Narrative:

While on second break; I was woken from break and advised by captain that we were approximately 30 mins from going 'feet wet;' and he asked me to investigate possible electrical smells in location of last few rows of economy and aft galley. Ovens and master switch had been turned off (aft galley); as well as recirculation fans. Upon approaching last 4 rows of economy; I smelled a strong odor which got stronger; as I entered aft galley near door 4L. I listened to flight attendant's concerns (approximately 5-6 present) about the strong smell. Investigated the ovens and lavatories for possible source. No smoke or fire noticed. Unable to determine and/or locate source of odor. Not an electrical smell; but more of a 'hot metal' smell. No video/entertainment issues. No lights flickering. Returned to cockpit so that other first officer could give a second opinion. At first he didn't smell anything; but as he was about to leave the galley; he and 5 other flight attendants got a whiff of a concentrated strong smell. He agreed with the description of 'hot metal' smell and his concern increased. Meanwhile; captain had been communicating with dispatch and maintenance via satcom about the situation. Based on our concerns about continuing flight over the atlantic with possible deterioration and/or increase in 'hot metal' smell; and knowing that this aircraft had had numerous electrical issues and flight cancellations the past 2 days; we decided it was the prudent and safest course to discontinue overwater flight and divert to foreign or united states airport. The captain coordination with dispatch for diversion station best able to handle maintenance and passenger. During attempt to get ATC re-clearance for diversion; it became difficult to raise oceanic radio. Approximately XA00Z (east of xxxxx intersection); course change direct to ZZZ1 initiated. Descended from FL350 to FL345. Squawked 7700. Once established on direct routing and pan; pan; pan; communications made with oceanic radio. Emergency declared and received clearance to yyyyy intersection (ETA XA20Z). Dispatch then advised us that ZZZ1 would be best united states destination. ATC clearance received XC20. In the event the situation had deteriorated; ZZZ2 and ZZZ1 were options. As flight progressed; smell dissipated until final approach into ZZZ2 when the flight attendants noted that the 'smell' returned and seemed strongest coming from the air vents. Mechanics debriefed at ZZZ2 gate. Callback conversation with reporter revealed the following information: reporter stated that air carrier maintenance removed panels; circuit breaker panel; lav motors and could find nothing wrong with the aircraft. The crew flew that same aircraft later that day and had no anomalies with it.

Related reports:

Google
 

Original NASA ASRS Text

Title: A B777 CREW DECLARED AN EMER AND DIVERTED FOLLOWING A STRONG HOT METAL SMELL IN THE AFT GALLEY NEAR DOOR 4L.

Narrative: WHILE ON SECOND BREAK; I WAS WOKEN FROM BREAK AND ADVISED BY CAPT THAT WE WERE APPROX 30 MINS FROM GOING 'FEET WET;' AND HE ASKED ME TO INVESTIGATE POSSIBLE ELECTRICAL SMELLS IN LOCATION OF LAST FEW ROWS OF ECONOMY AND AFT GALLEY. OVENS AND MASTER SWITCH HAD BEEN TURNED OFF (AFT GALLEY); AS WELL AS RECIRCULATION FANS. UPON APCHING LAST 4 ROWS OF ECONOMY; I SMELLED A STRONG ODOR WHICH GOT STRONGER; AS I ENTERED AFT GALLEY NEAR DOOR 4L. I LISTENED TO FLT ATTENDANT'S CONCERNS (APPROX 5-6 PRESENT) ABOUT THE STRONG SMELL. INVESTIGATED THE OVENS AND LAVATORIES FOR POSSIBLE SOURCE. NO SMOKE OR FIRE NOTICED. UNABLE TO DETERMINE AND/OR LOCATE SOURCE OF ODOR. NOT AN ELECTRICAL SMELL; BUT MORE OF A 'HOT METAL' SMELL. NO VIDEO/ENTERTAINMENT ISSUES. NO LIGHTS FLICKERING. RETURNED TO COCKPIT SO THAT OTHER FO COULD GIVE A SECOND OPINION. AT FIRST HE DIDN'T SMELL ANYTHING; BUT AS HE WAS ABOUT TO LEAVE THE GALLEY; HE AND 5 OTHER FLT ATTENDANTS GOT A WHIFF OF A CONCENTRATED STRONG SMELL. HE AGREED WITH THE DESCRIPTION OF 'HOT METAL' SMELL AND HIS CONCERN INCREASED. MEANWHILE; CAPT HAD BEEN COMMUNICATING WITH DISPATCH AND MAINT VIA SATCOM ABOUT THE SITUATION. BASED ON OUR CONCERNS ABOUT CONTINUING FLT OVER THE ATLANTIC WITH POSSIBLE DETERIORATION AND/OR INCREASE IN 'HOT METAL' SMELL; AND KNOWING THAT THIS ACFT HAD HAD NUMEROUS ELECTRICAL ISSUES AND FLT CANCELLATIONS THE PAST 2 DAYS; WE DECIDED IT WAS THE PRUDENT AND SAFEST COURSE TO DISCONTINUE OVERWATER FLT AND DIVERT TO FOREIGN OR UNITED STATES ARPT. THE CAPT COORD WITH DISPATCH FOR DIVERSION STATION BEST ABLE TO HANDLE MAINT AND PAX. DURING ATTEMPT TO GET ATC RE-CLRNC FOR DIVERSION; IT BECAME DIFFICULT TO RAISE OCEANIC RADIO. APPROX XA00Z (E OF XXXXX INTXN); COURSE CHANGE DIRECT TO ZZZ1 INITIATED. DSNDED FROM FL350 TO FL345. SQUAWKED 7700. ONCE ESTABLISHED ON DIRECT ROUTING AND PAN; PAN; PAN; COMS MADE WITH OCEANIC RADIO. EMER DECLARED AND RECEIVED CLRNC TO YYYYY INTXN (ETA XA20Z). DISPATCH THEN ADVISED US THAT ZZZ1 WOULD BE BEST UNITED STATES DEST. ATC CLRNC RECEIVED XC20. IN THE EVENT THE SITUATION HAD DETERIORATED; ZZZ2 AND ZZZ1 WERE OPTIONS. AS FLT PROGRESSED; SMELL DISSIPATED UNTIL FINAL APCH INTO ZZZ2 WHEN THE FLT ATTENDANTS NOTED THAT THE 'SMELL' RETURNED AND SEEMED STRONGEST COMING FROM THE AIR VENTS. MECHS DEBRIEFED AT ZZZ2 GATE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED THAT ACR MAINT REMOVED PANELS; CIRCUIT BREAKER PANEL; LAV MOTORS AND COULD FIND NOTHING WRONG WITH THE ACFT. THE CREW FLEW THAT SAME ACFT LATER THAT DAY AND HAD NO ANOMALIES WITH IT.

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.