US authorities have recommended the Federal Aviation Administration (FAA) adopt aircraft-specific lithium-ion battery tests and other measures to evaluate the risk of internal short circuits, following the infamous Boeing Dreamliner incident.
The US National Transportation Safety Board (NTSB) is conducting an ongoing investigation of a fire event that occurred in January 2013 of a lithium-ion battery on a Boeing 787 parked at Boston Logan Airport.
In a letter to the FAA, the National Transportation Safety Board (NTSB) has said that the processes used in 2006 to support the certification of the GS Yuasa lithium-ion battery designed for the Boeing 787 were inadequate, in part, because there is no standardised thermal runaway test conducted in the environment and conditions that would most accurately reflect how the battery would perform when installed and operated.
Investigators found the battery involved showed evidence not just of an internal thermal runaway but that “unintended electrical interactions occurred among the cells, the battery case, and the electrical interfaces between the battery and the airplane.”
The NTSB said that including subject matter experts outside of the aviation industry “could further strengthen the aircraft certification process” by ensuring that both the FAA and the aircraft manufacturer have access to the most current research and information related to the developing technology.
In the letter to the FAA, the NTSB recommended five measures including developing an aircraft-level thermal runaway test to demonstrate safety performance in the presence of an internal short circuit failure; Requiring the above test as part of certification of future aircraft designs; Re-evaluating internal short circuit risk for lithium-ion batteries now in-service; Developing guidance for thermal runaway test methods; Include a panel of independent expert consultants early in the certification process for new technologies installed on aircraft.
The final report on the January 2013 Boston 787 battery fire investigation is estimated to be completed in the autumn.