What happened
During an instrument approach, the pilot was descending from 23,000 feet when radio communications were interrupted. Following an instruction to contact approach control, the aircraft ceased all radio contact. Radar tracking of the aircraft ended at 11,300 feet because of difficulties in receiving the radar signal. The loss of contact occurred near the location where the aircraft eventually struck the ground in a small valley.
Observers positioned on the western side of the valley reported seeing the aircraft flying at treetop level in an eastbound direction, clear of any cloud cover. However, the eastern side of the valley, where the impact occurred, was experiencing heavy rainfall at the time. The aircraft struck trees and terrain in this area.
Findings
Investigation of the wreckage revealed that all control surfaces of the aircraft were present at the site. The engines and propellers showed evidence suggesting they were under power at the moment of impact. The pilot had accumulated approximately 1,850 total flight hours and had recently finished both an instrument proficiency program and a 'Wings III' flight proficiency program within the previous two months. The aircraft had been maintained under a continuous maintenance program. Due to the condition of the remains, it was not possible to perform an autopsy or toxicological analysis. It was noted that the pilot had a family history of fatal heart attacks, involving a father, two uncles, and a cousin.