On November 10, 1993, at 1753 eastern daylight time, a Brady C. Bowermaster B-8M, N10343 was substantially damaged following a collision with terrain near Cowpens, South Carolina. The private pilot received serious injuries in the accident. The aircraft was being operated under 14 CFR Part 91 by the pilot. Visual meteorological conditions existed at the time, and no flight plan had been filed for the local personal flight. Witnesses reported that they observed the aircraft maneuvering around the airport. The pilot reported that the engine lost power while approaching for landing and that he autoratated and force landed the aircraft in forest terrain. The aircraft struck a group of trees near the side of the runway at the private sod airfield and crashed into the terrain. Post accident examination of the gyroplane revealed no evidence of mechanical failure of the engine. Fuel was found in the fuel tank and fuel system after the accident. The owner of the aircraft stated that the fuel tanks were susceptible to fuel sloshing and that it may cause momentary fuel starvation.