Incident Overview
At 1445 MDT, a 60-year-old pilot departed on a routine VFR repositioning flight that he had frequently flown before. After takeoff, he leveled the aircraft at 9500 feet on a direct course toward the destination.
Sequence of Events
While en route at about 1515, the aircraft began a shallow oscillatory descent when it was approximately 28 miles from the Black Mountain Range. Subsequently, the aircraft collided with a ridge about 1 mile from Black Mountain Peak while in a wings-level attitude at an elevation of about 8500 feet.
Weather and Environmental Conditions
The weather at the time of the accident was VFR with only scattered clouds and 15 miles visibility.
Aircraft Examination
An examination of the wreckage revealed no evidence of a preimpact part failure or malfunction. The aircraft was equipped with an ARNAV-20 LORAN unit and a Century IIB autopilot. The autopilot had no altitude hold function, but its mode selector was found positioned to the 'HDG' position. Additionally, the elevator trim was found near the neutral position.
Pilot Examination
Pathological and toxicological examinations revealed no indication of a physiological problem. The possibility of the pilot falling asleep or becoming incapacitated could not be determined.