Accident Summary
On Saturday, March 26, 2022, Japan Airlines Co., Ltd. flight 669, a Boeing 767-300 registered as JA603J, departed Tokyo International Airport for Oita Airport. The aircraft carried 70 persons: the pilot in charge, seven crew members, and 62 passengers. At approximately 17:35 JST, while cruising at an altitude of about 8,500 meters (FL280) over Nakatsugawa City, Gifu Prefecture, the aircraft encountered turbulence. A flight attendant fell and suffered a sacral fracture, classified as a serious injury.
Flight Details
The aircraft took off at 17:15 JST. The pilot in charge (PIC) occupied the left seat as pilot monitoring, and the first officer served as pilot flying. During the pre-flight briefing, the PIC informed the flight attendants that turbulence was expected during climb and intermittently during cruise. The aircraft reached FL280 about 10 minutes after takeoff. The belt sign was turned off after the PIC determined that in-flight service could be provided, as the turbulence encountered during cruise was less than TB2 intensity.
Turbulence Encounter
At approximately 17:30, the aircraft received a pilot report (PIREP) from another aircraft encountering TB4 turbulence about 120 nautical miles ahead. The PIC and FO observed weak radar echoes about 100 nm ahead and were planning a avoidance maneuver. Suddenly, the aircraft experienced vertical shaking of TB4 class. The PIC immediately turned on the fasten seat belt sign. Flight attendant A, returning to the aft galley after stowing a cart, was lifted into the air and fell onto her buttocks before reaching the galley bar. The chief purser noted a sudden "thump" downward. After the turbulence, all flight attendants stowed carts and took their seats. The flight attendant did not report pain at that time, and the chief purser initially reported no injuries.
Aftermath
The flight continued to Oita Airport and then operated a return flight. After the flight, flight attendant A's legs gradually became immobile, and she reported to the company that she could not safely fly the next day. She visited medical facilities from March 26 to March 28, and was diagnosed with a sacral fracture. The aircraft sustained no damage. The digital flight data recorder showed vertical acceleration changes from about 1.0G to 1.26G, then to -0.02G, and back to 1.28G within seconds before the accident.
Investigation
The Japan Transport Safety Board (JTSB) investigated the accident. The report details the flight history, crew statements, and DFDR data, but does not assign a probable cause.