What happened
On September 27, 2002, an All Nippon Airways flight operating a Boeing 767-300, registration JA8274, was on final approach to Kochi Airport when it encountered extreme atmospheric instability. The aircraft, which had departed from Tokyo International Airport, was descending through 2,600 feet approximately 16 nautical miles southeast of the airport when it was struck by sudden, violent motions.
Flight data recorder analysis shows that between 20:25:02 and 20:25:03, the aircraft experienced a significant vertical acceleration of 1.6G upward and a lateral acceleration of 0.4G to the left. These rapid fluctuations in altitude and attitude caused the aircraft to shake violently, leading to two serious injuries and one slight injury among the 288 passengers on board. Following the encounter, the pilot initiated a missed approach at approximately 1,700 feet due to continued moderate to severe turbulence. The crew eventually entered a holding pattern to wait for the weather to clear before successfully landing at Kochi Airport later that evening.
The investigation
The investigation examined flight data recorder (DFDR) archives, air traffic control radio communications, and weather radar imagery. Investigators also analyzed the physical accelerations experienced in the aft cabin by studying seat-specific motion. Furthermore, the investigation reviewed the communication between the flight crew and ground-based dispatchers regarding weather updates and the accuracy of the information provided regarding convective activity (echoes) near the destination.