HEAVY SMOKE DEVELOPS IN CABIN OF WDB. CAPT DECIDES TO EVACUATE PASSENGERS.

Narrative

FLT FROM GENEVA TO PARIS LANDED ON RWY 28. AFTER LEAVING THE RWY AND IN CONTACT WITH GND CTL THE CAPT RPTED SMELLING SMOKE AND INSTRUCTED THE F/E TO CHK THE AIR CONDITIONING PACKS. AT THIS TIME THE FLT SVC MGR CAME IN THE COCKPIT RPTING HEAVY SMOKE IN THE CABIN. THE F/E WAS UNABLE TO DETERMINE THE SOURCE. THE CAPT INSTRUCTED THE F/E TO INITIATE THE APPROPRIATE CHKLIST. THE CREW WENT ON O2. I WAS INSTRUCTED TO INFORM GND CTL OF THE SITUATION AND THAT WE WERE STOPPING THE ACFT AND TO STANDBY WITH THE EMER EQUIP. AS I TURNED TO LOOK BACK AT THE F/E PANEL; I NOTICED A PACK FLOW #3 CB POPPED. WE FELT THIS WAS THE PROB AREA. ON STOPPING THE CAPT MADE A PAX ANNOUNCEMENT TELLING THE PAX WE WERE WORKING ON THE PROB. THE SMOKE REMOVAL CHKLIST WAS PERFORMED WITH SLOW RESULTS. THE FLT SVC MGR RPTED SMOKE STILL HEAVY; THE PAX WERE VERY NERVOUS AND STARTING TO STAND. OPENING THE ACFT DOORS TO RID THE SMOKE W/O ENGAGING THE SLIDES WAS BRIEFLY CONSIDERED; BUT NOT BEING TOTALLY SURE OF THE SOURCE BEING TOTALLY CONTAINED AND A SUBSEQUENT ELECTRICAL PROB WOULD PUT US IN A SITUATION OF NOT BEING ABLE TO RECLOSE THE DOORS AND ENGAGING THE SLIDES. THE CAPT INITIATED AN EVAC. THE P/A AND THE EVAC ALARM WERE USED. GND CTL WAS ADVISED AND EMER EQUIP WAS ON THE SCENE. THE EMER EVAC CHKLIST WAS READ TO BE SURE NOTHING WAS MISSED DURING THE PROC. I WAS THEN SENT BACK TO THE CABIN. THE LAST FEW PAX WERE LEAVING THE ACFT. I CHKED WITH THE CABIN TEAM TO BE SURE ALL PAX WERE OFF. I INSPECTED THE CABIN; ALL SLIDES HAD OPERATED PROPERLY. THE SLIDE ON L2 DOOR WAS NOT USED DUE TO A 15 KT WIND WHICH TWISTED IT ABOUT 30 DEGS. I RETURNED TO COCKPIT. MINOR INJURIES WERE RPTED DURING THE EVAC--NONE SERIOUS. ALL PAX CONTINUED TO THEIR DESTINATIONS. THIS WAS THE FIRST EVAC ANY OF US HAD BEEN THROUGH. A SEEMINGLY NORMAL FLT LEG; NORMAL LNDG AND TAXI OFF THE RWY. FIVE MINS LATER THE ACFT WAS EVACUATED. LATER THAT DAY MAINT FOUND A FAULTY PACK VALVE AND ELECTRICAL CIRCUITRY. THE SMOKE FILLED THE CABIN VERY FAST. THE SMOKE REMOVAL PROC ON THIS ACFT WOULD BE EFFECTIVE IN THE AIR BUT ON THE GND WITH NO DIFFERENTIAL PRESSURE IT WAS TOTALLY INEFFECTIVE. IF THE EVAC HAD NOT BEEN INITIATED WHEN IT WAS WE FELT THAT A CABIN ATTENDANT; OR IN THE MOST UNDESIRABLE A PANICKED PAX WOULD START IT. THE EVAC ALARM AND THE SMOKE ALARM HINDERED MANY FROM HEARING THE CAPT'S PAX ANNOUNCEMENT. IT'S MY ESTIMATE THAT 149 PAX WERE EVACUATED IN LESS THAN 90 SECS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR SAID THAT THE SMOKE ALARMS WERE ALL LOCATED IN LAVS AND THAT THERE WAS NO CONTROL OVER THEM. WHEN ASKED IF HE THOUGHT THE SMOKE/EVAC ALARMS SHOULD BE TURNED OFF OR BE MUTED WHEN THE P/A WAS IN USE; HE SAID NO. HE DID SAY THAT WHEN THE WORD 'FIRE' IS USED DURING THE PAX ANNOUNCEMENT THAT IT MIGHT BE TAKEN OUT OF CONTEXT BY THE PAX BECAUSE THE ENTIRE SENTENCE COULD NOT BE HEARD AND THIS MIGHT LEAD TO A PANIC SITUATION. AFTER THE HEARING; ACR MGMNT THOUGHT THEIR DECISION TO EVAC WAS THE PROPER ONE TO MAKE. THE PACK OVERHEAT LIGHT WAS ON THE SAME CB THAT CTLED THE PACK VALVE WHICH MADE IT HARDER TO PROPERLY DIAGNOSE THE PROB. THE PACK COULD NOT BE TURNED OFF BUT THE ENG COULD HAVE BEEN SHUT DOWN.