Narrative:

While cruising at FL350 on a flight from phl to atl the 'a' or lead flight attendant came to the cockpit to report a burning plastic smell in the first class cabin. I had him check the lavatories and the galley, then pull the circuit breaker for the oven and galleys. The smell continued, so I informed ATC and we diverted to roa. The first officer and I donned smoke goggles and oxygen masks and executed the QRH procedures and all applicable checklists. I had ATC call out the equipment, just in case. The only mistake I think we made was that I did not say or declare an emergency, when in fact, I meant to do so. ATC handling was superb and we were on the ground in mins. I stopped on the taxiway and shut down the engines. The firefighters determined there was no immediate problem. No evacuate/evacuation occurred. I then taxied to the gate and off loaded the people. Our mechanics later determined it was caused by a malfunctioning emergency battery pack that overheated next to some fiberglas or plastic, causing the smell.

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Original NASA ASRS Text

Title: A B737-300 IN CRUISE AT FL350 DIVERTS, DUE TO A BURNING PLASTIC ODOR CAUSED BY AN OVERHEATED EMER EXIT BATTERY PACK.

Narrative: WHILE CRUISING AT FL350 ON A FLT FROM PHL TO ATL THE 'A' OR LEAD FLT ATTENDANT CAME TO THE COCKPIT TO RPT A BURNING PLASTIC SMELL IN THE FIRST CLASS CABIN. I HAD HIM CHK THE LAVATORIES AND THE GALLEY, THEN PULL THE CIRCUIT BREAKER FOR THE OVEN AND GALLEYS. THE SMELL CONTINUED, SO I INFORMED ATC AND WE DIVERTED TO ROA. THE FO AND I DONNED SMOKE GOGGLES AND OXYGEN MASKS AND EXECUTED THE QRH PROCS AND ALL APPLICABLE CHKLISTS. I HAD ATC CALL OUT THE EQUIP, JUST IN CASE. THE ONLY MISTAKE I THINK WE MADE WAS THAT I DID NOT SAY OR DECLARE AN EMER, WHEN IN FACT, I MEANT TO DO SO. ATC HANDLING WAS SUPERB AND WE WERE ON THE GND IN MINS. I STOPPED ON THE TXWY AND SHUT DOWN THE ENGS. THE FIREFIGHTERS DETERMINED THERE WAS NO IMMEDIATE PROB. NO EVAC OCCURRED. I THEN TAXIED TO THE GATE AND OFF LOADED THE PEOPLE. OUR MECHS LATER DETERMINED IT WAS CAUSED BY A MALFUNCTIONING EMER BATTERY PACK THAT OVERHEATED NEXT TO SOME FIBERGLAS OR PLASTIC, CAUSING THE SMELL.

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.