Narrative:

While en route dfw/sdf at FL330 the first officer and I both noticed a strong odor in the cockpit suggesting an electrical burning component, location unknown. No abnormal indications were noted and no circuit breakers popped. Within seconds, the senior flight attendant in the cabin called to inform me of the same odor in the main cabin, noting that the galleys were secure and the problem was not originating from that location. No smoke was visible in either the cockpit or cabin. I immediately asked the first officer to get a clearance from ZME into lit, approximately 15 mi southeast of our position, with an immediate descent. An uninterrupted descent ensued with clearance from the center and no emergency was declared. The cockpit/cabin fire/smoke checklist was run as a precaution, and the odor began to diminish after about 5 mins. Coordinated the time remaining with the #1 flight attendant and got updates on the cabin condition during the descent. Landed straight-in on lit runway 22L on a visual approach. WX was perfect. Time from initial notice of odor until landing was about 7 mins. Crash fire rescue equipment was routinely present but no assistance was needed, and at no time did an evacuate/evacuation appear necessary. After landing, I checked with the flight attendant to get a new cabin assessment and she said the odor had abated substantially. A non revenue pilot in the cabin also verified the odor as electrical in nature. We parked at the gate and contract maintenance subsequently found a possible cause but could not say for sure what the culprit was. They discovered a dc power supply cooling fan had failed, but there was no odor detected within the unit although it was still noticeable in the cockpit.

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Original NASA ASRS Text

Title: F100 DIVERTS TO LIT WITH ELECTRICAL SMOKE IN COCKPIT AND CABIN.

Narrative: WHILE ENRTE DFW/SDF AT FL330 THE FO AND I BOTH NOTICED A STRONG ODOR IN THE COCKPIT SUGGESTING AN ELECTRICAL BURNING COMPONENT, LOCATION UNKNOWN. NO ABNORMAL INDICATIONS WERE NOTED AND NO CIRCUIT BREAKERS POPPED. WITHIN SECONDS, THE SENIOR FLT ATTENDANT IN THE CABIN CALLED TO INFORM ME OF THE SAME ODOR IN THE MAIN CABIN, NOTING THAT THE GALLEYS WERE SECURE AND THE PROB WAS NOT ORIGINATING FROM THAT LOCATION. NO SMOKE WAS VISIBLE IN EITHER THE COCKPIT OR CABIN. I IMMEDIATELY ASKED THE FO TO GET A CLRNC FROM ZME INTO LIT, APPROX 15 MI SE OF OUR POS, WITH AN IMMEDIATE DSCNT. AN UNINTERRUPTED DSCNT ENSUED WITH CLRNC FROM THE CTR AND NO EMER WAS DECLARED. THE COCKPIT/CABIN FIRE/SMOKE CHKLIST WAS RUN AS A PRECAUTION, AND THE ODOR BEGAN TO DIMINISH AFTER ABOUT 5 MINS. COORDINATED THE TIME REMAINING WITH THE #1 FLT ATTENDANT AND GOT UPDATES ON THE CABIN CONDITION DURING THE DSCNT. LANDED STRAIGHT-IN ON LIT RWY 22L ON A VISUAL APCH. WX WAS PERFECT. TIME FROM INITIAL NOTICE OF ODOR UNTIL LNDG WAS ABOUT 7 MINS. CFR WAS ROUTINELY PRESENT BUT NO ASSISTANCE WAS NEEDED, AND AT NO TIME DID AN EVAC APPEAR NECESSARY. AFTER LNDG, I CHKED WITH THE FLT ATTENDANT TO GET A NEW CABIN ASSESSMENT AND SHE SAID THE ODOR HAD ABATED SUBSTANTIALLY. A NON REVENUE PLT IN THE CABIN ALSO VERIFIED THE ODOR AS ELECTRICAL IN NATURE. WE PARKED AT THE GATE AND CONTRACT MAINT SUBSEQUENTLY FOUND A POSSIBLE CAUSE BUT COULD NOT SAY FOR SURE WHAT THE CULPRIT WAS. THEY DISCOVERED A DC PWR SUPPLY COOLING FAN HAD FAILED, BUT THERE WAS NO ODOR DETECTED WITHIN THE UNIT ALTHOUGH IT WAS STILL NOTICEABLE IN THE COCKPIT.

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.