Investigation Summary
The accident occurred as the Boeing 767 was accelerating through approximately 134 knots. The uncontained failure of the General Electric CF6-80C2B6 engine's HPT stage 2 disk was catastrophic: one large fragment traveled nearly 3,000 feet and crashed through the roof of a nearby UPS facility. The resulting fire on the right side of the aircraft was fed by a significant fuel leak from the breached wing tank. During the emergency response, a breakdown in communication and checklist execution occurred. The flight crew followed a standard engine fire checklist that did not differentiate between ground and in-flight scenarios, leading to a delay in shutting down the left engine. Simultaneously, flight attendants initiated an evacuation before the left engine was secured. A passenger who exited via the left overwing exit was blown off the wing by the engine's exhaust, resulting in serious injuries. The NTSB investigation highlighted that the disk failure was caused by low-cycle fatigue cracks originating from a manufacturing anomaly known as a 'discrete dirty white spot,' which was undetectable by the inspection protocols in place at the time.
Final Conclusions
The NTSB determined the probable cause was the failure of the HPT stage 2 disk, which breached the fuel tank and caused a fire. The failure originated from an internal manufacturing anomaly. Contributing to the injuries were the delay in shutting down the left engine, a lack of ground-specific fire checklists for the Boeing 767, and a flight attendant's deviation from procedures by evacuating passengers while the left engine was still running. The investigation concluded with the release of report NTSB/AAR-18/01 on January 30, 2018.
Video Analysis
American Airlines 383 Uncontained Engine Failure - The ... — Detailed breakdown of the uncontained engine failure and subsequent fire during the takeoff roll of American Airlines Flight 383 at Chicago O'Hare.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Anthony Kochenash, age 61. Joined American Airlines in May 2001. Previously flew for TWA (1986-2001) and served in the USAF (1978-1985) flying KC-135 and CT-39 aircraft.
First Officer
David Ditzel, age 57. Joined American Airlines in May 2001. Previously flew for TWA (1995-2001).
Systems & Failure Modes
General Electric CF6-80C2B6 Engine
The right engine suffered an uncontained failure of the stage 2 high-pressure turbine disk due to internal fatigue cracking.
Boeing 767 Engine Fire Checklist
The checklist at the time did not distinguish between ground and air fires, leading the pilots to perform steps that delayed the shutdown of the non-affected engine.
Cabin Interphone System
Flight attendants struggled to use the interphone to communicate with the cockpit because the model differed from the one used in their training.
Interesting Facts
- 01The aircraft was a Boeing 767-323(ER) delivered in 2003.
- 02A fragment of the failed turbine disk was found 2,935 feet away inside a UPS warehouse.
- 03The failed HPT stage 2 disk had 10,984 cycles, well below its 15,000-cycle life limit.
- 04The fire was so intense that the right wing eventually collapsed midway along its length.
- 05The aircraft was declared a total hull loss, the 17th for the Boeing 767 type and the first 767-300ER hull loss for American Airlines.
Safety Actions & Advisories
FAA Airworthiness Directive 2018-15-04
Required ongoing ultrasonic inspections for cracks in stage 1 and stage 2 disks on CF6-80 series engines.
Checklist Revision
The NTSB recommended that Boeing and operators create separate engine fire checklists for ground operations to ensure immediate shutdown of all engines before evacuation.
Evacuation Research
The NTSB called for research into countermeasures to prevent passengers from evacuating with carry-on luggage, which obstructed the exit process during this accident.