American Airlines Flight 383 (2016)

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American Airlines Flight 383 was a regularly scheduled passenger flight operating from Chicago O'Hare International Airport to Miami International Airport. On October 28, 2016, the Boeing 767-300ER operating the flight (registered N345AN) was accelerating for takeoff down Chicago O'Hare's runway 28R when the aircraft's right engine suffered an uncontained failure that led to a severe fire. The crew managed to abort the takeoff and evacuate everyone on board, while responding emergency services extinguished the fire. Twenty-one people were injured, and the aircraft was substantially damaged.

The right engine suffered a sudden rupture of the stage 2 disk operating at takeoff power. The disk separated into two pieces, the smaller of which pierced the wing's fuel tank and then flew 2,935 feet (895 m), falling through the roof of a United Parcel Service (UPS) facility and coming to rest on the building's floor. No UPS employees were injured.

Video American Airlines Flight 383 (2016)

Aircraft

The aircraft, a Boeing 767-323ER powered by twin General Electric CF6 engines, registration number N345AN, was delivered to American on April 16, 2003, making the aircraft thirteen years old at the time of the accident. The right hand side of the fuselage suffered considerable fire damage, and the right wing collapsed about midway along its length. American subsequently declared the hull a loss.

Maps American Airlines Flight 383 (2016)

Investigation and recommendations

In July, 2017 GE Aviation issued a Service Bulletin recommending that airlines perform regular inspections of first- and second-stage disks of all CF6 engines built prior to 2000.

On January 30, 2018, the National Transportation Safety Board (NTSB) issued its Final Report on the incident involving American 383. It traced the origin of the failure in disk 2 to a "discrete dirty white spot" that in the Board's judgement would have been undetectable, at manufacture or subsequent inspection, with the inspection techniques available. The NTSB made several safety recommendations as a result, not only with regards to the engine and aircraft but also to issues raised by the evacuation.

Engine inspections

Although the CF6 had been the subject of multiple FAA airworthiness directives, they had not focused on the larger, relatively slower disks at the front of the engine, made with a nickel alloy. Although the FAA had signaled its intent to issue an order for ultrasonic inspections of CF6-80s in September 2017, the NTSB called for such inspections to be extended to all large commercial aircraft engine models in service. It also called for increased design precautions, based on multiple uncontained disk ruptures, to be continually integrated into aircraft design, especially of the wings and fuel tanks.

Procedures

The Board recommended separate engine fire checklists for ground vs. in-flight operation; the checklist used did not so differentiate, and so did not include a separate step where, if the plane was on the ground, the other engine should be stopped to allow for evacuation. As a result, a passenger evacuating using the left overwing exit was the only person seriously injured when they were knocked to the ground by the exhaust from the still-operating engine. In addition, the checklist provided to the pilots called for discharge of only one of the two fire extinguisher bottles in the affected engine, followed by a wait of 30 seconds to judge its effectiveness; however, other checklists specific to ground operations call for immediate use of both bottles in order to create a safer environment for evacuation of the aircraft.

The Board also faulted communication efforts among the crew, including the inability of flight attendants to successfully operate the interphone (which differed from the model used in training) and the failure of the flight crew to keep attendants informed of their intention to evacuate. The Board also called for research into countermeasures against passengers evacuating with carry-on luggage despite being specifically instructed not to do so by crew.