An uncontained engine failure ignited a fire that caused an American Airlines flight to be aborted before takeoff Friday afternoon at O'Hare International Airport, according to a preliminary finding by federal transportation officials.
Lorena Ward, senior investigator in charge for the National Transportation Safety Board, said 20 people on the Boeing 767 who were taken to hospitals with minor injuries were released Saturday.
Officials said 161 passengers and nine crew members were evacuated on emergency slides from the American Airlines flight headed to Miami. Thick black smoke billowed from the plane as the occupants hastily exited.
"Since we had only minor injuries, that's a pretty successful evacuation," Ward said during a news conference Saturday at O'Hare,
Ward said the preliminary investigation showed the fire started as a result of the uncontained failure of the stage 2 disk in the right engine. Investigators have yet to determine why the General Electric CF6 engine failed.
Part of the high-pressure turbine's disk hurtled into a United Parcel Service warehouse about 2,900 feet away from the plane, just south of the airport, Ward said. Another piece of disk catapulted roughly one-third of a mile north of the airplane on O'Hare property.
O'Hare firefighters applied foam to the fire within about three minutes of being informed about the emergency, Ward said. Fire damage to the fuselage was mostly limited to a grazing of the windows and cosmetic interior pieces.
"We had no fire that actually that breached the inside of the cabin," she said.
Some of the plane's 43,000 pounds of jet fuel leaked, but not all of it was consumed in the fire, authorities said.
Passengers reported a loud bang followed by massive flames on the plane's right side as the plane taxied down the runway at about 2:20 p.m. Friday. Ward said the plan was stopped about 3,000 feet before the runway ended.
"To have 3,000 feet of runway, that's a lot of runway to have left to you," Ward said.
Most of the stage 2 engine disk was recovered and will be sent to a NTSB laboratory in Washington, D.C., Ward said. Flight data and cockpit voice recorders also will be shipped to the lab.