Investigation found, A rotating disk within the GE – CF6-80 engine had an “internal inclusion,” meaning foreign debris became embedded within the nickel- and chromium-based alloy designed to withstand the heat and high stresses of a jet engine,
The engine that failed was built in 1997, according to GE.
The terminal camera video released by NTSB
As part of its ongoing investigation of an Oct. 28, 2016, uncontained engine failure on American Airlines flight 383, the NTSB issued an investigative update in Nov 2016.
The uncontained failure of a GE CF6-80C2B6 engine occurred on a Boeing 767-300 (N345AN) during the take-off roll at Chicago O’Hare International Airport. An emergency evacuation of the 161 passengers and nine crewmembers onboard was conducted.
Initial findings include the following:
The accident flight started its takeoff roll on runway 28R at the intersection with taxiway N5.
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 left and right engine throttle lever angles decreased rapidly. Coincident with the throttle movement, brake pressure rose in a manner consistent with maximum autobrake application; the auto speedbrakes were extended.
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