On July 19, 1994, approximately 1300 Pacific daylight time, a Kaman HH43F, N324WN, sustained substantial damage when it collided with terrain during a forced landing after a loss of power while engaged in helicopter logging operations near John Day, Oregon. The commercial pilot, who was the sole occupant of the aircraft, was seriously injured. There was no flight plan filed for the flight, which was conducted in visual meteorological conditions. The pilot stated that the engine "grenaded" in flight. He attempted an autorotation into trees, as he was over a select cut with no unobstructed place to land. He said that he flew around several larger trees in an attempt to keep the rotor blades intact as long as possible. At about 40 feet elevation, with no alternatives he pulled pitch to check his descent rate, settling into the trees. Inspection by FAA inspectors noted that the number two compressor wheel failed, and the entire wheel came out of the aircraft.