On June 2, 2007, about 1315 mountain daylight time, an amateur built Brook Lancair IV-P, N401PT, made a forced landing following a loss of engine power at Parowan Airport, Parowan, Utah. The private pilot operated the airplane under the provisions of 14 CFR Part 91. The pilot and single passenger were not injured, and the airplane was substantially damaged. Visual meteorological conditions prevailed, and an IFR flight plan had been filed. The flight originated at Deer Valley Airport, Phoenix, Arizona, at 1100, and was en route to Hailey, Idaho. The pilot reported to the National Transportation Safety Board investigator that he was about 1 hour 15 minutes into the flight, and the airplane was cruising at 26,000 feet, when the turbo prop engine quit with white smoke coming out of the exhaust. About a minute before he had observed "splats" of moisture on the windscreen. He performed an emergency descent to 15,000 feet, and at 12,500 feet attempted an engine restart. The restart attempt was unsuccessful. He proceeded to the nearest airport, which was Parowan Airport. He circled and performed a no-power approach to runway 04. The airplane crossed the runway threshold at 120 knots, floated, and touched down at mid field. After touchdown, the airplane continued down the runway, off the end, and into terrain and a fence. The airplane came to rest with the landing gear collapsed. Federal Aviation Administration inspectors examined the airplane at the Parowan Airport. The inspectors determined that the wing vents were clear of debris; the center fuel tank vent was operational; the fuel boost pumps were energized and operated; the fuel system was clean; the engine igniters operated; the engine controls were properly connected to the engine; the engine rotated freely with no binding; and the engine driven fuel pump was operationally checked to function. The Pilot Operating Handbook states that an engine relight was possible below 13,000 feet mean sea level, and below 160 knots of airspeed. The pilot could not recall what his airspeed was when he attempted the engine restart. The airplane was not equipped with any type of engine inlet anti-ice or deicing equipment. The pilot did state that he had been in and out of moisture while at his 26,000 feet cruising altitude, but there had been no ice buildup on his wings or windscreen. A technical representative for Lancair stated that a 3/4 blockage of the cowling NACA induction scoop might be enough to starve the engine of air and induce a flameout.