Narrative:

I was the PF (left seat) during a severe turbulence encounter. The event occurred on aug/mon/06 approximately 27 NM north of ankar intersection at FL330. Both pilots had WX radar displayed: midrange manual tilt (approximately 1-2 units nose down) with 80 NM range for the PF and 40 NM range for the PNF. There were stars visible; however; no moon and no discernable horizon. The seatbelt sign was off/automatic since the ride was smooth. Without notice the aircraft encountered violent turbulence pushing both pilots against lap belts (0 G) and impacting loud hail on the wind screen. The autoplt remained engaged and no overspd was observed; however; the vsi fluctuated approximately '+' or '-' 1500-1800 FPM and angle of bank '+' or '-' 15 degrees. Fortunately no passenger or flight attendants were standing at the time; however; 2 flight attendants in the aft galley did become airborne -- one landed in the jumpseat (resulting in back pain); the other on the floor (no injury). They also reported a galley cart being launched approximately 1 ft in the air. All galley items on the counter were knocked over or thrown to the floor. No other crew injuries were noted. The entire event lasted less than 10 seconds. Both ATC and dispatch were notified. The rest of the flight was uneventful. Station maintenance was also debriefed upon arrival. Supplemental information from acn 707330: dark night; no moon; radar on. 1 pilot 80 mi scale; other pilot 40 mi scale. No signs of convective activity. Relief pilot just finished his break and I was relieved to go on break. About 15 mins into break I was laying down and I felt what appeared to be a 5-10 second jolt -- much like hitting a thunderstorm shaft that is difficult to paint and will only show up on smaller scales and 20-40 mi ahead. It appeared to me to be a moderate jolt with an up then down force. Several call buttons went off but things were quiet after 2 or 3 mins. I assumed no significant problems and continued my rest. After 2 hours 30 mins; I returned to the cockpit to discover the first officer's had reported severe turbulence to dispatch and maintenance. Their experience was a +/-1000 ft vsi deviation; with no autoplt disconnect and a report from the aft galley a cart had been bounced around. No passenger or crew concerns were reported at that time. On termination of the flight; I reviewed the incident with the purser and was told 2 flight attendants received muscle strains from the incident. I did ask the 2 flight attendants if they required medical attention and was told no. I also asked again on the next day and the flight attendants were ok. I also reviewed the incident with the mechanic and told him I thought it was nothing more than moderate turbulence and was not in the cockpit when the first officer's made the report of severe turbulence. I further reviewed with the first officer's the significance between severe and moderate turbulence and discussed that with severe turbulence; articles are tossed about the airplane and they agreed that was not the case. I also discussed reports which require notification of the captain and operational reports.

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Original NASA ASRS Text

Title: A B767-300 ENCOUNTERED MODERATE TO SEVERE TURB IN CRUISE FLT; SLIGHTLY INJURING 2 FLT ATTENDANTS.

