A US air safety chief has issued a “very serious air safety concern” over a battery fire on a Japan Airlines (JAL) Boeing 787 Dreamliner.
US National Transportation Safety Board (NTSB) chairman Deborah Hersman spoke as the board published its preliminary findings into the fire yesterday.
She said the battery had spewed out very hot, molten electrolytes, despite the presence of numerous systems meant to prevent such an event.
The battery had experienced both some short circuits and a “thermal runaway” – rapid heating. The board was still working to determine what had caused the events, the Financial Times reported.
Another 787 – operated by All Nippon Airlines – was forced to make an emergency landing in Takamatsu, western Japan, because of smoke coming from a battery.
The US Federal Aviation Authority then ordered a grounding of all 787s in the country, a ruling followed by other regulators worldwide.
The NTSB is conducting an investigation into the JAL fire on January 7 at Boston’s Logan Airport. The FAA is in charge of certifying whether aircraft are safe to fly.
Hersman said: “The expectation in aviation is to never experience a fire onboard an aircraft.
“In two weeks … we saw two cases of battery failure on a 787 and the grounding of the entire fleet by the FAA.”
It was “all hands on deck” at the NTSB to determine what had gone wrong with the battery, Hersman added.
“Obviously, this is an unprecedented event. We are very concerned. This is a very serious air safety concern. The FAA has taken very serious action.”
Hersman also stressed the complexity of the investigation and the novelty of the lithium-ion battery technology involved, suggesting the investigation was likely to prove lengthy.
Thomson Airways and British Airways are due to take delivery of their first Dreamliners in May.
Boeing welcomed progress in the investigation and said it was working tirelessly with its customers and regulators to resolve the problem.
“Boeing deeply regrets the impact that recent events have had on the operating schedules of our customers and their passengers,” the manufacturer said.