Incident Overview
An airplane experienced moderate to severe turbulence while cruising at 35,000 feet. The turbulence resulted in injuries to two flight attendants: one sustained serious injuries, and another suffered minor injuries.
Sequence of Events
Approximately two hours before landing, the flight crew contacted the flight attendants to inform them that turbulence was expected, based on air traffic control ride reports. The crew instructed the attendants to secure the cabin and galleys. The flight crew also reported that the airplane had been slowed to Mach 0.78 when the turbulence was encountered.
One flight attendant, who was seated in seat 34C, did not fasten her seatbelt immediately. During the turbulence encounter, she was lifted into the air, struck the overhead compartment, then fell onto an armrest before landing on the floor.
Injuries
One flight attendant sustained serious injuries, and another flight attendant sustained minor injuries as a result of the turbulence. The exact nature of the injuries is not specified in the report.
Aircraft and Flight Context
The incident occurred during cruise flight at an altitude of 35,000 feet. No information about the aircraft type, registration, operator, date, or route is provided in the source material. The flight crew's decision to slow the aircraft to Mach 0.78 was noted, and they had received prior turbulence warnings from ATC ride reports.
Conclusion
The source material does not assign a probable cause for the turbulence encounter. It simply documents the events and resulting injuries.