A 2015 engine fire on a British Airways 777-236ER was caused by a fatigue crack in the high-pressure compressor stage 8 disk web and subsequent uncontained engine failure, which led to the detachment of the main fuel supply line, the National Transportation Safety Board found Wednesday.​





The September 8, 2015 fire occurred during the takeoff roll at McCarran International Airport in Las Vegas. Two seconds after hearing a “bang,” the captain aborted the takeoff, and the jetliner came to a stop on the runway 13 seconds later. The 157 passengers, including one lap child, and 13 crewmembers evacuated via emergency slides. The flight’s destination was London-Gatwick Airport.



The captain ordered passengers to evacuate from the right side of the airplane. But the NTSB found that the unaffected right engine continued to run for 43 seconds after the captain’s order, resulting in jet blast blowing two emergency slides out of position and rendering them unusable for the evacuation. The passengers and crew were able to use two of the eight doors to leave the airplane before smoke and fire encroached the fuselage.











The left engine of the 777-236ER after the fire. (Photo: NTSB)



The NTSB found that the captain did not use his quick reference handbook to read and do checklist items. It was only when a third pilot in the cockpit noticed instruments indicating the right engine was still running that the engine was shut down. “Because the captain did not follow standard procedures, his call for the evacuation checklist and the shutdown of the right engine were delayed,” the report said.



The high-pressure compressor stage 8-10 spool in the left engine, one of two GE GE90-85BG11 engines on the airplane, had accumulated 11,459 total cycles. Investigators found that the crack initiated after about 6,000 cycles, much earlier than the engine’s manufacturer, GE, predicted; the cause of the crack initiation could not be identified. There were no additional cracks found on the disk during a post-accident inspection of the engine.



The disk web was not an area that either the Federal Aviation Administration or the manufacturer required to be inspected, so the crack went undetected. During maintenance in September 2008, when the high-pressure compressor was removed from the engine and disassembled, exposing the stage 8-10 spool, the surface crack length would have been about 0.05 inches. “If the disk web had been required to be inspected during this maintenance, the crack should have been detectable,” the report said. The lack of inspection procedures for the stage 8 disk contributed to the accident, the NTSB found. After the accident, GE implemented inspection procedures designed to detect disk web cracks.



The full report can be found here or on NTSB.gov.​