Narrative:

At the time of the incident we were in cruise flight (IAS of 155 mph) the ailerons started a flutter that was transmitted to the control yoke which briefly made the ailerons unusable. The up and down movement of the ailerons were approximately 6 inches. At once we started a speed reduction, the flutter stopped at approximately (125 IAS mph). During post flight inspection the aileron trim tab on the left aileron had broken from its connecting rod. The aileron showed signs of buckling on the bottom side. A report was made that evening to the FAA. They advised to call the local FSDO the next morning. Callback conversation with reporter revealed the following information. Reporter states he has never been so scared in an airplane. Mechanics found that the trim tab broke at the attachment point then the flutter occurred. Reporter had thought reverse happened. Not able to find the bolt, but mechanic believes it broke where it attaches to the actuator. All appeared normal in the preflight. Reporter talked to NTSB as required and was referred to local FSDO. They did not want to do any follow up. Has asked around if anyone else experienced such a problem. He is the original apparently.

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Original NASA ASRS Text

Title: SMT EXPERIENCES SEVERE AILERON FLUTTER AFFECTING CTL YOKE SO AILERONS UNUSABLE. BY REDUCING SPD PLT STOPS FLUTTER.

Narrative: AT THE TIME OF THE INCIDENT WE WERE IN CRUISE FLT (IAS OF 155 MPH) THE AILERONS STARTED A FLUTTER THAT WAS XMITTED TO THE CTL YOKE WHICH BRIEFLY MADE THE AILERONS UNUSABLE. THE UP AND DOWN MOVEMENT OF THE AILERONS WERE APPROX 6 INCHES. AT ONCE WE STARTED A SPD REDUCTION, THE FLUTTER STOPPED AT APPROX (125 IAS MPH). DURING POST FLT INSPECTION THE AILERON TRIM TAB ON THE L AILERON HAD BROKEN FROM ITS CONNECTING ROD. THE AILERON SHOWED SIGNS OF BUCKLING ON THE BOTTOM SIDE. A RPT WAS MADE THAT EVENING TO THE FAA. THEY ADVISED TO CALL THE LCL FSDO THE NEXT MORNING. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO. RPTR STATES HE HAS NEVER BEEN SO SCARED IN AN AIRPLANE. MECHS FOUND THAT THE TRIM TAB BROKE AT THE ATTACHMENT POINT THEN THE FLUTTER OCCURRED. RPTR HAD THOUGHT REVERSE HAPPENED. NOT ABLE TO FIND THE BOLT, BUT MECH BELIEVES IT BROKE WHERE IT ATTACHES TO THE ACTUATOR. ALL APPEARED NORMAL IN THE PREFLT. RPTR TALKED TO NTSB AS REQUIRED AND WAS REFERRED TO LCL FSDO. THEY DID NOT WANT TO DO ANY FOLLOW UP. HAS ASKED AROUND IF ANYONE ELSE EXPERIENCED SUCH A PROBLEM. HE IS THE ORIGINAL APPARENTLY.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.