Narrative:

As we turned downwind for runway 36R at cvg (heading 180 degrees, IAS 180 KTS, altitude 8000 ft), we smelled a strong odor which at first appeared to come from the forward galley ovens. In conjunction with our smell of the odor, we received the emergency call from our a-line flight attendant, who told us she had smoke in the cabin from an unknown source. She had halon extinguishers standing by and remained on the interphone with us while her crew tried to find the origin of the smoke. We donned our smoke goggles and oxygen masks, declared an emergency and the copilot ran the hard card checklist for smoke and fumes from an unknown source. We flew 180 KIAS to approximately 3 mi final then slowed to 140 KIAS. On short final we slowed to vref of 127 KIAS. Since the smoke did not get any worse, we elected to clear the runway and stop on the taxiway to assess the situation. On the taxiway, the a-line flight attendant informed me that the smoke dissipated about the time that we extended the landing gear (on base leg, altitude 3000 ft, and 180 KIAS). The source of the smoke was never established. Since the smoke was gone and the threat of a fire was gone, we continued our taxi to the gate where the passenger exited the aircraft. On arrival at the gate, the fire chief came into the cockpit and said that when the passenger were off the aircraft that he would inspect the cabin (at this time the smoke was gone). The fire chief then reported that he did not find anything and said that he would turn the aircraft over to maintenance. Callback conversation with reporter revealed the following information: the reporter stated when the fire chief turned the aircraft over to maintenance and some quick checks were made it was maintenance's opinion that the problem was air conditioning pack related. The reporter said maintenance never advised its findings on what corrected the problem and the reporter did not or could not follow up. Callback conversation with reporter acn 420468 revealed the following information: the reporter stated that the problem was not related to the air conditioning packs as maintenance suspected because the odor and smoke had the characteristic of burning or overheated electrical equipment. The reporter said this aircraft when new had cabin flo light ballast shorting problems and the system was deactivated and redesigned and just now the new lighting system is being reactivated. The reporter said it may be the new flo light ballasts causing the problem.

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Original NASA ASRS Text

Title: AN MD88 AT START OF APCH AT 8000 FT DECLARED AN EMER DUE TO SMOKE AND STRONG ODOR IN COCKPIT AND CABIN. CAUSE UNKNOWN.

Narrative: AS WE TURNED DOWNWIND FOR RWY 36R AT CVG (HDG 180 DEGS, IAS 180 KTS, ALT 8000 FT), WE SMELLED A STRONG ODOR WHICH AT FIRST APPEARED TO COME FROM THE FORWARD GALLEY OVENS. IN CONJUNCTION WITH OUR SMELL OF THE ODOR, WE RECEIVED THE EMER CALL FROM OUR A-LINE FLT ATTENDANT, WHO TOLD US SHE HAD SMOKE IN THE CABIN FROM AN UNKNOWN SOURCE. SHE HAD HALON EXTINGUISHERS STANDING BY AND REMAINED ON THE INTERPHONE WITH US WHILE HER CREW TRIED TO FIND THE ORIGIN OF THE SMOKE. WE DONNED OUR SMOKE GOGGLES AND OXYGEN MASKS, DECLARED AN EMER AND THE COPLT RAN THE HARD CARD CHKLIST FOR SMOKE AND FUMES FROM AN UNKNOWN SOURCE. WE FLEW 180 KIAS TO APPROX 3 MI FINAL THEN SLOWED TO 140 KIAS. ON SHORT FINAL WE SLOWED TO VREF OF 127 KIAS. SINCE THE SMOKE DID NOT GET ANY WORSE, WE ELECTED TO CLR THE RWY AND STOP ON THE TXWY TO ASSESS THE SIT. ON THE TXWY, THE A-LINE FLT ATTENDANT INFORMED ME THAT THE SMOKE DISSIPATED ABOUT THE TIME THAT WE EXTENDED THE LNDG GEAR (ON BASE LEG, ALT 3000 FT, AND 180 KIAS). THE SOURCE OF THE SMOKE WAS NEVER ESTABLISHED. SINCE THE SMOKE WAS GONE AND THE THREAT OF A FIRE WAS GONE, WE CONTINUED OUR TAXI TO THE GATE WHERE THE PAX EXITED THE ACFT. ON ARR AT THE GATE, THE FIRE CHIEF CAME INTO THE COCKPIT AND SAID THAT WHEN THE PAX WERE OFF THE ACFT THAT HE WOULD INSPECT THE CABIN (AT THIS TIME THE SMOKE WAS GONE). THE FIRE CHIEF THEN RPTED THAT HE DID NOT FIND ANYTHING AND SAID THAT HE WOULD TURN THE ACFT OVER TO MAINT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED WHEN THE FIRE CHIEF TURNED THE ACFT OVER TO MAINT AND SOME QUICK CHKS WERE MADE IT WAS MAINT'S OPINION THAT THE PROB WAS AIR CONDITIONING PACK RELATED. THE RPTR SAID MAINT NEVER ADVISED ITS FINDINGS ON WHAT CORRECTED THE PROB AND THE RPTR DID NOT OR COULD NOT FOLLOW UP. CALLBACK CONVERSATION WITH RPTR ACN 420468 REVEALED THE FOLLOWING INFO: THE RPTR STATED THAT THE PROB WAS NOT RELATED TO THE AIR CONDITIONING PACKS AS MAINT SUSPECTED BECAUSE THE ODOR AND SMOKE HAD THE CHARACTERISTIC OF BURNING OR OVERHEATED ELECTRICAL EQUIP. THE RPTR SAID THIS ACFT WHEN NEW HAD CABIN FLO LIGHT BALLAST SHORTING PROBS AND THE SYS WAS DEACTIVATED AND REDESIGNED AND JUST NOW THE NEW LIGHTING SYS IS BEING REACTIVATED. THE RPTR SAID IT MAY BE THE NEW FLO LIGHT BALLASTS CAUSING THE PROB.

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.