No one knew better than the engineers at Securaplane in Tucson, Arizona, just how dangerous it could be to perform tests on Lithium ion batteries. A fire in 2006 destroyed the company’s factory. So when testing the power charger it was producing for the Boeing 787 Dreamliner in 2007 it did not use an actual battery, making it impossible to know how the battery would perform when integrated with the charger. Testing at Thales, the French aerospace company that had the contract to develop and coordinate all the elements of the battery power system for Boeing, also failed to examine how individual components would work together.
Whether this affected Boeing’s ability to gauge the safety of the entire system and whether the design complied with federal rules, are two of many questions being asked by investigators at the National Transportation Safety Board, according to 500-plus pages of documents released to the public on Thursday.
Ever since the grounding of the 787 on 16 January raised questions about Boeing’s choice of lithium ion batteries as a power source on its newest model airplane, the plane maker has insisted it conducted extensive testing on the cobalt oxide formulation, a chemistry so volatile it required special consent from the Federal Aviation Administration to be used in aviation. But when the NTSB investigators asked Boeing, Thales and Securaplane for documentation it discovered none demonstrated “a complete life cycle of tests.”
Investigators are said to be concerned about the just how deep the battery testing went – particularly at Thales which was contracted to integrate the various components of the battery system and at Boeing, which was ultimately responsible for representing the design as safe to the FAA. Also under study is whether the FAA provided an appropriate review of Boeing’s test protocol and results, according an investigator who asked not to be identified.
“Thales didn’t go off on their own, Boeing was supposed to be following them,” the investigator said. The FAA was supposed to “oversee Boeing, and its control on Thales and GS-YUASA and Securaplane”, added the investigator.
In receiving permission to use lithium ion batteries, Boeing was required to demonstrate to the FAA that its design would reduce the chance of a smoke release from the batteries to one in ten million flight hours and the chance of an event in the battery causing the release of electrolytes to one in a billion flight hours, because an electrolyte fire can only burn itself out, it is impossible to extinguish. Boeing deemed a release of electrolytes from the battery cells, “catastrophic” in its functional hazard assessment provided to the FAA.
In addition to determining the cause of the Japan Airlines (JAL) event, NTSB chairman Deborah Hersman has repeatedly said that the safety board is eager to discover why the battery design did not met FAA criteria.
The progress report released to the public also contained several dramatic accounts by eyewitnesses and fire fighters on the scene at Boston Logan airport when the JAL battery fire was discovered. Fire fighters arrived at the aircraft to see smoke billowing out of the area where the rear battery is housed and filling the passenger cabin. Fans did not exhaust the smoke off the plane because the vents are powered by the battery, which by this time had failed. This could have implications for Boeing as it seeks permission to revise its design and get the Dreamliner flying again.
The NTSB plans a public hearing on its investigation and a forum to discuss lithium ion batteries, both to be held in April.