What happened
During a personal instrument flight, the pilot encountered thunderstorms while operating an aircraft over Tyringham, Massachusetts. Prior to the flight, the pilot had obtained a preflight weather briefing and was subsequently advised of a significant meteorological information (SIGMET) during the flight.
The investigation
Due to the fragmentation of the wreckage, control continuity could not be established. However, investigators found that the separation signatures were consistent with the control surfaces being installed and operational at the time of the break-up. An examination of the airframe, flight controls, and engine revealed no mechanical anomalies.
Review of air traffic control (ATC) data indicated that a relief controller had been briefed to turn the aircraft due to weather. Despite a light workload and very little traffic, the relief controller failed to issue necessary weather information or initiate a flight deviation around known and clearly observed weather.
Findings
- The pilot encountered thunderstorms during the flight.
- A relief air traffic controller failed to provide weather updates or direct a deviation from observed weather.