Narrative:

While cruising at FL330, aircraft encountered severe turbulence and lost several hundred ft of altitude causing injuries to 2 F/a's and 1 passenger. We were deviating WX on a route suggested by ATC and our own flight dispatcher. We also agreed with their suggestions as we had a good picture on our airborne radar. Approximately 10 mins prior to encounter, we had been visibility, but at actual time of encounter we were IFR in cirrus type clouds. At time of encounter we were approximately 25 mi from the nearest contouring cell as depicted on radar. We immediately informed ATC of the severe turbulence and altitude deviation. Also called our flight dispatcher with same information. Since we were in clouds and radar showed us to be on a clear path, we can only assume we encountered a wind shear situation or flew into a rapidly developing buildup that did not contain enough moisture to give a return on our radar. The ATC controllers and our dispatcher were providing the best information available and I thought we were operating in a safe manner, considering the information available to us and the equipment we were using. Callback conversation with reporter revealed the following: reporter did not have much to add to original report, except to restate the fact that the turbulence was totally unexpected. As surmised, the passenger that was slightly hurt was in the blue room while the seat belt sign was on. PIC did state that he thought that the color radar that was on board did not paint the smaller cells and that might have had a bearing on the incident. No FAA involvement. Company was sent a report.

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Original NASA ASRS Text

Title: SEVERAL INJURIES SUSTAINED AS ACR MLG ENCOUNTERS SEVERE AIR TURBULENCE WHILE DEVIATING AROUND TSTM ACTIVITY.

Narrative: WHILE CRUISING AT FL330, ACFT ENCOUNTERED SEVERE TURB AND LOST SEVERAL HUNDRED FT OF ALT CAUSING INJURIES TO 2 F/A'S AND 1 PAX. WE WERE DEVIATING WX ON A RTE SUGGESTED BY ATC AND OUR OWN FLT DISPATCHER. WE ALSO AGREED WITH THEIR SUGGESTIONS AS WE HAD A GOOD PICTURE ON OUR AIRBORNE RADAR. APPROX 10 MINS PRIOR TO ENCOUNTER, WE HAD BEEN VIS, BUT AT ACTUAL TIME OF ENCOUNTER WE WERE IFR IN CIRRUS TYPE CLOUDS. AT TIME OF ENCOUNTER WE WERE APPROX 25 MI FROM THE NEAREST CONTOURING CELL AS DEPICTED ON RADAR. WE IMMEDIATELY INFORMED ATC OF THE SEVERE TURB AND ALT DEVIATION. ALSO CALLED OUR FLT DISPATCHER WITH SAME INFO. SINCE WE WERE IN CLOUDS AND RADAR SHOWED US TO BE ON A CLR PATH, WE CAN ONLY ASSUME WE ENCOUNTERED A WIND SHEAR SITUATION OR FLEW INTO A RAPIDLY DEVELOPING BUILDUP THAT DID NOT CONTAIN ENOUGH MOISTURE TO GIVE A RETURN ON OUR RADAR. THE ATC CTLRS AND OUR DISPATCHER WERE PROVIDING THE BEST INFO AVAILABLE AND I THOUGHT WE WERE OPERATING IN A SAFE MANNER, CONSIDERING THE INFO AVAILABLE TO US AND THE EQUIP WE WERE USING. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR DID NOT HAVE MUCH TO ADD TO ORIGINAL RPT, EXCEPT TO RESTATE THE FACT THAT THE TURB WAS TOTALLY UNEXPECTED. AS SURMISED, THE PAX THAT WAS SLIGHTLY HURT WAS IN THE BLUE ROOM WHILE THE SEAT BELT SIGN WAS ON. PIC DID STATE THAT HE THOUGHT THAT THE COLOR RADAR THAT WAS ON BOARD DID NOT PAINT THE SMALLER CELLS AND THAT MIGHT HAVE HAD A BEARING ON THE INCIDENT. NO FAA INVOLVEMENT. COMPANY WAS SENT A RPT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.