We have had two of these planes flutter their ailerons very badly at our club field. One plane crashed and the second one was nursed backed to the field an safely landed. On inspection of this second plane it was discovered that the gears in both aileron servos (JR4131) were stripped, several of the hinges were starting to detach from the wing, and the engine / firewall mount was damaged and loose.

The plane was repaired and new servo gears were installed. The plane was flown again and once again it fluttered and stripped out both aileron servo gears. No other damage has been observed. All linkages are very solid. Prior to this flutter problem the plane has had many successful flights with no hint of flutter. The plane is powered with a Moki 180.

Any comments on what may have caused the failure and has anyone else had flutter problems with this plane?