There was a MASSIVE thread a year or so ago on RCUniverse. Yours truly lost BOTH ailerons and managed to land it inverted in tall grass with rudder and elevator. I switched to dual ailerons and beefed up the servo bays. See if you can find the thread. It has tons of info about that problem. Some Extras fluttered badly, and others had no problem. I had strong servos and carbon fiber rods with rocket city ball links when it came apart, and it wasn't going over about 60 mph.

JW