Background
No record was found indicating the pilot received a weather briefing before departure, despite unfavorable weather in the vicinity. During ground communications, the pilot repeatedly struggled to understand and comply with instructions from clearance delivery, ground control, and departure control.
Flight Sequence
After takeoff, the pilot requested and received an IFR clearance. In the last five minutes of flight, radar data showed the airplane changing heading frequently—from 45 degrees to as much as 180 degrees about ten times—and oscillating in altitude between 4,500 feet MSL and 11,500 feet MSL. These altitude and heading changes were not directed by controllers.
Approximately three minutes before the accident, departure control asked the pilot if he had a problem. The pilot replied that he did and stated, "We're trying to get straight." One minute later, he said, "We're all right." Soon after, radar data indicated a loss of control. Radar and communications were lost, and an on-ground explosion was observed as the accident occurred.
Medical Findings
An FAA flight surgeon reviewed the pilot's medical records from within one year of the accident. The records showed the pilot had three physical conditions and was taking three separate prescriptions that would have prevented him from being medically qualified to pilot an aircraft.