Narrative: I WAS THE PF (L SEAT) DURING A SEVERE TURB ENCOUNTER. THE EVENT OCCURRED ON AUG/MON/06 APPROX 27 NM N OF ANKAR INTXN AT FL330. BOTH PLTS HAD WX RADAR DISPLAYED: MIDRANGE MANUAL TILT (APPROX 1-2 UNITS NOSE DOWN) WITH 80 NM RANGE FOR THE PF AND 40 NM RANGE FOR THE PNF. THERE WERE STARS VISIBLE; HOWEVER; NO MOON AND NO DISCERNABLE HORIZON. THE SEATBELT SIGN WAS OFF/AUTO SINCE THE RIDE WAS SMOOTH. WITHOUT NOTICE THE ACFT ENCOUNTERED VIOLENT TURB PUSHING BOTH PLTS AGAINST LAP BELTS (0 G) AND IMPACTING LOUD HAIL ON THE WIND SCREEN. THE AUTOPLT REMAINED ENGAGED AND NO OVERSPD WAS OBSERVED; HOWEVER; THE VSI FLUCTUATED APPROX '+' OR '-' 1500-1800 FPM AND ANGLE OF BANK '+' OR '-' 15 DEGS. FORTUNATELY NO PAX OR FLT ATTENDANTS WERE STANDING AT THE TIME; HOWEVER; 2 FLT ATTENDANTS IN THE AFT GALLEY DID BECOME AIRBORNE -- ONE LANDED IN THE JUMPSEAT (RESULTING IN BACK PAIN); THE OTHER ON THE FLOOR (NO INJURY). THEY ALSO RPTED A GALLEY CART BEING LAUNCHED APPROX 1 FT IN THE AIR. ALL GALLEY ITEMS ON THE COUNTER WERE KNOCKED OVER OR THROWN TO THE FLOOR. NO OTHER CREW INJURIES WERE NOTED. THE ENTIRE EVENT LASTED LESS THAN 10 SECONDS. BOTH ATC AND DISPATCH WERE NOTIFIED. THE REST OF THE FLT WAS UNEVENTFUL. STATION MAINT WAS ALSO DEBRIEFED UPON ARR. SUPPLEMENTAL INFO FROM ACN 707330: DARK NIGHT; NO MOON; RADAR ON. 1 PLT 80 MI SCALE; OTHER PLT 40 MI SCALE. NO SIGNS OF CONVECTIVE ACTIVITY. RELIEF PLT JUST FINISHED HIS BREAK AND I WAS RELIEVED TO GO ON BREAK. ABOUT 15 MINS INTO BREAK I WAS LAYING DOWN AND I FELT WHAT APPEARED TO BE A 5-10 SECOND JOLT -- MUCH LIKE HITTING A TSTM SHAFT THAT IS DIFFICULT TO PAINT AND WILL ONLY SHOW UP ON SMALLER SCALES AND 20-40 MI AHEAD. IT APPEARED TO ME TO BE A MODERATE JOLT WITH AN UP THEN DOWN FORCE. SEVERAL CALL BUTTONS WENT OFF BUT THINGS WERE QUIET AFTER 2 OR 3 MINS. I ASSUMED NO SIGNIFICANT PROBS AND CONTINUED MY REST. AFTER 2 HRS 30 MINS; I RETURNED TO THE COCKPIT TO DISCOVER THE FO'S HAD RPTED SEVERE TURB TO DISPATCH AND MAINT. THEIR EXPERIENCE WAS A +/-1000 FT VSI DEV; WITH NO AUTOPLT DISCONNECT AND A RPT FROM THE AFT GALLEY A CART HAD BEEN BOUNCED AROUND. NO PAX OR CREW CONCERNS WERE RPTED AT THAT TIME. ON TERMINATION OF THE FLT; I REVIEWED THE INCIDENT WITH THE PURSER AND WAS TOLD 2 FLT ATTENDANTS RECEIVED MUSCLE STRAINS FROM THE INCIDENT. I DID ASK THE 2 FLT ATTENDANTS IF THEY REQUIRED MEDICAL ATTN AND WAS TOLD NO. I ALSO ASKED AGAIN ON THE NEXT DAY AND THE FLT ATTENDANTS WERE OK. I ALSO REVIEWED THE INCIDENT WITH THE MECH AND TOLD HIM I THOUGHT IT WAS NOTHING MORE THAN MODERATE TURB AND WAS NOT IN THE COCKPIT WHEN THE FO'S MADE THE RPT OF SEVERE TURB. I FURTHER REVIEWED WITH THE FO'S THE SIGNIFICANCE BTWN SEVERE AND MODERATE TURB AND DISCUSSED THAT WITH SEVERE TURB; ARTICLES ARE TOSSED ABOUT THE AIRPLANE AND THEY AGREED THAT WAS NOT THE CASE. I ALSO DISCUSSED RPTS WHICH REQUIRE NOTIFICATION OF THE CAPT AND OPERATIONAL RPTS.

Data retrieved from NASA's ASRS site as of January 2009 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.