Accident Overview
The airplane impacted the ocean following a departure from controlled cruise flight. No pre-accident anomalies were noted with any systems examined, and no distress calls or communications preceded or followed the upset.
Aircraft Behavior
According to the investigation, the airplane decelerated from 120 knots to approximately 60 knots while maintaining an altitude of 3,500 feet mean sea level (msl). It then descended at rates as high as 7,000 feet per minute, spiraling toward the ocean in a corkscrew manner before impact. This behavior could not be explained by any reasonable scenario in which the pilot, who held an airline transport pilot certificate and had accumulated 11,500 flight hours, was deliberately controlling the aircraft.
Pilot Medical Findings
The autopsy report on the 51-year-old pilot documented a condition known as left ventricular hypertrophy (LVH), characterized by a substantially thickened main heart chamber. Additionally, the pilot had moderate to severe coronary artery disease with evidence of at least one prior small heart attack. The combination of these conditions would have substantially increased the risk for sudden cardiac death. The investigation found no evidence that the pilot was aware of his heart disease.
Investigation Conclusion
Investigators determined that the pilot was likely unable to control the aircraft, an inability that can reasonably be explained by an incapacitating cardiac event. The source stated: 'The behavior of the aircraft cannot be explained by any reasonable scenario in which the 11,500-hour pilot was deliberately controlling the aircraft. Therefore, it seems likely that the pilot was unable to control the aircraft, an inability that can reasonably be explained by an incapacitating cardiac event.'