On March 16, 1996, at 1105 central standard time, an Enstrom F-28A, N9574, registered to and operated by a private owner under Title 14 CFR Part 91, was substantially damaged during a forced landing near Killeen, Texas. The commercial helicopter pilot and one passenger were not injured; however, one passenger sustained minor injuries. Visual meteorological conditions prevailed for the local flight that originated at Killeen Municipal Airport near Killeen, Texas, approximately 26 minutes before the accident. No flight plan was filed. The pilot reported in the Pilot/Operator Aircraft Accident Report that during his preflight of the helicopter he knew that the fuel tanks were not full, but they "seemed adequate." He estimated that the two 15 gallon tanks were about "3/4 of a tank capacity." The pilot reports that he performed the "walkaround" of the helicopter while "talking about several items to individuals present." The pilot further reports that "a normal start, warm-up and rotor engagement" were made before a "hovering demonstration and short flight to the west along highway 190 and return to Killeen airport." The helicopter was last flown the night before, by another pilot. He reported to a FAA inspector that he thought the fuel tanks were only "1/4 full" at the termination of that flight. The Pilot's Owners Handbook for the Enstrom F-28A revealed a fuel consumption of approximately 19.1 gallons per hour at 100%. Fuel consumption at 75% power, is approximately 12.3 gallons per hour. The pilot states that after he returned to Killeen Airport, two passengers were boarded and he began a second flight identical to the first. He performed a hovering demonstration, and, then flew west along highway 190. Approximately 3 miles later, the engine began to "run rough." Subsequently the engine "quit completely" and the pilot autorotated to the rough and uneven ground. The ensuing hard landing damaged the main rotor blade, tailboom, tail rotor gearbox, tail rotor, tail skid, and left rear diagonal skidtube. Post-crash examination of the aircraft by a FAA inspector revealed no evidence of fuel in the fuel tanks.