Everyone has pretty muched described it on the money. If you ever hear a buzz or vibration sound at high speed, especially in a dive, IMMEDIATELY cut the throttle! I ave a GP U-Can-do 46 that will flutter the ailerons if you don't manage the throttle in dives. Luckily the worst thing that has happened was some cracked balsa in the aileron itself. I've added stiffer linkages and done a few other things and the problem is a lot better.