What happened
During a period of cruise flight, the aircraft encountered a level six thunderstorm while traveling across the Atlantic Ocean. During this encounter, the pilot communicated that the onboard gyroscope had malfunctionous. Following this equipment failure, the aircraft initiated a left-hand turn and subsequently vanished from radar tracking.
After a search period of approximately 48 days, the wreckage and all occupants were located on the ocean floor. The investigation of the debris indicated that the aircraft had experienced an in-flight breakup. While portions of the wreckage were found, the tail section and the outboard portions of both wings were not recovered from the site.
Findings
Evidence from the wreckage showed that the pneumatic system of the aircraft had been destroyed. Records from Flight Service Stations (FSS) indicate that the pilot had received a weather briefing regarding the meteorological conditions along the intended flight path prior to the incident.