At 1147 Pacific time, the airplane impacted the ground in a storage facility after performing a precautionary low pass. The private pilot and private-certificated passenger sustained serious injuries. The airplane sustained substantial damage. Visual conditions prevailed. While maneuvering to land, the pilot reported problems with the airplanes landing gear. He performed a low approach, during which tower personnel reported the gear appeared to be down. Shortly after being approved to turn crosswind, the pilot reported another problem. A Boeing 747 crew awaiting takeoff subsequently reported the airplane then began a turn to the left while simultaneously descending. A few seconds later, the nose of the airplane appeared to pitch up, followed by a subsequent roll to the right and an inverted nose-down descent. They reported that throughout the sequence, the landing gear and flaps remained extended, and the airplane did not appear to be emitting smoke or vapors.
