Flight Descent and Turbulence Encounter
The captain initiated a descent from flight level (FL) 290 and illuminated the fasten seatbelts sign. As the aircraft reached FL 240, the air became choppy. Below FL 240, flight attendants were notified to clean up and be seated, and a passenger announcement warned of possible turbulence. At approximately FL 230, the flight attendants were instructed to be seated.
At FL 220, the aircraft encountered severe turbulence lasting about five seconds. Two to three minutes later, a second episode of severe turbulence, also lasting five seconds, occurred.
Injury Incident
During the second turbulence event, one flight attendant stopped on her way to her seat to address a passenger who had not fastened his seatbelt. While she was instructing the passenger, the aircraft encountered severe turbulence, causing her to be thrown about the cabin. The other flight attendant (referred to as "A" in the report) notified the flight crew that the second flight attendant ("B") had been injured.
Response and Aftermath
The captain instructed the "A" flight attendant to help secure the "B" flight attendant in her seat and then return to her own seat as soon as possible. Air traffic control was notified of the severe turbulence and that medical assistance would be needed upon arrival. Company flight operations in Fresno were also informed.
Upon arrival at the gate, all passengers deplaned without further incident. Paramedics boarded the aircraft and attended to the injured flight attendant. Subsequent X-rays revealed that she had sustained a fractured ankle.