According to the flight instructor and the pilot-rated student, both believed the airplane had been fueled at the time it was pulled out of the hanger by line personnel, and they had observed a fuel truck parked near the airplane prior to the flight. The student had performed the preflight inspection, during which he interpreted the fuel sight gauges as indicating full fuel; however, he did not visually check the fuel in the tanks. When the instructor arrived at the airplane, he asked the student how much fuel was on board and the student said the tanks were full. The flight departed from Lynchburg, Virginia and made several takeoffs and landings at a nearby airport. About 1 hour into the flight as the airplane was 1,000 feet above ground level, the engine lost all power. As the instructor began a turn toward a nearby pasture, the engine started producing power again and the instructor chose to continue the turn, heading toward the nearest airport. The engine then lost all power again. No longer able to glide to the nearby pasture, the instructor flew the airplane straight ahead and let it settle into the trees. The airplane struck the trees and terrain and came to rest inverted. Examination of the wreckage by a Federal Aviation Administration inspector revealed substantial damage to the wings and fuselage. The inspector recovered about 1 pint of fuel from each fuel tank. Additionally, neither pilot reported any mechanical malfunctions or anomalies that would have precluded normal operation of the airframe or engine. After the accident, the flight school held safety briefings with its instructors, faculty, and students. These briefings included discussion of the circumstances of the accident, and the implementation of policy changes related to pre and post flight responsibilities of students and instructors, new fuel level measuring procedures, and dispatch records of fuel status. These changes were applied to all airplane types and operations at the school, and were subsequently written in the Flight Operations Manual.