Incident Overview
A flight encountered severe turbulence during its initial descent into an unspecified destination. The aircraft had been experiencing moderate chop for some time, with the seat belt sign illuminated for approximately 20 minutes. All passengers were secured in their seats. Cabin crew had just completed a beverage service and were stowing galley equipment when the turbulence occurred.
As the aircraft descended through 17,500 feet, a single severe jolt of turbulence was experienced. Two cabin crew members were standing in the aft galley at the time. One crew member was able to grab a handhold, while the other was thrown against the ceiling and then back to the floor. The latter sustained a compound fracture of one ankle, which required surgical repair. The second crew member was treated at a hospital for soft tissue injuries and subsequently released.
Weather Conditions
Review of weather reports indicated that SIGMET Papa 13 was issued at 221656, forecasting moderate to occasional severe turbulence in the southern portions of California below 18,000 feet. Additionally, Center Weather Advisories 01 and 02 were in effect for the time and location of the encounter, predicting moderate to occasional severe turbulence below 22,000 feet.
The dispatch weather package provided to the flight crew at Chicago was reviewed. The date/time group for the package preparation was 221501, prior to the issuance of SIGMET Papa 13 and both Center Weather Advisories. No SIGMETs were noted for the terminal portions of the flight.
Conclusion
The injuries resulted from the severe turbulence encounter during descent. No further details about the aircraft, flight number, or operator were provided.