If it's an ARF check the tail construction. Flew my Model Tech SU-29 ARF Sunday (probably had 50 flights on it) and put it into a 90 degree left bank to enter a knife edge pass. Heard about two seconds of flutter (never fluttered before) and before I could cut the throttle the tail blew off. Pretty impressive actually, the vertical and horizontal surfaces came off in about five pieces and fluttered to the ground while the rest of the plane went into a nice spin that I could actually slow down with the ailerons. It hit the ground fairly slow so the damage was minimal (didn't even break the prop). When I looked at the mounting surface for the tail surfaces on the fuse the glue had only been applied to two small areas front and rear (about 10% of the mounting area). Didn't like the tail anyway.

Mike