Accident Overview
While cruising at night under instrument flight rules (IFR) with the autopilot system engaged, a twin-engine aircraft struck the slope of a mountain located near Yakima. The wreckage was found a day later. The airplane was destroyed and the pilot was killed.
Flight Conditions
At the time of the accident, the aircraft was operating under IFR conditions at night. The autopilot system was active. The aircraft was approximately 10 miles off its intended course for an undetermined reason.
Official Findings
The probable cause of the accident, as determined by the investigation, was controlled flight into terrain. The aircraft was 10 miles off the intended course for an undetermined reason.