What happened
On 22 January 2023, an Airbus A350-1041, registration G-XWBL, was operating a commercial passenger flight at 36,000 feet over the North African coast. While the aircraft was in the cruise phase with the autopilot engaged and passenger seatbelt signs extinguished, it encountered a sudden period of turbulence.
During this event, a member of the cabin crew was moving toward the galley sink to dispose of a cup of tea. The intensity of the aircraft's motion caused the crew member to be lifted off the floor. Upon falling, the individual sustained serious injuries, specifically two pelvic fractures and a badly bruised shoulder. Additionally, a second crew member suffered a minor cut to the ankle caused by shards from the ceramic cup that shattered during the incident.
Following the event, the flight crew activated the seatbelt signs as a precaution and maintained them until the cabin was confirmed secure. After receiving medical advice, the commander decided to proceed to the destination, where the injured crew member was transported to a hospital.
The investigation
Investigators analyzed flight data recordings to reconstruct the turbulence event. The data revealed that the period of instability lasted approximately 20 seconds, during which vertical g-loading fluctuated between 0 G and +1.47 G. The aircraft's altitude shifted between 35,950 ft and 36,080 ft, with vertical speeds ranging from +1,100 ft/min to -1,460 ft/min.
Analysis also showed that the aircraft's speed briefly increased to M0.892. While this briefly exceeded the maximum operating Mach number (MMO1) of M0.89, the duration was less than one second, and the speed did not reach the threshold required to trigger an MMO warning. The autopilot remained active throughout the turbulence, and no structural load exceedances were recorded.