The battery fire that led to the grounding of Boeing’s Dreamliner fleet last year was caused by inadequate design and testing, according to the final report by the US National Transportation Safety Board (NTSB).
The lithium-ion battery fire occurred on January 7, 2013 on a Japan Airlines 787 Dreamliner while the plane sat at Boston’s Logan International Airport.
The investigations by the NTSB showed that the battery failure resulted from an internal short circuit that occurred in one of the two lithium batteries on board which led to thermal runaway that engulfed the entire power pack.
The NTSB criticised battery supplier GS Yuasa in the report and stated that an inadequate cell manufacturing process allowed these defects that cause internal short-circuiting, including wrinkles in electrolyte and foreign object debris.
Earlier, Boeing had certified that overheating in one cell of the lithium-ion battery could not spread to others and the Federal Aviation Administration (FAA) approved the design and testing. The NTSB critised both parties in the final report, finding shortcomings in the FAA’s guidance to manufacturers on factors to consider in safety assessments of equipment.
Further, Boeing failed to incorporate design requirements in the 787 main and auxiliary power unit battery specification control, the NTSB said.
“We appreciate and respect the NTSB’s final report, although the root cause of this internal short circuit remains elusive,” said a GS Yuasa spokesman, after the NTSB issued the report.
The final report can be downloaded here.