Accident Sequence
The airplane was cruising at Flight Level 280 when the instrument-rated pilot failed to contact air traffic control (ATC) following an assigned frequency change. Approximately 25 minutes later, while 30 miles east of the destination airport, the pilot established contact with ATC on a frequency other than the one assigned. He requested the instrument landing system (ILS) approach for his intended destination. The controller then instructed the pilot to descend to 8,000 feet and to expect vectors for the ILS approach. When the controller asked if everything was "okay," the pilot replied, "yes sir, everything is fine."
Shortly after, the controller observed the airplane initiating a descent. About two minutes later, the controller asked the pilot where he was headed, receiving a garbled response. The controller then instructed the pilot to stop his descent at 10,000 feet, followed by an instruction to stop the descent at any altitude. The pilot did not respond, and further attempts to contact him were unsuccessful.
The airplane subsequently impacted terrain in a heavily wooded area, approximately 17 miles from the destination airport. The aircraft disintegrated on impact, and both occupants sustained fatal injuries.
Investigation
The probable cause of the accident, as determined by the official investigation, was the pilot's failure to maintain control of the airplane for undetermined reasons during the descent to the destination airport.