PAX OPENED EMER EXIT DOOR AT THE GATE WHEN SOMEONE YELLED 'FIRE.'

Narrative

WHILE PARKED ON RAMP AFTER LENGTHY DELAY EXHAUST SMOKE FROM ACFT BEING USED TO RUN OUR AIR CONDITIONING PACK WAS INGESTED INTO AIRPLANE. ACFT DOORS WERE CLOSED AND ARMED AND MANY PAX WERE ASLEEP. I SMELLED THE HVY DIESEL EXHAUST AND WAS ATTEMPTING TO GET SOMEONE OR THE RAMP TO CHK THE ACFT WHEN I GOT AN INDICATION IN THE COCKPIT THAT DOOR 2R WAS OPEN AND ALSO A L OVERWING EMER EXIT. FLT ATTENDANTS CALLED TO SAY THAT PAX HAD SMELLED THE EXHAUST AND YELLED FIRE. A PAX NEXT TO AN OVERWING EXIT AWOKE TO CRIES OF 'FIRE' AND IMMEDIATELY OPENED THE OVERWING EXIT. SHE THEN LOOKED AROUND -- SAW NO FIRE AND STOPPED. I IMMEDIATELY USED THE PA TO REASSURE THE PAX AND REQUEST THEY NOT DEPLANE. THE DOOR AT 2R HAD NOT BEEN OPENED FAR ENOUGH TO ACTIVATE THE SLIDE BEFORE A FLT ATTENDANT HAD STOPPED THE PAX. LESSONS LEARNED: SINCE WE NOW BRIEF PAX IN EXIT TOWS TO BE READY TO OPEN THE EXITS; WE MUST BE QUICK TO EXPLAIN ANY ACTIVITY WHICH MIGHT NOT BE UNDERSTOOD 'IN BACK.' AT THE FIRST SMELL OF EXHAUST FUMES FROM OUTSIDE; THE PACKS SHOULD BE TURNED OFF.