On September 30, 1993, at 1435 eastern daylight time, a Cessna 150, N1141Z, was substantially damaged following a collision with terrain during a forced landing near Sylvania, Georgia. The student pilot was not injured in the accident. The aircraft 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 instructional flight. The flight departed Winnsboro, South Carolina, and was destined for Sylvania, Georgia. According to the pilot, the flight departed Winnsboro at 1100 hours with four hours of fuel on board. Approximately three and one half hours into the flight, and three miles north of the destination airport, the airplane lost engine power. The pilot selected an open corn field and executed an emergency landing; during the final approach, the left wing struck the ground. During the subsequent aircraft examination, two gallons of fuel were recovered from the fuel system. According to the flight manual for the Cessna 150, 3.5 gallons of the total fuel capacity are unusable. Additionally, the engine was functionally checked with the existing fuel quantity and aircraft systems. The wreckage examination failed to disclose a mechanical malfunction or component failure.