I've experienced flutter a few times. I have a SPAD Debonair that in a full powered dive will exhibit wild gyrations of the tail surfaces. Due to the flexibility and strength of the construction materials, simply reducing the throttle and adding up elevator immediately eliminates the gyrations. Inspections of the plane after each instance have revealed no harmful effects.

In the other case, a plane I designed myself (see my hanger for pictures) designated as the S-3, was a great flyer. One day (July 4), the throttle linkage came off, leaving the plane at about 3/4 throttle. I continued to fly it for about another 10 minutes trying to run out of fuel. At that point, I took the plane up to about 400 feet and put it into a 45 degree down line trying to get the klunk out of the fuel. The plane gained speed as expected, and at about 200 feet we hear a very loud POP. The horizontal stabilizer had sheared off both sides. It stayed attached to the elevators and actually remained connected to the plane. When the elevator carried away, it also snapped the rudder linkage and tore the rudder off its hinges.

The plane continued to fly for another 10 minutes (it reliably pullied toward the nose into a loop, which I could use in connection with the ailerons to keep the plane in the air and over the field. Finally it go to close to the ground before running out of fuel, and the resultant debris field.

Before and after pictures.

Brad