Narrative:

While cruising at FL370; a business class flight attendant notified us a burning odor which appeared to be of an electrical origin. It appeared to be emanating from warming oven '547' and I directed all power to be removed from the galleys. The flight attendant stated that the odor was still present and I then asked first officer who had just began his break to assist with the troubleshooting. The carts were removed from the storage area below the oven and a hazy smoke with a noxious odor was pooling in that area. An emergency was declared with center and ZZZZ was my choice for the divert based upon time. We dumped fuel between FL340 and 15000 ft and the exact location was unknown due to workload including the 'smoke/fume' checklist. I can relay the fact that we were overwater during the fuel dump accomplishment. The landing weight was approximately 459000 pounds and crash fire rescue equipment was awaiting our arrival. After stopping the aircraft on the taxiway; crash fire rescue equipment thoroughly inspected the exterior visually and with thermal imaging equipment. We received a normal finding from them and had the trucks follow us to the assigned parking stand. Passenger were disembarked quickly via mobile stairs. Contract maintenance provided a very thorough inspection and determined that no damage was evident from the overheated warming oven. The remaining portion of the galley was re-pwred for 1 hour with no further symptoms after isolating power to the faulty component. There was a previous PIREP entered in the logbook reflecting a temperature related issue on this oven.

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Original NASA ASRS Text

Title: A B777 CREW IN CRUISE FLT WAS NOTIFIED BY FLT ATTENDANT OF A BURNING ODOR AND SMOKE ASSOCIATED WITH AN OVEN. THEY DECLARED AN EMER AND DIVERTED TO DUB.

Narrative: WHILE CRUISING AT FL370; A BUSINESS CLASS FLT ATTENDANT NOTIFIED US A BURNING ODOR WHICH APPEARED TO BE OF AN ELECTRICAL ORIGIN. IT APPEARED TO BE EMANATING FROM WARMING OVEN '547' AND I DIRECTED ALL PWR TO BE REMOVED FROM THE GALLEYS. THE FLT ATTENDANT STATED THAT THE ODOR WAS STILL PRESENT AND I THEN ASKED FO WHO HAD JUST BEGAN HIS BREAK TO ASSIST WITH THE TROUBLESHOOTING. THE CARTS WERE REMOVED FROM THE STORAGE AREA BELOW THE OVEN AND A HAZY SMOKE WITH A NOXIOUS ODOR WAS POOLING IN THAT AREA. AN EMER WAS DECLARED WITH CTR AND ZZZZ WAS MY CHOICE FOR THE DIVERT BASED UPON TIME. WE DUMPED FUEL BTWN FL340 AND 15000 FT AND THE EXACT LOCATION WAS UNKNOWN DUE TO WORKLOAD INCLUDING THE 'SMOKE/FUME' CHKLIST. I CAN RELAY THE FACT THAT WE WERE OVERWATER DURING THE FUEL DUMP ACCOMPLISHMENT. THE LNDG WT WAS APPROX 459000 LBS AND CFR WAS AWAITING OUR ARR. AFTER STOPPING THE ACFT ON THE TXWY; CFR THOROUGHLY INSPECTED THE EXTERIOR VISUALLY AND WITH THERMAL IMAGING EQUIP. WE RECEIVED A NORMAL FINDING FROM THEM AND HAD THE TRUCKS FOLLOW US TO THE ASSIGNED PARKING STAND. PAX WERE DISEMBARKED QUICKLY VIA MOBILE STAIRS. CONTRACT MAINT PROVIDED A VERY THOROUGH INSPECTION AND DETERMINED THAT NO DAMAGE WAS EVIDENT FROM THE OVERHEATED WARMING OVEN. THE REMAINING PORTION OF THE GALLEY WAS RE-PWRED FOR 1 HR WITH NO FURTHER SYMPTOMS AFTER ISOLATING PWR TO THE FAULTY COMPONENT. THERE WAS A PREVIOUS PIREP ENTERED IN THE LOGBOOK REFLECTING A TEMP RELATED ISSUE ON THIS OVEN.

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.