Narrative:

Approximately 2 hours into flight on airway routes; first indication of a problem was the fwd lav smoke alarm going off. Flight attendants immediately called cockpit to inform us that the cabin was filling up with smoke. Declared an emergency. Both the FMC and ATC confirmed the closest airport to be ZZZ; with another option ZZZ1; both at 197 miles away. The flight attendants ran their checklists and stayed in communication as they attempted to locate the source of the smoke. We ran our checklists and could not determine the source of the smoke. On the approach to ZZZ; a deadheading mechanic called the cockpit on the intercom and suggested that he thought that the smoke smelled like a burning pack. At almost the same time we had a very brief ECAM bleed page flashing advisory; but all indications appeared normal. We elected to turn off the #2 pack as it was running hotter than #1 but well within normal limits. On final approach; when discussing the need to possibly evacuate with the purser; she informed us that the smoke was dissipating. Overweight landing was smooth; no evacuation initiated and normal taxi in the gate.

Google
 

Original NASA ASRS Text

Title: AN A300-600R FLT CREW HAS SMOKE/FUMES IN CABIN; DECLARES EMER AND DIVERTS.

Narrative: APPROX 2 HRS INTO FLT ON AIRWAY ROUTES; FIRST INDICATION OF A PROB WAS THE FWD LAV SMOKE ALARM GOING OFF. FLT ATTENDANTS IMMEDIATELY CALLED COCKPIT TO INFORM US THAT THE CABIN WAS FILLING UP WITH SMOKE. DECLARED AN EMER. BOTH THE FMC AND ATC CONFIRMED THE CLOSEST ARPT TO BE ZZZ; WITH ANOTHER OPTION ZZZ1; BOTH AT 197 MILES AWAY. THE FLT ATTENDANTS RAN THEIR CHKLISTS AND STAYED IN COM AS THEY ATTEMPTED TO LOCATE THE SOURCE OF THE SMOKE. WE RAN OUR CHKLISTS AND COULD NOT DETERMINE THE SOURCE OF THE SMOKE. ON THE APCH TO ZZZ; A DEADHEADING MECHANIC CALLED THE COCKPIT ON THE INTERCOM AND SUGGESTED THAT HE THOUGHT THAT THE SMOKE SMELLED LIKE A BURNING PACK. AT ALMOST THE SAME TIME WE HAD A VERY BRIEF ECAM BLEED PAGE FLASHING ADVISORY; BUT ALL INDICATIONS APPEARED NORMAL. WE ELECTED TO TURN OFF THE #2 PACK AS IT WAS RUNNING HOTTER THAN #1 BUT WELL WITHIN NORMAL LIMITS. ON FINAL APCH; WHEN DISCUSSING THE NEED TO POSSIBLY EVACUATE WITH THE PURSER; SHE INFORMED US THAT THE SMOKE WAS DISSIPATING. OVERWEIGHT LNDG WAS SMOOTH; NO EVACUATION INITIATED AND NORMAL TAXI IN THE GATE.

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.