The National Transportation Safety Board on May 22 issued five safety recommendations to the FAA related to the evaluation and certification of lithium-ion batteries, as well as the certification of new technology. The recommendations evolved through the ongoing investigation of a Jan. 7, 2013, lithium-ion battery fire aboard a Boeing 787 parked at Boston Logan Airport.
Investigators found that the battery showed evidence of not only thermal runaway but also of “unintended electrical interactions that occurred among the cells, the battery case and the electrical interfaces between the battery and the airplane.”
The 12-page safety recommendation letter said that the processes used in 2006 to support the certification of the lithium-ion battery designed for the 787 were inadequate, in part, because there is no standardized thermal runaway test that is conducted in the environment and conditions that would most accurately reflect how the battery would perform when installed and operated on an in-service airplane.
However, the safety agency said the lack of a standardized thermal runaway test–one of the items the NTSB has now called for–on lithium-ion aircraft battery designs currently in service might not have adequately accounted for the hazards associated with internal short-circuiting.