What happened
On May 27, 2016, at approximately 12:38 JST, a Korean Air Lines Co., Ltd. Boeing 777-300, registered HL7534, was performing a scheduled takeoff roll on runway 34R at Tokyo International Airport (Haneda) bound for Gimpo International Airport. During the takeoff roll, a fire warning activated for the No.1 (left-side) engine. The flight crew immediately initiated a rejected takeoff, bringing the aircraft to a stop on the runway. Due to the engine fire, the crew conducted an emergency evacuation of the aircraft. The flight carried 319 people, including 302 passengers and 17 crew members; during the evacuation, 40 passengers sustained slight injuries.
The investigation
The Japan Transport Safety Board (JTSB) conducted an extensive investigation involving engine teardown inspections, laboratory analysis of turbine disks, and examinations of the manufacturing process. Investigators examined the No.1 engine, specifically looking for evidence of foreign object damage or mechanical failure. The investigation included microscopic analysis of the fracture surfaces using Scanning Electron Microscopy (SEM) to identify fatigue patterns. The scope of the inquiry extended to the manufacturing of the high-1st stage high pressure turbine (HPT) disk and the effectiveness of subsequent maintenance inspections by the operator.