Citationjet (C525/C526) - CJ I / II / III / IV
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Engineer
Flight Crew Last 90 Days 40; Flight Crew Total 6800; Flight Crew Type 270
Situational Awareness
Aircraft Equipment Problem Critical
Flight Crew Overcame Equipment Problem; Flight Crew Took Evasive Action
Aircraft
Level flight; autopilot engaged; smooth air; airspeed 265 knots. A rapid onset of aileron divergent flutter on the left aileron shaking the yoke and whole aircraft with no movement of the right aileron. Reduced power rapidly to 230 knots flutter went away and advised ATC of the change of flight speed. Instructed First Officer to look for nearby landing airports in the event the flutter was going to return. ATC gave us [RNAV] arrival but ZZZ Center gave us direct ZZZZZ with no speed restrictions to follow. Descent at 230 knots; flutter did not reappear and flight into ZZZ was normal and uneventful.
Reporter indicated the aircraft is equipped with a Tamarack Atlas Active Winglet installed per Supplemental Type Certificate. Reporter is concerned that this modification may have also been an issue with a recent Citation hull loss.  On the reporter's aircraft; maintenance found the aileron trim actuator was out of tolerance.  Once the actuator was replaced; the problem has not returned.
CE-525 Captain reported aileron flutter on aircraft with Atlas winglet modification; likely due to a faulty aileron trim actuator.