Narrative:

After we leveled at FL300; we noticed a strong smell of burning plastic; rubber or wiring. We immediately did the memory items of the fire/smoke/fumes in cockpit checklist. I informed ATC about strong fumes in the cockpit and possible smoke. The dome light was turned on and no smoke in the cockpit noticed. We decided that smoke goggles were not required yet. I called the flight attendants and asked if they observed any smoke or fumes. They informed me that they did not. I declared an emergency with center and asked for vectors for ZZZ. We completed the remainder of the QRH checklist approximately 60 NM from ZZZ. I called the flight attendants back and informed them about the situation; the divert to ZZZ; and the time it would take to reach ZZZ. They were told 10 - 15 minutes and to 'secure the cabin.' I was now informed by the a flight attendant that he could smell a faint burning smell from down low by the cockpit door; but no visible smoke in the cabin. I typed an ACARS to dispatch that read: fumes in cockpit; diverting to ZZZ. I was later told on the phone with dispatch that he never received the message. We later received an ACARS asking; 'where are you?' the last message we sent was: 30 NM south of ZZZ. I made a PA to the customers informing them about the situation; divert to ZZZ; and that we would be landing in 10 - 15 minutes. I repeated twice that emergency vehicles and personnel would inspect our aircraft after landing and for them to remain seated until further instructions from crewmembers. After landing on X; we cleared the runway at Y and stopped the aircraft for fire/rescue to inspect the exterior. In an attempt to improve communication with everyone involved; I removed my O2 mask; but the fumes/smell were still too strong and I put the mask on again for the taxi to the gate. Fire/rescue followed us to gate. After parking and completing the checklist; fire/rescue came up to the cockpit to inspect and asked if we needed any further assistance. He also noticed the smell of burned plastic or wiring. I made a PA thanking our customers for being cooperative during the event and that we were sorry for the inconvenience; but that safety is always our number one priority. No violations of FARS were required during this emergency.callback conversation with reporter revealed the following information: electrical wiring to the leading edge devices indicator lights on the overhead panel had shorted out. They did not notice if the associated circuit breaker lights had popped.

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Original NASA ASRS Text

Title: B737 CREW AT FL300 SMELLS STRONG ELECTRICAL FUMES AND DIVERTS.

Narrative: AFTER WE LEVELED AT FL300; WE NOTICED A STRONG SMELL OF BURNING PLASTIC; RUBBER OR WIRING. WE IMMEDIATELY DID THE MEMORY ITEMS OF THE FIRE/SMOKE/FUMES IN COCKPIT CHKLIST. I INFORMED ATC ABOUT STRONG FUMES IN THE COCKPIT AND POSSIBLE SMOKE. THE DOME LIGHT WAS TURNED ON AND NO SMOKE IN THE COCKPIT NOTICED. WE DECIDED THAT SMOKE GOGGLES WERE NOT REQUIRED YET. I CALLED THE FLT ATTENDANTS AND ASKED IF THEY OBSERVED ANY SMOKE OR FUMES. THEY INFORMED ME THAT THEY DID NOT. I DECLARED AN EMER WITH CTR AND ASKED FOR VECTORS FOR ZZZ. WE COMPLETED THE REMAINDER OF THE QRH CHECKLIST APPROXIMATELY 60 NM FROM ZZZ. I CALLED THE FLT ATTENDANTS BACK AND INFORMED THEM ABOUT THE SITUATION; THE DIVERT TO ZZZ; AND THE TIME IT WOULD TAKE TO REACH ZZZ. THEY WERE TOLD 10 - 15 MINUTES AND TO 'SECURE THE CABIN.' I WAS NOW INFORMED BY THE A FLT ATTENDANT THAT HE COULD SMELL A FAINT BURNING SMELL FROM DOWN LOW BY THE COCKPIT DOOR; BUT NO VISIBLE SMOKE IN THE CABIN. I TYPED AN ACARS TO DISPATCH THAT READ: FUMES IN COCKPIT; DIVERTING TO ZZZ. I WAS LATER TOLD ON THE PHONE WITH DISPATCH THAT HE NEVER RECEIVED THE MESSAGE. WE LATER RECEIVED AN ACARS ASKING; 'WHERE ARE YOU?' THE LAST MESSAGE WE SENT WAS: 30 NM SOUTH OF ZZZ. I MADE A PA TO THE CUSTOMERS INFORMING THEM ABOUT THE SITUATION; DIVERT TO ZZZ; AND THAT WE WOULD BE LNDG IN 10 - 15 MINUTES. I REPEATED TWICE THAT EMER VEHICLES AND PERSONNEL WOULD INSPECT OUR ACFT AFTER LNDG AND FOR THEM TO REMAIN SEATED UNTIL FURTHER INSTRUCTIONS FROM CREWMEMBERS. AFTER LANDING ON X; WE CLEARED THE RWY AT Y AND STOPPED THE ACFT FOR FIRE/RESCUE TO INSPECT THE EXTERIOR. IN AN ATTEMPT TO IMPROVE COMMUNICATION WITH EVERYONE INVOLVED; I REMOVED MY O2 MASK; BUT THE FUMES/SMELL WERE STILL TOO STRONG AND I PUT THE MASK ON AGAIN FOR THE TAXI TO THE GATE. FIRE/RESCUE FOLLOWED US TO GATE. AFTER PARKING AND COMPLETING THE CHKLIST; FIRE/RESCUE CAME UP TO THE COCKPIT TO INSPECT AND ASKED IF WE NEEDED ANY FURTHER ASSISTANCE. HE ALSO NOTICED THE SMELL OF BURNED PLASTIC OR WIRING. I MADE A PA THANKING OUR CUSTOMERS FOR BEING COOPERATIVE DURING THE EVENT AND THAT WE WERE SORRY FOR THE INCONVENIENCE; BUT THAT SAFETY IS ALWAYS OUR NUMBER ONE PRIORITY. NO VIOLATIONS OF FARS WERE REQUIRED DURING THIS EMER.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: ELECTRICAL WIRING TO THE LEADING EDGE DEVICES INDICATOR LIGHTS ON THE OVERHEAD PANEL HAD SHORTED OUT. THEY DID NOT NOTICE IF THE ASSOCIATED CIRCUIT BREAKER LIGHTS HAD POPPED.

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.