B777 encountered wake turbulence at cruise altitude.

Attributes
ACN	769622
Time
Date	200801
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzzz.airport
State Reference	FO
Altitude	msl single value : 33000
Environment
Flight Conditions	IMC
Aircraft 1
Controlling Facilities	artcc : zzzz.artcc artcc : zzz.artcc
Operator	common carrier : air carrier
Make Model Name	B777-200
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer observation : company check pilot
Experience	flight time last 90 days : 80 flight time total : 20000 flight time type : 3200
ASRS Report	769622
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 150 flight time total : 18000 flight time type : 10
ASRS Report	769955
Events
Anomaly	inflight encounter : wake turbulence
Independent Detector	other flight crewa
Supplementary
Problem Areas	Environmental Factor
Primary Problem	Environmental Factor

Narrative:

Right after leveling at FL330 cruise and on a vector from control we hit the wake of another aircraft. Most of the aircraft in our area were to our left or right. No TCAS aircraft on our track. We had a moderate turbulence event associated with most likely aircraft wake lasting several seconds. Conditions at the time were IMC; light chop with the seatbelt sign on. The flight attendants had started their service and carts were coming out of the galleys. First report from the cabin was that no one was injured. Later a flight attendant reported having lower back pain. She was maneuvering a beverage cart at the time of the event and may have strained her back. She took a pain reliever and continued her in-flight duties.

Original NASA ASRS Text

Title: B777 ENCOUNTERED WAKE TURB AT CRUISE ALT.

Narrative: RIGHT AFTER LEVELING AT FL330 CRUISE AND ON A VECTOR FROM CONTROL WE HIT THE WAKE OF ANOTHER AIRCRAFT. MOST OF THE AIRCRAFT IN OUR AREA WERE TO OUR LEFT OR RIGHT. NO TCAS ACFT ON OUR TRACK. WE HAD A MODERATE TURBULENCE EVENT ASSOCIATED WITH MOST LIKELY ACFT WAKE LASTING SEVERAL SECONDS. CONDITIONS AT THE TIME WERE IMC; LIGHT CHOP WITH THE SEATBELT SIGN ON. THE FLT ATTENDANTS HAD STARTED THEIR SERVICE AND CARTS WERE COMING OUT OF THE GALLEYS. FIRST REPORT FROM THE CABIN WAS THAT NO ONE WAS INJURED. LATER A FLT ATTENDANT REPORTED HAVING LOWER BACK PAIN. SHE WAS MANEUVERING A BEVERAGE CART AT THE TIME OF THE EVENT AND MAY HAVE STRAINED HER BACK. SHE TOOK A PAIN RELIEVER AND CONTINUED HER IN-FLIGHT DUTIES.

Data retrieved from NASA's ASRS site as of May 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.