Narrative:

Otherwise normal flight. Smooth atmosphere; clear sky. Co-pilot is flying pilot. [There was a] strong odor. Shortly thereafter; 'left recirc fan' message appeared on EICAS. [We] manually turned off illuminated fan switch; scanned cockpit with flashlight for related or other problems. None found. Odor was determined to smell like overheating electronic components. The odor caused no irritation of the eyes or mucous membranes nor did it cause difficulty in breathing. There was no smoke and there was no reduction in visibility in the cabin or the cockpit at this time. We had not yet reached our mid flight etp. Asked cabin crew if they also noticed the odor and they did. Per procedures; advised cabin crew to turn off ife and pc power switches. Captain; pilot not flying; called 'pan pan pan' on HF; bad reception ATC advised for us to try VHF; successful. Odor significantly dissipated by now. ACARS'd dispatch and maintenance of our warnings and situation. Maintenance advised us to pull 'left recirc fan' circuit breaker overhead. [I] awoke resting co-pilot on break. Satcom to ATC failed. Contacted dispatch; dispatch concurred divert. Dispatch advised the diversion airport weather 15 miles visibility; cavok. Advised dispatch that the landing ETA is XA20. Resting copilot returns to pilot flying duties in first officer's seat replacing relief first officer. Dispatch - how to return disabled electric seats to upright position? Should we re-power utility buses to accomplish this for landing? Maintenance advised that they saw no problem with this idea. Dispatch asked what was the 'mood of the crew' at this time. Captain replied that the mood was fine. Dispatch told us that the airport was ready and waiting for our arrival but they did not have the capability to inspect a company plane to allow ETOPS pre departure clearance; so we would be routed via 60-minute ETOPS for the return flight to our scheduled destination. They expected a 60-minute turn time on the ground at the diversion airport. Call to cabin. Asks how everyone is; they are all fine; passengers are fine. Captain briefs passengers again; advised that we could move all business class passengers to existing open coach seats for landing. Reviewed and briefed airport approach and back course approach to straight-in for the runway. First officer reviewed fom to review compliance; radar contact with airport. Captain briefs passengers again. [We] contacted airport rescue and fire fighters. 'Emergency aircraft' was cleared for the back course approach to the runway; airport rescue and fire fighters were standing by; and we were cleared to stop on runway after landing for inspection. [We] landed; airport rescue and fire fighters' [performed] exterior inspection of stopped aircraft on runway. Released from inspection; followed guide vehicle to hard stand; chocked. Mechanic asked us to close the left recirc fan switch and circuit breaker so he could watch the fan. As we did; the smell immediately returned to the cabin and the cockpit. The mechanic returned and said that while it was off; the fan did not appear to have burned or caught fire; but once it was re-energized he noticed as we did that the smell returned and that the fan motor was loose on its bearings. He said that he did not observe any smoke or fire during his test.

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Original NASA ASRS Text

Title: A B767-400's cabin recirculation fan failed at cruise causing flight deck and cabin smoke and fumes. The crew declared an emergency; complied with the QRH and diverted to an enroute airport

Narrative: Otherwise normal flight. Smooth atmosphere; clear sky. Co-pilot is flying pilot. [There was a] strong odor. Shortly thereafter; 'L RECIRC FAN' message appeared on EICAS. [We] manually turned off illuminated fan switch; scanned cockpit with flashlight for related or other problems. None found. Odor was determined to smell like overheating electronic components. The odor caused no irritation of the eyes or mucous membranes nor did it cause difficulty in breathing. There was no smoke and there was no reduction in visibility in the cabin or the cockpit at this time. We had not yet reached our mid flight ETP. Asked cabin crew if they also noticed the odor and they did. Per procedures; advised cabin crew to turn off IFE and PC power switches. Captain; pilot not flying; called 'PAN PAN PAN' on HF; bad reception ATC advised for us to try VHF; successful. Odor significantly dissipated by now. ACARS'd Dispatch and Maintenance of our warnings and situation. Maintenance advised us to pull 'L RECIRC FAN' circuit breaker overhead. [I] awoke resting co-pilot on break. SATCOM to ATC failed. Contacted Dispatch; Dispatch concurred divert. Dispatch advised the diversion airport weather 15 miles visibility; CAVOK. Advised Dispatch that the landing ETA is XA20. Resting copilot returns to pilot flying duties in First Officer's seat replacing relief First Officer. Dispatch - how to return disabled electric seats to upright position? Should we re-power utility buses to accomplish this for landing? Maintenance advised that they saw no problem with this idea. Dispatch asked what was the 'mood of the crew' at this time. Captain replied that the mood was fine. Dispatch told us that the airport was ready and waiting for our arrival but they did not have the capability to inspect a company plane to allow ETOPS PDC; so we would be routed via 60-minute ETOPS for the return flight to our scheduled destination. They expected a 60-minute turn time on the ground at the diversion airport. Call to cabin. Asks how everyone is; they are all fine; passengers are fine. Captain briefs passengers again; advised that we could move all business class passengers to existing open coach seats for landing. Reviewed and briefed Airport Approach and Back Course Approach to straight-in for the runway. First Officer reviewed FOM to review compliance; radar contact with Airport. Captain briefs passengers again. [We] contacted Airport Rescue and Fire Fighters. 'Emergency Aircraft' was cleared for the Back Course Approach to the runway; Airport Rescue and Fire Fighters were standing by; and we were cleared to stop on runway after landing for inspection. [We] landed; Airport Rescue and Fire Fighters' [performed] exterior inspection of stopped aircraft on runway. Released from inspection; followed guide vehicle to hard stand; chocked. Mechanic asked us to close the L RECIRC FAN switch and circuit breaker so he could watch the fan. As we did; the smell immediately returned to the cabin and the cockpit. The mechanic returned and said that while it was off; the fan did not appear to have burned or caught fire; but once it was re-energized he noticed as we did that the smell returned and that the fan motor was loose on its bearings. He said that he did not observe any smoke or fire during his test.

Data retrieved from NASA's ASRS site as of April 2012 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.