On July 23, 2001, at 0933 eastern daylight time, a homebuilt Lancair IV-P, N488SD, was substantially damaged during a forced landing in Fryeburg, Maine. The certificated private pilot/builder and the passenger were not injured. Visual meteorological conditions prevailed, and a visual flight rules flight plan was filed for the personal flight conducted under 14 CFR Part 91. The pilot/builder reported that he had departed from Lewiston, Maine, and was en route to Buffalo, New York, with a final destination of Oshkosh, Wisconsin. About 10 minutes after departure, he was climbing through 8,000 feet for 14,500 feet, when the manifold pressure, which had been about 34 inches, dropped to about 15 inches. He checked his GPS for the closest airport, which was Fryeburg, about 12 nautical miles to the north. He turned toward the airport and set up a descent at 120 KIAS. He said that he did not declare an emergency at that time and thought he would be able to make the airport. As the airplane descended through 3,000 feet, the manifold pressure, which had been steadily decreasing, decreased to 4 inches. The pilot reported that at that point he retarded the propeller control to its maximum pitch position to reduce drag, and reduced his airspeed to about 100 KIAS. The pilot/builder positioned the airplane for a straight-in approach to runway 32. As the airplane neared the runway, he decided to hold the landing gear due to the lower-than-anticipated altitude of the airplane. When he did extend the landing gear, there was insufficient time to complete the extension, and the airplane touched down about 100 feet short of the runway with the landing gear only partially extended. The airplane then slid onto the runway and came to a stop. According to an inspector from the Federal Aviation Administration (FAA), the composite blades of the propeller were broken off, the bottom of the fuselage was scraped, and there was a fuel spill from where the right wing fuel tank was broken open. The remains of a paper towel were found in the turbocharger and intercoolers. The pilot reported that he had just completed his phase 1 flight time requirements after building the airplane, and had inspected it. During the inspection, several people, some of whom were not rated mechanics, assisted. The engine cowling had been removed, and paper towels were used as wipes on various parts of the engine and airplane. Several paper towels were reported to be lying loose on the ground at the completion of the inspection. In addition, the pilot/builder told the FAA inspector that a paper towel had inadvertently been left on the top of the engine. The FAA inspector also noted that there was a 5-inch by 10-inch opening in the back of the engine, which allowed unfiltered air into the air intake manifold. The accident flight was the first flight following the inspection.