Flight Details
On 22 November 2017, EVA Air flight BR056, a Boeing B777-300ER with registration B-16718, was operating a scheduled passenger service from Taiwan Taoyuan International Airport to Chicago O'Hare International Airport. The aircraft carried 3 pilots, 15 cabin crew, and 181 passengers, totaling 199 occupants.
Event Sequence
The flight departed Taoyuan at 1215 UTC and reached cruising altitude of 31,000 feet at 1238 UTC. At 1244 UTC, it entered the Fukuoka Flight Information Region. At 1310 UTC, Fukuoka Area Control Center cleared the flight to proceed from MELEN to IMPAL waypoint. Soon after, other aircraft reported moderate to severe turbulence on the M750 airway near MADOG waypoint. The controller relayed this to BR056. The crew briefly discussed, turned on the seatbelt sign, and made an announcement for all occupants to be seated. As the aircraft approached MADOG, about 42 nautical miles east-northeast of Miyazaki Airport over the sea, it entered turbulence with irregular vibrations. The crew adjusted speed to Mach 0.82; autopilot and autothrottle remained engaged. According to flight data, turbulence lasted about 2 minutes. Vertical acceleration ranged from -0.13g to +1.68g, vertical speed fluctuated between -300 and +600 feet per minute, and bank angle varied up to ±5 degrees.
Injuries and Damage
The turbulence resulted in injuries: 3 passengers and 6 cabin crew sustained minor injuries, and 2 cabin crew members suffered serious injuries (fractures and spinal injury). No injuries among the flight crew. The aircraft was not damaged. No other damage occurred.
Post-Event Actions
After exiting turbulence, the crew advised air traffic control and inquired about cabin conditions. The purser initially reported 3 passengers injured; flight attendants were busy securing the cabin. About 40 minutes later, the purser informed the captain that 8 cabin crew members were also injured. The captain consulted the company doctor, who advised that none required immediate medical attention. The crew, determining the aircraft systems were normal, continued to Chicago, landing safely at 0038 UTC on 23 November 2017.
Investigation Findings
The investigation found that the aircraft encountered severe turbulence based on flight data (vertical acceleration peak 1.68g, eddy dissipation rate >0.7). The cabin crew were in meal service when the turbulence warning was received; they could not secure the meal carts and seat themselves in time, leading to injuries from being struck by carts. The report also identified that the airline's cabin crew manual lacked procedures for turbulence during meal service, and that the pilot reporting system was not fully utilized.