Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
General Evacuated
Aircraft
We were taxiing for takeoff; when we received 6 chimes from the lead flight attendant. I picked up the interphone; as the captain was driving the airplane. The lead FA informed me that there was smoke coming from an overhead bin; and that they were investigating. I told her that we would stop on the taxiway and she should call us back immediately with any new information. She called us back moments later to let us know that the smoke seemed to be coming from underneath the baggage bin; from either the vents or the passenger service unit. They informed us that they were moving passengers away from that area; and that they were going to discharge halon extinguishers into the overhead area where the smoke was coming from. I asked the lead FA to stay on the interphone and keep us updated as to what was going on. She then said that the extinguishing agent seemed to diminish the smoke and that it was dissipating. I told her that we would return to the gate immediately; and asked her to please inform us immediately if there was any further problems or changes in the situation. We coordinated with ground control and ops to return to the gate; and began taxiing. We turned left onto a taxiway and just as we made the turn; we again received 6 chimes from the cabin. When I picked up the interphone; our lead FA said the smoke had returned; it was worse than before and was spreading. Her voice was quavering; and she said that passengers were beginning to panic. At this point another FA in the rear of the plane got on the interphone as well. I asked them both if they thought we needed to evacuate. They both answered affirmatively. The captain; upon hearing this; stopped the plane; set the parking brake; and told ground control that we were evacuating on the taxiway; and to please have emergency equipment dispatched immediately. The captain and I ran the Evacuation Checklist on the back of the QRH; and then we exited the cockpit to assist in the evacuation. I went out the galley door/slide; and helped people at the bottom coming off of the slide; until no more passengers emerged from that exit. I then made my way to the left wing; as I did not witness any passengers on the right wing. Passengers were coming off of both the front and aft part of the wing. I instructed some of the elderly passengers to exit the rear of the wing; and some complied; but many passengers continued to slide down the front of the wing. The entire evacuation took approximately 2 minutes; and was handled very well by our cabin crew.
During taxi for takeoff; a Flight Attendant notified the flight crew of smoke coming from an overhead bin. After receiving updates from the flight attendants about the smoke continuing to intensify even after fire bottle discharge; crew requested fire equipment and evacuated the aircraft on the taxiway.