A fatigue crack in the high-pressure compressor stage 8 disk web was the cause of a September 2015 engine failure and fire on a British Airways 777-236ER, according to the National Transportation Safety Board (NTSB).
The crack also caused the main fuel supply line to detach.
The jet was in takeoff roll at McCarran International Airport in Las Vegas when the cockpit crew heard a “bang.” The captain aborted the takeoff, and all the passengers and crew were evacuated via emergency slides. There were no injuries.
The evacuation occurred on the right side of the aircraft. This was the side of the unaffected engine, and the engine continued to run for 43 seconds after the evacuation order. As a result, the jet blast blew two emergency slides out of position, making them useless for the evacuation.
The jet’s occupants were able to evacuate before smoke and fire filled the fuselage.
The NTSB also found that captain failed to use his quick reference handbook to read and do checklist items.
“Because the captain did not follow standard procedures, his call for the evacuation checklist and the shutdown of the right engine were delayed,” the NTSB said.
The high-pressure compressor stage 8-10 spool in the left engine had accumulated 11,459 cycles with investigators finding that the crack initiated after approximately 6,000 cycles – much earlier than the engine’s manufacturer, GE, had anticipated. The cause of the crack could not be identified.
Additionally, the disk web is not an area that either the Federal Aviation Administration or GE required to be inspected routinely. After the accident, however, GE implemented such inspection protocol for disk web maintenance.