Narrative:

Emergency declared for smoke in cabin. Approximately 2 hours into flight; flight attendants reported smoke in the cabin accompanied by strange smell described as 'electrical.' I was on break as relief pilot. Captain and first officer accomplished all necessary procedures and declared an emergency with ATC. Since I was already in the cabin; the captain asked me to walk through the area of concern and noted no lingering smell and no evident smoke which I reported to the captain via cabin interphone. I then returned to the cockpit and we landed in ZZZ with no incident. Maintenance found aft chiller compressor motor to be faulty. Supplemental information from acn 797267: at cruise we got a call from a flight attendant in the aft portion of aircraft and advised us of electrical smell/odor and visible smoke in the area of the left aft lavatory. We completed our immediate action items from QRH; squawked 7700; declared an emergency; started direct to ZZZ. Was cleared to descend. I had a couple flight attendants walk through the cabin with no shoes to check the floor for hot spots. There were none. Within a short period of time; it appeared the QRH items had the problem isolated. Smoke dissipated. We requested emergency equipment meet us. As we cleared the runway; we requested a scan of the aircraft for any hot spots. Got the ok from them and taxied to the gate. We requested fans for the brakes and chocks. Crash fire rescue equipment followed the aircraft to the gate. Passenger deplaned; no further problems.

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Original NASA ASRS Text

Title: B767 FLT CREW IS INFORMED OF SMOKE IN CABIN BY FLT ATTENDANT. EMERGENCY DECLARED; QRH COMPLIED WITH; AND FLIGHT DIVERTED TO NEAREST SUITABLE ARPT.

Narrative: EMER DECLARED FOR SMOKE IN CABIN. APPROX 2 HRS INTO FLT; FLT ATTENDANTS RPTED SMOKE IN THE CABIN ACCOMPANIED BY STRANGE SMELL DESCRIBED AS 'ELECTRICAL.' I WAS ON BREAK AS RELIEF PLT. CAPT AND FO ACCOMPLISHED ALL NECESSARY PROCS AND DECLARED AN EMER WITH ATC. SINCE I WAS ALREADY IN THE CABIN; THE CAPT ASKED ME TO WALK THROUGH THE AREA OF CONCERN AND NOTED NO LINGERING SMELL AND NO EVIDENT SMOKE WHICH I RPTED TO THE CAPT VIA CABIN INTERPHONE. I THEN RETURNED TO THE COCKPIT AND WE LANDED IN ZZZ WITH NO INCIDENT. MAINT FOUND AFT CHILLER COMPRESSOR MOTOR TO BE FAULTY. SUPPLEMENTAL INFO FROM ACN 797267: AT CRUISE WE GOT A CALL FROM A FLT ATTENDANT IN THE AFT PORTION OF ACFT AND ADVISED US OF ELECTRICAL SMELL/ODOR AND VISIBLE SMOKE IN THE AREA OF THE L AFT LAVATORY. WE COMPLETED OUR IMMEDIATE ACTION ITEMS FROM QRH; SQUAWKED 7700; DECLARED AN EMER; STARTED DIRECT TO ZZZ. WAS CLRED TO DSND. I HAD A COUPLE FLT ATTENDANTS WALK THROUGH THE CABIN WITH NO SHOES TO CHK THE FLOOR FOR HOT SPOTS. THERE WERE NONE. WITHIN A SHORT PERIOD OF TIME; IT APPEARED THE QRH ITEMS HAD THE PROB ISOLATED. SMOKE DISSIPATED. WE REQUESTED EMER EQUIP MEET US. AS WE CLRED THE RWY; WE REQUESTED A SCAN OF THE ACFT FOR ANY HOT SPOTS. GOT THE OK FROM THEM AND TAXIED TO THE GATE. WE REQUESTED FANS FOR THE BRAKES AND CHOCKS. CFR FOLLOWED THE ACFT TO THE GATE. PAX DEPLANED; NO FURTHER PROBS.

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.