Narrative:

Approximately 20 mins into flight, as 4 coach flight attendants were preparing for beverage service, we encountered turbulence, causing 3 of us to impact with ceiling. Others also thrown about. Soon after, I called captain asking if it was safe to be up and asked him if it had been CAT. He said no, it appeared that we went between 2 thunderstorms and must have caught the gusts from one of them. He said nothing appeared on radar to warn him of the severity of turbulence. I noticed no other significant turbulence prior to this unexpected turbulence lasting approximately 30 seconds. Pilots and even 2 flight attendants in forward part of aircraft, seemed unaware of the extent to which we felt effects at aft of aircraft -- noticeably different from their perception.

Google
 

Original NASA ASRS Text

Title: B757 CABIN ATTENDANTS INJURED DURING BEVERAGE SVC PREPARATION WHEN ENTERING UNEXPECTED TURB.

Narrative: APPROX 20 MINS INTO FLT, AS 4 COACH FLT ATTENDANTS WERE PREPARING FOR BEVERAGE SVC, WE ENCOUNTERED TURB, CAUSING 3 OF US TO IMPACT WITH CEILING. OTHERS ALSO THROWN ABOUT. SOON AFTER, I CALLED CAPT ASKING IF IT WAS SAFE TO BE UP AND ASKED HIM IF IT HAD BEEN CAT. HE SAID NO, IT APPEARED THAT WE WENT BTWN 2 TSTMS AND MUST HAVE CAUGHT THE GUSTS FROM ONE OF THEM. HE SAID NOTHING APPEARED ON RADAR TO WARN HIM OF THE SEVERITY OF TURB. I NOTICED NO OTHER SIGNIFICANT TURB PRIOR TO THIS UNEXPECTED TURB LASTING APPROX 30 SECONDS. PLTS AND EVEN 2 FLT ATTENDANTS IN FORWARD PART OF ACFT, SEEMED UNAWARE OF THE EXTENT TO WHICH WE FELT EFFECTS AT AFT OF ACFT -- NOTICEABLY DIFFERENT FROM THEIR PERCEPTION.

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.