The airplane impacted a tree at approximately 1735 Pacific time. The Commercial pilot, who was the sole occupant, received fatal injuries, and the aircraft, which was being operated by AirPac Airlines, was destroyed by the impact and the post-crash fire. The Part 135 air cargo flight was being operated in visual conditions on an IFR flight plan. According to the Seattle ARTCC, the pilot was in cruise flight at 8000 feet msl when he reported that he did not have enough power to maintain altitude. The aircraft began to descend and the pilot told ATC he was diverting to Easton. About five minutes after the pilot advised ATC of the problem, the aircraft was seen turning final for Runway 27 at Easton. About one-half mile from the end of the runway, it impacted a conifer tree about 20 feet from its top, and descended into the terrain. After impacting the terrain, the wreckage erupted into intense flames.