Fragments of the recent uncontained engine failure accident involving an American Airlines Boeing 767 at Chicago, were found up to 900 m from the runway, according to an NTSB investigative update.
The uncontained failure of a GE CF6-80C2B6 engine occurred on October 28 on a Boeing 767-300 during the take-off roll at Chicago O’Hare International Airport. An emergency evacuation of the 161 passengers and nine crewmembers onboard was conducted.
The NTSB reports that the airplane experienced an uncontained failure of the right engine about 6,550 feet from runway 28R threshold, and came to a full stop about 9,225 feet from runway 28R threshold. Preliminary FDR data show that the right engine failure occurred at an airspeed of about 128 knots with the engine operating at takeoff power.
Approximately two seconds after the engine failure, at an airspeed of about 134 knots, the takeoff was aborted. The aircraft rapidly decelerated, coming to a stop about 25 seconds after the throttle reduction.
As a result of the uncontained engine failure, a fuel leak resulted in a pool fire under the right wing. Airport Rescue and Fire Fighting personnel began applying foam within 2 minutes 51 seconds of being notified of the emergency.
The right engine stage 2 high pressure turbine disk fractured into at least 4 pieces. One piece went through the inboard section of the right wing, over the fuselage and into a UPS warehouse facility, 900 metres from the runway.
Investigation showed that one of the fractures exhibited features consistent with fatigue cracking initiating at an internal inclusion near the forward side of the hub’s inner bore. The disk had 10,984 cycles and had a life limit of 15,000 cycles.
The investigation is ongoing.