EMER DECLARED EMER DSCNT.

Narrative

FLT ATTENDANT RPTED AN ACRID BURNING SMELL; LIKE PLASTIC BURNING; IN MAIN CABIN. PAX NOTICED ALSO AND QUERIED THE FLT ATTENDANTS ABOUT THE SMELL. THE FUMES INCREASED INTENSITY. I INITIATED THE SMOKE/FUMES CHKLIST. ACFT WAS AT FL370; 160 NM W OF DFW ON THE ARR. NEITHER CAPT NOR FO DETECTED/SMELLED THE ODOR/FUMES IN THE COCKPIT: BUT WE WENT ON 100 PERCENT OXYGEN AND DECLARED EMER WITH ATC; INITIATED A DSCNT FOR LNDG. PRIOR TO USING DEPRESSURIZATION TO EVAC FUMES FLT ATTENDANT RPTED THAT THE ODOR/FUMES HAD DISSIPATED AND WE TERMINATED THE CHKLIST PROC. WE CONTINUED A NORMAL BUT EXPEDITED ARR AND LNDG UNDER THE EMER CLRNC. THERE WAS EXCELLENT COOPERATION; COM BTWN THE FLT ATTENDANT CREW AND THE COCKPIT. PAX WERE CALM AND APPEARED TO TAKE THE EPISODE IN STRIDE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR FLIES THE MD-88 FOR A MAJOR US ACR. HE IS A FAN OF THE ASRS AND HAS DONE A LOT OF SAFETY WORK FOR HIS PLT'S UNION. HE DOES NOT KNOW EXACTLY WHAT CAUSED THE SMOKE; BUT 'PROBABLY IT WAS IN THE AIR CONDITIONING SYS.'