Narrative:

While I was on the third crew rest break; a burning rubber smell in the vicinity of row 30 was reported to me. I walked back to investigate the situation. I detected the odor but saw no visible smoke. I discussed the situation with the flight attendants and asked them to conduct a search of the area; including feeling the floor area for heat. No source of the odor was found. As I walked back through the area of row 30 en route to the cockpit; the smell had intensified. I returned to the flight deck and resumed the duties of pilot monitoring. We declared an emergency and proceeded to ZZZ; the closest suitable airport for landing. We ran the smoke and fumes electrical checklist; shut off left and right recirculation fans and left and right utility bus switches. At that point; the fumes diminished. It was determined that an evacuate/evacuation would not be necessary and that we would taxi to the ramp after landing. The dispatcher was notified via ACARS. A flight attendant was seated in row 30 for landing to monitor the situation. We maintained communication with the lead flight attendant who reported that situation in the cabin was normal. We made a PA to the passenger to apprise them of the situation. We completed the appropriate checklists and landed uneventfully at ZZZ. We taxied to the ramp and were met by fire trucks. No smoke was reported. The cargo area was inspected and no smoke or hot spots were detected. After about 1 hour delay due to customs concerns and ramp closure due to a thunderstorm; passenger were deplaned. No injuries or passenger problems were reported.

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Original NASA ASRS Text

Title: A B767-300 PLT RPTS DECLARING AN EMER AND DIVERTED TO A NEARBY ARPT BECAUSE OF A BURNING RUBBER SMELL. NO FIRE WAS FOUND.

Narrative: WHILE I WAS ON THE THIRD CREW REST BREAK; A BURNING RUBBER SMELL IN THE VICINITY OF ROW 30 WAS RPTED TO ME. I WALKED BACK TO INVESTIGATE THE SITUATION. I DETECTED THE ODOR BUT SAW NO VISIBLE SMOKE. I DISCUSSED THE SITUATION WITH THE FLT ATTENDANTS AND ASKED THEM TO CONDUCT A SEARCH OF THE AREA; INCLUDING FEELING THE FLOOR AREA FOR HEAT. NO SOURCE OF THE ODOR WAS FOUND. AS I WALKED BACK THROUGH THE AREA OF ROW 30 ENRTE TO THE COCKPIT; THE SMELL HAD INTENSIFIED. I RETURNED TO THE FLT DECK AND RESUMED THE DUTIES OF PLT MONITORING. WE DECLARED AN EMER AND PROCEEDED TO ZZZ; THE CLOSEST SUITABLE ARPT FOR LNDG. WE RAN THE SMOKE AND FUMES ELECTRICAL CHKLIST; SHUT OFF L AND R RECIRCULATION FANS AND L AND R UTILITY BUS SWITCHES. AT THAT POINT; THE FUMES DIMINISHED. IT WAS DETERMINED THAT AN EVAC WOULD NOT BE NECESSARY AND THAT WE WOULD TAXI TO THE RAMP AFTER LNDG. THE DISPATCHER WAS NOTIFIED VIA ACARS. A FLT ATTENDANT WAS SEATED IN ROW 30 FOR LNDG TO MONITOR THE SITUATION. WE MAINTAINED COM WITH THE LEAD FLT ATTENDANT WHO RPTED THAT SITUATION IN THE CABIN WAS NORMAL. WE MADE A PA TO THE PAX TO APPRISE THEM OF THE SITUATION. WE COMPLETED THE APPROPRIATE CHKLISTS AND LANDED UNEVENTFULLY AT ZZZ. WE TAXIED TO THE RAMP AND WERE MET BY FIRE TRUCKS. NO SMOKE WAS RPTED. THE CARGO AREA WAS INSPECTED AND NO SMOKE OR HOT SPOTS WERE DETECTED. AFTER ABOUT 1 HR DELAY DUE TO CUSTOMS CONCERNS AND RAMP CLOSURE DUE TO A TSTM; PAX WERE DEPLANED. NO INJURIES OR PAX PROBS WERE RPTED.

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.