Narrative:

While descending; I detected the scent of electrical smoke. I queried my first officer and he confirmed the strong smell of electrical smoke. I called the flight attendants on the intercom and queried them as well. They confirmed the presence of a strong smell of an acrid; electrical smell and advised that smoke was entering the cabin. I advised the flight attendants that we would declare an emergency; to prepare the cabin for landing; and that we would be on the ground in approximately 5-10 minutes (emergency briefing). I assigned flying duties to the first officer and ordered him to declare an emergency; fly directly to airport and to fly there as fast as he dared. ATC was most accommodating; and granted our requests. While first officer descended and accelerated; I accomplished the 'cabin fire I smoke' and the 'smoke I fumes removal' checklists in accordance with the dc-9 operating manual QRH. I also briefed the passengers on the situation. Reports from the flight attendants indicated that initially; the smoke abated; but then returned. Landing was uneventful. Exited runway; stopped aircraft; told everyone to remain in their seats via the PA; and contacted airport rescue and fire fighting. They scanned the airplane with thermal cameras and could not detect any heat source (other than the engines; of course...) smoke was still present and increasing in cabin. I elected to taxi expeditiously to gate where crews and agents were waiting. Passengers safely deplaned through main cabin door. Aircraft was taken out of service. Passengers rebooked. As of this writing; the source of the smoke was undetermined.

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Original NASA ASRS Text

Title: A MD80 developed smoke and fumes in the cockpit and cabin during descent. An emergency was declared and the aircraft expedited to the destination. The cause of the smoke was believe to be either a fluorescent ballast or an under seat power port.

Narrative: While descending; I detected the scent of electrical smoke. I queried my First Officer and he confirmed the strong smell of electrical smoke. I called the Flight Attendants on the intercom and queried them as well. They confirmed the presence of a strong smell of an acrid; electrical smell and advised that smoke was entering the cabin. I advised the Flight Attendants that we would declare an emergency; to prepare the cabin for landing; and that we would be on the ground in approximately 5-10 minutes (emergency briefing). I assigned flying duties to the First Officer and ordered him to declare an emergency; fly directly to airport and to fly there as fast as he dared. ATC was most accommodating; and granted our requests. While First Officer descended and accelerated; I accomplished the 'Cabin Fire I Smoke' and the 'Smoke I Fumes Removal' checklists in accordance with the DC-9 Operating Manual QRH. I also briefed the passengers on the situation. Reports from the Flight Attendants indicated that initially; the smoke abated; but then returned. Landing was uneventful. Exited Runway; stopped aircraft; told everyone to remain in their seats via the PA; and contacted Airport Rescue and Fire Fighting. They scanned the airplane with thermal cameras and could not detect any heat source (other than the engines; of course...) Smoke was still present and increasing in cabin. I elected to taxi expeditiously to gate where crews and agents were waiting. Passengers safely deplaned through main cabin door. Aircraft was taken out of service. Passengers rebooked. As of this writing; the source of the smoke was undetermined.

Data retrieved from NASA's ASRS site as of April 2012 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.