On August 12, 1998, approximately 1600 Pacific daylight time, a Six/Huber RV-6 experimental-category airplane, N26CH, was substantially damaged in a hard forced landing following a complete loss of engine power at the Roseburg Regional Airport, Roseburg, Oregon. Neither the private pilot-in-command nor his sole passenger were injured in the occurrence. Visual meteorological conditions were reported at Roseburg at 1553. The flight, which had just departed Roseburg bound for Medford, Oregon, was operated under 14 CFR 91, and the FAA did not report any record of a flight plan being filed for the flight. The pilot reported that engine start, taxi, and pretakeoff run-up were normal, and that taxi was accomplished on the right fuel tank. The pilot reported he then took off on Roseburg runway 34 (4,600 feet long; asphalt; airport elevation 525 feet.) Van's Aircraft, the RV-6 kit manufacturer, lists the aircraft's takeoff distance at 1,600 pounds gross weight with a 160-horsepower engine as 525 feet. The pilot stated the takeoff was uneventful until about 450 feet above ground level, at which point a total loss of power occurred during a left turn. The pilot stated he then checked his magneto switches and auxiliary fuel pump on, then concentrated on gliding to the airport, turning downwind adjacent to the runway. The pilot stated the engine windmilled throughout this sequence of events. The pilot reported he then touched down on the grass next to the runway and slid onto the runway. The aircraft's left fuel tank was damaged in the forced landing, and was noted to be leaking after the accident. The pilot gave the aircraft's engine type as a Ken Hatfield Enterprises O-340-A1AKH, a carbureted reciprocating engine rated at 170 horsepower. The pilot reported he filled up in Medford prior to flying a 0.4-hour flight from Medford to Roseburg using the right tank. The pilot stated that 30 gallons of fuel was on board at the last takeoff. Van's Aircraft gives the fuel capacity of the RV-6 as 38 gallons. According to the aircraft records, the engine received a major overhaul on May 27, 1992, at 2,000 hours total time, and the aircraft was manufactured on January 10, 1993. The pilot furnished documentation indicating he had last performed a condition inspection on the aircraft on March 7, 1998, at 688.7 hours total time, approximately 38 flight hours before the accident. The aircraft records indicated that on that date, the pilot noted the following engine discrepancies: elevated amount of chips in the filter; idler shaft loose; and 0.012 inches play at exhaust valve guides of number 3 and 4 cylinders. The corrective action recorded included installation of a new idler shaft, replacement of valve guides, reaming to 0.006 inches play, and resurfacing the valve seat. A 1553 Roseburg weather observation reported the temperature as 93 degrees F and the dewpoint as 55 degrees F. According to FAA carburetor ice hazard prediction data, this combination of temperature and dewpoint does not pose a hazard of serious carburetor icing. The NTSB and FAA did not examine the engine following the accident, and the pilot did not report any specific findings of a mechanical nature regarding the power loss to the NTSB.