DC9-50 PAX INJURED DURING DSCNT DUE TO TURB FROM TSTMS.

Narrative

PRIOR TO FLT; PAX NOTIFIED TO EXPECT SOME TURB ENRTE. WHEN DSCNT COMMENCED WX RADAR TURNED ON DUE TO TSTM IN OHIO VALLEY. PRIOR TO FL180; ANOTHER PA WAS MADE DIRECTING PAX TO FASTEN SEATBELTS AND TO EXPECT SOME LIGHT TURB DURING DSCNT INTO DTW. IMC AND LIGHT TURB ENCOUNTERED DURING DSCNT. I DIRECTED PNF TO ENSURE BOTH FLT ATTENDANTS WERE SEATED WITH HARNESSES ON. CONTINUING IN LIGHT TURB; RADAR SHOWED NOTHING MORE THAN RAIN -- NO STORM CELLS NOTED ON COURSE FOR STAR. DURING DSCNT; WE ENCOUNTERED SEVERAL MODERATE BUMPS. APPROX 30 SECONDS LATER; #2 FLT ATTENDANT CAME FORWARD TO INFORM US THAT A PAX (A NON REVENUE FLT ATTENDANT COMMUTING TO HER CREW BASE) HAD BEEN UP IN THE CABIN DURING THE MODERATE BUMPS AND SUSPECTED SHE HAD BROKEN HER ANKLE. #2 FLT ATTENDANT ADMINISTERED FIRST AID; AND I DIRECTED COMPANY OPS TO HAVE PARAMEDICS MEET THE FLT. REMAINDER OF DSCNT/APCH WAS UNEVENTFUL WITH LITTLE OR NO TURB. THERE IS AN ONGOING PROB WITH PAX IGNORING PA ANNOUNCEMENTS REGARDING TURB; AND DISREGARDING THE FASTEN SEATBELT SIGN. OF PARTICULAR CONCERN IS THAT A FLT ATTENDANT CHOSE TO IGNORE THE TURB AND WAS INJURED. SHE WAS NOT IN UNIFORM; WAS NOT PART OF THE CREW; AND HAD NO DUTIES IN THE CABIN. WE MUST CONTINUE TO STRESS TO ALL PAX THAT IT IS IMPOSSIBLE TO ACCURATELY FORECAST TURB 100% OF THE TIME; AND PA'S SHOULD BE HEEDED.