Narrative:

About 1 1/2 hours from ireland coast, flight attendant called and said I think we have a fire back here. I sent so back to investigate. He found that an oxygen generator had discharged. Discharge had caused a strong plastic odor in cabin. The generator was in DC10-40 between seats under seat cushion. The oxygen panel door had not been opened. So I don't know how oxygen was discharged. Called maintenance a few days after incident and they said lanyard was burned off and had to be replaced. Sounds to me like lanyard was still attached so how did oxygen generator discharge? How did the oxygen generator on air carrier X discharge? Callback conversation with reporter revealed the following information: as of this date the reporter captain has had no definitive information regarding the unknown oxygen generator discharge. They were landing in amsterdam and an air safety report was filed there, but had not been promptly forwarded to reporter's company. Reporter then contacted his company by phone when returning from the flight and, as yet, they did not know the cause. Apparently the oxygen generator was deferred in amsterdam, the aircraft flew to london where a mechanic pulled the generator and installed a new one. Reporter captain, in addition to sending a company safety report, contacted alpa and they are looking into the incident as well. When the flight attendant called the cockpit because of suspected fire, the so went back to the cabin to investigate and basically followed his nose to the strong odor. He located the discharged oxygen generator in the middle seats of a row. Normally the oxygen generators on the DC10 are in the seat backs or overhead, but these seats, being at the bulkhead, had the oxygen generators under and between the seats. Reporter says that the passenger seated in that area disclaimed any knowledge of causing the discharge. The oxygen panel was not open, but feedback on the generator noted that the lanyard was burned off. Perhaps the lanyard had not been burned off, but inadvertently pulled off by a passenger, who then would not necessarily know what had occurred. Reporter captain says he will notify ASRS if the actual cause is determined.

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Original NASA ASRS Text

Title: OXYGEN GENERATOR WAS DISCHARGED DUE TO UNKNOWN CAUSES. CREATED SMOKE AND STRONG PLASTIC SMELL IN CABIN. THE OXYGEN DOOR WAS NOT OPENED AND PAX CLAIM NO KNOWLEDGE OF WHY IT DISCHARGED.

Narrative: ABOUT 1 1/2 HRS FROM IRELAND COAST, FLT ATTENDANT CALLED AND SAID I THINK WE HAVE A FIRE BACK HERE. I SENT SO BACK TO INVESTIGATE. HE FOUND THAT AN OXYGEN GENERATOR HAD DISCHARGED. DISCHARGE HAD CAUSED A STRONG PLASTIC ODOR IN CABIN. THE GENERATOR WAS IN DC10-40 BTWN SEATS UNDER SEAT CUSHION. THE OXYGEN PANEL DOOR HAD NOT BEEN OPENED. SO I DON'T KNOW HOW OXYGEN WAS DISCHARGED. CALLED MAINT A FEW DAYS AFTER INCIDENT AND THEY SAID LANYARD WAS BURNED OFF AND HAD TO BE REPLACED. SOUNDS TO ME LIKE LANYARD WAS STILL ATTACHED SO HOW DID OXYGEN GENERATOR DISCHARGE? HOW DID THE OXYGEN GENERATOR ON ACR X DISCHARGE? CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: AS OF THIS DATE THE RPTR CAPT HAS HAD NO DEFINITIVE INFO REGARDING THE UNKNOWN OXYGEN GENERATOR DISCHARGE. THEY WERE LNDG IN AMSTERDAM AND AN AIR SAFETY RPT WAS FILED THERE, BUT HAD NOT BEEN PROMPTLY FORWARDED TO RPTR'S COMPANY. RPTR THEN CONTACTED HIS COMPANY BY PHONE WHEN RETURNING FROM THE FLT AND, AS YET, THEY DID NOT KNOW THE CAUSE. APPARENTLY THE OXYGEN GENERATOR WAS DEFERRED IN AMSTERDAM, THE ACFT FLEW TO LONDON WHERE A MECH PULLED THE GENERATOR AND INSTALLED A NEW ONE. RPTR CAPT, IN ADDITION TO SENDING A COMPANY SAFETY RPT, CONTACTED ALPA AND THEY ARE LOOKING INTO THE INCIDENT AS WELL. WHEN THE FLT ATTENDANT CALLED THE COCKPIT BECAUSE OF SUSPECTED FIRE, THE SO WENT BACK TO THE CABIN TO INVESTIGATE AND BASICALLY FOLLOWED HIS NOSE TO THE STRONG ODOR. HE LOCATED THE DISCHARGED OXYGEN GENERATOR IN THE MIDDLE SEATS OF A ROW. NORMALLY THE OXYGEN GENERATORS ON THE DC10 ARE IN THE SEAT BACKS OR OVERHEAD, BUT THESE SEATS, BEING AT THE BULKHEAD, HAD THE OXYGEN GENERATORS UNDER AND BTWN THE SEATS. RPTR SAYS THAT THE PAX SEATED IN THAT AREA DISCLAIMED ANY KNOWLEDGE OF CAUSING THE DISCHARGE. THE OXYGEN PANEL WAS NOT OPEN, BUT FEEDBACK ON THE GENERATOR NOTED THAT THE LANYARD WAS BURNED OFF. PERHAPS THE LANYARD HAD NOT BEEN BURNED OFF, BUT INADVERTENTLY PULLED OFF BY A PAX, WHO THEN WOULD NOT NECESSARILY KNOW WHAT HAD OCCURRED. RPTR CAPT SAYS HE WILL NOTIFY ASRS IF THE ACTUAL CAUSE IS DETERMINED.

Data retrieved from NASA's ASRS site as of July 2007 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.