WASHINGTON — Investigators are “weeks away” from determining what caused battery failures on Boeing’s grounded 787 Dreamliner jet, the head of the National Transportation Safety Board said.
“We are going to have some information tomorrow, but I think we are probably weeks away from being able to tell people ‘here’s what exactly happened and what needs to change,’ ” Deborah Hersman, NTSB chairman, said at a breakfast Wednesday with reporters in Washington.
Hersman’s comments underscore the views of U.S. regulators that a lifting of the grounding order isn’t imminent. Transportation Secretary Ray LaHood said this week that any resumption of production flights or ferry flights would wait until “the investigation is done.”
Boeing asked the Federal Aviation Administration for approval to resume test flights with the 787 while grounding orders from the agency and regulators worldwide remain in place for airlines operating Dreamliners in commercial service. The FAA is considering that request.
The safety board is looking at “the macro level to the microscopic level on this battery,” Hersman said.
Investigators are looking at each of the cells, the three windings in each of the cells and the component parts that make up the battery, she said, including tests on examples of the batteries used in the jet.
The board has evidence of short circuits in cells of the battery, “thermal runaway” and an uncontrolled chain reaction, Hersman said.
“Those features are not what we would have expected to see in a brand-new battery on a brand-new airplane,” Hersman said. “We want to make sure the design is robust and the oversight of the manufacturing process is adequate.”
Hersman declined to comment on reports she will be nominated by President Barack Obama to replace LaHood, who has said he’ll leave his position once a successor is confirmed.
Regulators and Boeing are still trying to determine what caused a battery fire on one jet and a cockpit warning that spurred an emergency landing by another, which in turn triggered grounding orders worldwide on Jan. 16.
There are inherent risks in any new technology, including lithium-ion batteries, Hersman said. That doesn’t mean the batteries are unsafe, she said.
The safety board understands that industry is going to come up with new materials, equipment and designs, Hersman said. At the same time, it wants to make sure manufacturers understand how the technology can fail and how to minimize any potential dangers, she said.
“That’s never more important than aviation,” Hersman said. “They don’t have the opportunity to pull over if there’s a fire.”