risk in a cable failure scenario, that's why I'm wondering. –  Steve Jeff Jan 2 '13 at 17:12

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