On December 18, 2012, about 0002 mountain standard time (MST), a Beech B100, N499SW, collided with trees at Libby, Montana. Stinger Welding was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The noncertificated pilot and one passenger sustained fatal injuries; the airplane sustained substantial damage from impact forces. The cross-country personal flight departed Coolidge, Arizona, about 2025 MST on December 17th, with Libby as the planned destination. Visual meteorological conditions prevailed at the nearest official reporting station of Sandpoint, Idaho, 264 degrees at 46 miles, and an instrument flight rules (IFR) flight plan had been filed. The Federal Aviation Administration (FAA) reported that the pilot had been cleared for the GPS-A instrument approach procedure for the Libby Airport. The clearance had a crossing restriction of 10,700 feet at the PACCE intersection, which was the initial approach fix for the GPS-A approach. The pilot acknowledged that clearance at 2353. At 2359, the airplane target was about 7 miles south of the airport; the pilot reported the field in sight, and cancelled the IFR flight plan. A police officer reported that he observed an airplane fly over the city of Libby, which was north of the airport; the airplane then turned toward the airport. The officer went to the airport to investigate, but observed no airplane. He noted that it was foggy in town, but the airport was clear. He also observed that the rotating beacon was illuminated, but not the pilot controlled runway lighting. When the pilot did not appear at a company function at midday on December 18, they reported him overdue. The Prescott, Arizona, Automated Flight Service Station (AFSS) issued an alert notice (ALNOT) at 1102 MST; the wreckage was located at 1835.