WASHINGTON (AP) — Despite a battery fire in one Boeing 787 Dreamliner and smoke in another, the type of batteries used to power the plane's electrical systems aren't necessarily unsafe — manufacturers just need to build in reliable safeguards, the nation's top aviation safety investigator said Wednesday.
National Transportation Safety Board Chairman Deborah Hersman said she doesn't want to "categorically" rule out the use of lithium ion batteries to power aircraft systems, even though it's clear that safeguards failed in the case of a Japan Airlines 787 that had a battery fire while parked at Boston's Logan International Airport last month.
"Obviously what we saw in the 787 battery fire in Boston shows us there were some risks that were not mitigated, that were not addressed," Hersman told reporters in an interview. The fire was "not what we would have expected to see in a brand new battery in a brand new airplane," she said.
The board is still weeks away from determining the cause of the Jan. 7 battery fire, Hersman said.
At the same time, Boeing received permission from the Federal Aviation Administration to fly one of its 787s from Fort Worth, Texas, to Everett, Wash., on Thursday. The permission is for a single flight for the purpose of relocating the plane, and is not a test flight, the FAA said in a statement. The FAA is still considering a separate Boeing request to conduct test flights, the agency said.
Boeing Co. spokesman Marc Birtel said that Boeing is still trying to find the cause of the battery incidents. "We are confident — as is the FAA — that the 787 is safe to operate for this activity. Safety of the crew on board is our top priority," he said in a statement.
The 787 is the first airliner to make extensive use of lithium batteries. Aircraft makers view lithium batteries, which are lighter and can store more energy than other types of batteries of an equivalent size, as an important way to save on fuel costs. The Airbus A350, expected to be ready next year, will also make extensive use of lithium ion batteries. Manufacturers are also looking to retrofit existing planes, replacing other types of batteries with lithium ion.
But lithium batteries are more likely to short circuit and start a fire than other batteries if they are damaged, if there is a manufacturing flaw or if they are exposed to excessive heat.
Investigators are also looking into the special conditions the FAArequired Boeing to meet in order to use lithium ion batteries to power the 787's electrical systems, she said.
A government-industry advisory board that works closely with the FAA issued testing standards for lithium batteries used in aircraft operations several months after the agency had approved a separate testing regime for the 787's batteries.