Narrative:

The B77 flight is a scheduled air carrier operation from london (heathrow) to ewr. We encountered unexpected moderate clear air turbulence at approximately FL300 climbing to FL310 that lasted 5-10 seconds. Flight attendants had been released to start their service climbing through 13000 ft. The flight was clear of all clouds and was quite smooth during the entire climb from 13000 ft to the altitude of the encounter. The seatbelt sign did in fact remain on for the entire flight up to the incident and the subsequent return to heathrow. There were absolutely no indications of any turbulence in our area of operations. Several flight attendants were injured during this encounter. We returned to london after it was obvious to us the nature and severity of their injuries.

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Original NASA ASRS Text

Title: B777 NEARING TOP OF CLB FROM HEATHROW EXPERIENCES UNEXPECTED CLR AIR TURB. FLT ATTENDANTS INJURED. FLT RETURNS TO EGLL.

Narrative: THE B77 FLT IS A SCHEDULED ACR OP FROM LONDON (HEATHROW) TO EWR. WE ENCOUNTERED UNEXPECTED MODERATE CLR AIR TURB AT APPROX FL300 CLBING TO FL310 THAT LASTED 5-10 SECONDS. FLT ATTENDANTS HAD BEEN RELEASED TO START THEIR SVC CLBING THROUGH 13000 FT. THE FLT WAS CLR OF ALL CLOUDS AND WAS QUITE SMOOTH DURING THE ENTIRE CLB FROM 13000 FT TO THE ALT OF THE ENCOUNTER. THE SEATBELT SIGN DID IN FACT REMAIN ON FOR THE ENTIRE FLT UP TO THE INCIDENT AND THE SUBSEQUENT RETURN TO HEATHROW. THERE WERE ABSOLUTELY NO INDICATIONS OF ANY TURB IN OUR AREA OF OPS. SEVERAL FLT ATTENDANTS WERE INJURED DURING THIS ENCOUNTER. WE RETURNED TO LONDON AFTER IT WAS OBVIOUS TO US THE NATURE AND SEVERITY OF THEIR INJURIES.

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.