Narrative:

After landing ewr, runway 4R with 48 souls onboard, and clear of all runways, the after landing checklist was accomplished. Approximately 60-90 seconds later, with the APU supplying the air-conditioning packs, the engine indicating/crew alerting system (EICAS) provided a 'lavatory smoke' warning. The warning sounded in the cockpit as well as on the flight attendant's panel in the galley. After identing the message and silencing the warning, the crew was contacted by the flight attendant. Captain directed her to silence the horn and investigate the lavatory status. While no smoke was initially visible, the smell of smoke was readily apparent in the cabin according to the flight attendant. Meanwhile the first officer told ground that we would need to remain stationary for a minute or two. We were, at the time, clear of the runway, and adjacent of the crash fire rescue equipment building. In the short period of time that it took the flight attendant to go back and check the lavatory, smoke slowly began to enter the cabin. Not from any one apparent source, but probably from the air-conditioning system. (It wasn't heavy smoke, but it was visible, according to the flight attendant.) the flight attendant immediately called the cockpit with this information about smoke. She made it clear that we needed to evacuate/evacuation. Captain immediately commanded 'evacuate/evacuation left side.' first officer meanwhile, declared an emergency and called for the fire trucks. Given our convenient position in front of the firehouse, trucks were on scene in seconds. Emergency personnel assisted with what was a very orderly and controled evacuate/evacuation through the main cabin door. All passenger were safely corralled on grass adjacent the aircraft and surrounded by police and emergency personnel. Appropriate QRH checklists were completed with all passenger off, emergency personnel quickly determined no fire, no more smoke, no danger. Flight attendant went on shuttle bus with passenger to terminal. Cockpit crew stayed with aircraft to assist with tow back to gate area. Maintenance had insisted on starting engine to taxi back. Captain refused. Aircraft was towed to ramp area. At final parking spot, parking and terminating checks were completed. A postflt inspection revealed no abnormalities. Aircraft was left in the secure hands of airport police. Maintenance later determined that the APU was bad, burning oil, and had probably caused the smoke.

Related reports:

Google
 

Original NASA ASRS Text

Title: FLC OF AN EMBRAER 145, EVACED THE PAX ON THE ARPT AFTER LNDG DUE TO SMOKE IN THE CABIN CAUSED BY THE ACFT'S AUX PWR UNIT.

Narrative: AFTER LNDG EWR, RWY 4R WITH 48 SOULS ONBOARD, AND CLR OF ALL RWYS, THE AFTER LNDG CHKLIST WAS ACCOMPLISHED. APPROX 60-90 SECONDS LATER, WITH THE APU SUPPLYING THE AIR-CONDITIONING PACKS, THE ENG INDICATING/CREW ALERTING SYS (EICAS) PROVIDED A 'LAVATORY SMOKE' WARNING. THE WARNING SOUNDED IN THE COCKPIT AS WELL AS ON THE FLT ATTENDANT'S PANEL IN THE GALLEY. AFTER IDENTING THE MESSAGE AND SILENCING THE WARNING, THE CREW WAS CONTACTED BY THE FLT ATTENDANT. CAPT DIRECTED HER TO SILENCE THE HORN AND INVESTIGATE THE LAVATORY STATUS. WHILE NO SMOKE WAS INITIALLY VISIBLE, THE SMELL OF SMOKE WAS READILY APPARENT IN THE CABIN ACCORDING TO THE FLT ATTENDANT. MEANWHILE THE FO TOLD GND THAT WE WOULD NEED TO REMAIN STATIONARY FOR A MINUTE OR TWO. WE WERE, AT THE TIME, CLR OF THE RWY, AND ADJACENT OF THE CFR BUILDING. IN THE SHORT PERIOD OF TIME THAT IT TOOK THE FLT ATTENDANT TO GO BACK AND CHK THE LAVATORY, SMOKE SLOWLY BEGAN TO ENTER THE CABIN. NOT FROM ANY ONE APPARENT SOURCE, BUT PROBABLY FROM THE AIR-CONDITIONING SYS. (IT WASN'T HVY SMOKE, BUT IT WAS VISIBLE, ACCORDING TO THE FLT ATTENDANT.) THE FLT ATTENDANT IMMEDIATELY CALLED THE COCKPIT WITH THIS INFO ABOUT SMOKE. SHE MADE IT CLR THAT WE NEEDED TO EVAC. CAPT IMMEDIATELY COMMANDED 'EVAC L SIDE.' FO MEANWHILE, DECLARED AN EMER AND CALLED FOR THE FIRE TRUCKS. GIVEN OUR CONVENIENT POS IN FRONT OF THE FIREHOUSE, TRUCKS WERE ON SCENE IN SECONDS. EMER PERSONNEL ASSISTED WITH WHAT WAS A VERY ORDERLY AND CTLED EVAC THROUGH THE MAIN CABIN DOOR. ALL PAX WERE SAFELY CORRALLED ON GRASS ADJACENT THE ACFT AND SURROUNDED BY POLICE AND EMER PERSONNEL. APPROPRIATE QRH CHKLISTS WERE COMPLETED WITH ALL PAX OFF, EMER PERSONNEL QUICKLY DETERMINED NO FIRE, NO MORE SMOKE, NO DANGER. FLT ATTENDANT WENT ON SHUTTLE BUS WITH PAX TO TERMINAL. COCKPIT CREW STAYED WITH ACFT TO ASSIST WITH TOW BACK TO GATE AREA. MAINT HAD INSISTED ON STARTING ENG TO TAXI BACK. CAPT REFUSED. ACFT WAS TOWED TO RAMP AREA. AT FINAL PARKING SPOT, PARKING AND TERMINATING CHKS WERE COMPLETED. A POSTFLT INSPECTION REVEALED NO ABNORMALITIES. ACFT WAS LEFT IN THE SECURE HANDS OF ARPT POLICE. MAINT LATER DETERMINED THAT THE APU WAS BAD, BURNING OIL, AND HAD PROBABLY CAUSED THE SMOKE.

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.