What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Encountered cat enroute at FL350. Diverted to rno. Flight attendant broke an ankle. 7 passengers injured. (.4)the flight encountered sever clear air turbulence en route at flight level 350. There were no reports of clear air turbulence from other pilots nor was it forecasted. The seat belt signs were off at the time. A review of the flight recorder data indicated that, for the period involved, vertical acceleration (nz) varied from +1G to +1.5G to -0.07G to +1.3G to +0.86G over a 6-second period. The recorded data also indicated that atmospheric stability at flight level 350 during the several minutes prior to turbulent onset was such that little or no warning was given to the flight crew of the impending turbulent conditions. (-23) enroute seattle to las vegas @ 35,000 feet in calm air. Suddenly hit a pocket of extreme clear air turbulence approximately 30 miles north west of mustang VOR. Diverted to Reno Tahoe international airport. One serious injury, flight attendant ankle broken, all other injured were examined and released.
As the FAA filed it
ENCOUNTERED CAT ENROUTE AT FL350. DIVERTED TO RNO. FLIGHT ATTENDANT BROKE AN ANKLE. 7 PASSENGERS INJURED. (.4)THE FLIGHT ENCOUNTERED SEVER CLEAR AIR TURBULENCE EN ROUTE AT FLIGHT LEVEL 350. THERE WERE NO REPORTS OF CLEAR AIR TURBULENCE FROM OTHER PILOTS NOR WAS IT FORECASTED. THE SEAT BELT SIGNS WERE OFF AT THE TIME. A REVIEW OF THE FLIGHT RECORDER DATA INDICATED THAT, FOR THE PERIOD INVOLVED, VERTICAL ACCELERATION (NZ) VARIED FROM +1G TO +1.5G TO -0.07G TO +1.3G TO +0.86G OVER A 6-SECOND PERIOD. THE RECORDED DATA ALSO INDICATED THAT ATMOSPHERIC STABILITY AT FLIGHT LEVEL 350 DURING THE SEVERAL MINUTES PRIOR TO TURBULENT ONSET WAS SUCH THAT LITTLE OR NO WARNING WAS GIVEN TO THE FLIGHT CREW OF THE IMPENDING TURBULENT CONDITIONS. (-23) ENROUTE SEATTLE TO LAS VEGAS @ 35,000 FEET IN CALM AIR. SUDDENLY HIT A POCKET OF EXTREME CLEAR AIR TURBULENCE APPROXIMATELY 30 MILES NORTH WEST OF MUSTANG VOR. DIVERTED TO RENO TAHOE INTERNATIONAL AIRPORT. ONE SERIOUS INJURY, FLIGHT ATTENDANT ANKLE BROKEN, ALL OTHER INJURED WERE EXAMINED AND RELEASED.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.