Wing tube failure at center due to holes drilled in tube
Here's a failure that I have not run in to yet (until yesterday). Entered a snap from medium speed and both wings separated from the plane (35% CAP). The aluminum tube broke in two at the exact center. I had three holes drilled (for number 6 screw) to lock the tube inside of the phenolic housing. The reason there was three holes is that I have rotated the tube over the years in order to make new holes at the ends of the tubes (where the wings are screwed to the tube). This plane has done hundreds (maybe thousands) of snap rolls and other agressive manuevers (walls, blenders, etc.), and the tube finally snapped. The fuselage was destroyed in the resulting "lawn dart", but the wings fluttered down unscathed. In the future I will never drill a tube anywhere the middle, but rather, use a clamp to lock the tube to the fuse.