The commercial pilot was on a Title 14, CFR Part 91, local flight. The pilot said he departed the airport to warm up the airplane's engine, and experienced carburetor ice. He said he elected to make a precautionary landing on a sandbar to check the airplane's engine. The pilot indicated the sandbar was rougher than he anticipated, and that he applied excessive brakes during the landing roll, and the airplane nosed over. In a written statement to the National Transportation Safety Board, the pilot wrote, "Better pilot evaluation of the landing zone, less braking, or more weight in the back of the aircraft could have prevented the accident." He said there were no known mechanical problems with the airplane prior to the accident. He said the airplane sustained substantial damage to both wings, the rudder, vertical stabilizer, and the right lift strut.