B737-700 FLT CREW ENCOUNTERS SEVERE TURB AT FL370 NEAR LBL VOR. FLT ATTENDANT INJURIES RESULT IN DIVERSION.

Narrative

WE WERE CRUISING AT FL370 A FEW MI W OF LIBERAL VOR; KS. WE WERE IN CLOUDS WITH THE SEATBELT SIGN ON. THE RADAR SHOWED AN ECHO 80 MI S OF OUR COURSE; 20 MI LONG AND 5 MI WIDE JUST N OF AMA. NO OTHER ECHOES WERE SHOWING ON THE RADAR. I SAW CLR SKIES FOR A FEW SECONDS ON THE R SIDE OF THE ACFT AND AT THE SAME TIME I SAW A LARGE BUILDUP DIRECTLY IN FRONT OF US. AS I WAS POINTING THIS OUT TO THE CAPT; WE FLEW INTO THE TOPS OF THE CLOUDS WHERE WE ENCOUNTERED SEVERE TURB AND SMALL HAIL. WE HAD UP- AND DOWNDRAFTS THAT CAUSED US TO LOSE 500 FT OF ALT AND WE HAD AIRSPD FLUCTUATIONS OF UP TO MACH .84 (275 KTS) AND DOWN TO 225 KTS. NORMAL CRUISE SPD WAS MACH .78. WE EXITED THE CLOUDS 45-60 SECONDS LATER INTO CLR SKIES AND SMOOTH AIR. WE NOTIFIED CTR OF OUR ALTDEV AND FLT CONDITIONS PRIOR TO AND DURING THE EVENT. THE ONLY AREA OF WX THAT SHOWED ON RADAR WAS S OF US AND WE WERE ON THE UPWIND SIDE OF THE WX. PAST EXPERIENCE HAS SHOWED THAT THIS WAS THE BEST PLACE FOR US TO BE. WE HAD NO WARNING PRIOR TO THE EVENT WITH OTHER ACFT IN THE AREA RPTING TURB NO GREATER THAN LIGHT. AFTER WE REGAINED OUR ALT; I CALLED BACK TO SEE IF THE FLT ATTENDANTS WERE OK. WE FOUND OUT THAT 2 OF OUR FLT ATTENDANTS WERE STANDING IN THE AFT GALLEY WHEN THE EVENT OCCURRED. ONE OF THEM SUFFERED A BROKEN ANKLE. AFTER WE CALLED MEDLINK AND DISPATCH; WE ELECTED TO DIVERT. NO ONE ELSE WAS INJURED AND THE REST OF THE FLT WAS UNEVENTFUL. I CAN'T THINK OF ANYTHING THAT WE COULD HAVE DONE DIFFERENTLY THAT WOULD HAVE PREVENTED THIS FROM HAPPENING. SUPPLEMENTAL INFO FROM ACN 619491: WE ASKED ATC FOR A DEV TO THE R OF COURSE AND GOT IT. WE BROKE OUT INTO THE CLR AFTER ABOUT 45-60 SECONDS. WE ADVISED ATC OF OUR SEVERE TURB ENCOUNTER AND TOLD THEM THAT WE HAD SEEN NOTHING ON RADAR AND THEY AGREED THAT THEY HAD SEEN NOTHING ON THEIR RADAR. DURING THE ENCOUNTER WE ALSO EXPERIENCED EITHER HVY RAIN OR SMALL HAIL. ATC STARTED VECTORING OTHER ACFT AWAY FROM THE AREA. WHILE WE WERE LOOKING UP RADIO FREQS FOR DISPATCH; THE 'A' FLT ATTENDANT CONTACTED US AND TOLD US THAT ANOTHER FLT ATTENDANT WAS INJURED AND THAT THEY WERE LOOKING FOR MEDICAL PERSONNEL ON BOARD. 2 NURSES WERE ON BOARD AND ASSISTED WHILE HE TALKED TO THE DOCTOR ON MEDLINK. THE DOCTOR DECIDED WE SHOULD CONTINUE ON TO OUR DEST. WE WERE ABOUT TO CALL DISPATCH AGAIN WHEN THEY CALLED US. THE DISPATCHER AND I DECIDED TO DIVERT TO THE NEAREST SUITABLE ARPT BECAUSE OF THE FLT ATTENDANT INJURY. THE CLOSEST ARPT WAS ABOUT 95-100 MI TO THE E OF OUR POS. I WROTE UP THE ACFT FOR THE ENCOUNTER WITH SEVERE TURB. AFTER COMPANY MAINT INSPECTED THE ACFT; AND A REPLACEMENT FLT ATTENDANT WAS FOUND; WE CONTINUED ON.