WASHINGTON — Lithium batteries that can leak corrosive fluid and start fires have emerged as the chief safety concern involving Boeing's 787 Dreamliner, a problem that apparently is far more serious than government or company officials acknowledged less than a week ago.
The Federal Aviation Administration late Wednesday grounded Boeing's newest and most technologically advanced jetliner until the risk of battery fires is resolved. The order applies only to the six Dreamliners operated by United Airlines, the lone U.S. carrier with 787s. Airlines and civil aviation authorities in other countries quickly followed suit.
Japan's two largest air carriers voluntarily grounded their 787s on Wednesday ahead of the FAA's order following an emergency landing by one of the planes in Japan. On Thursday, the European Aviation Safety Agency ordered all European carriers to ground the jetliner. The Indian government ordered Air India to ground its fleet of six Boeing 787s, and Ethiopian Airlines grounded its four 787s.
As details emerged of two battery failures only 10 days apart, it became apparent that the FAA wouldn't be able to wait for completion of its safety review before taking action. An inspection of the All Nippon Airways 787 that made an emergency landing in western Japan found that electrolytes, a flammable battery fluid, had leaked from the plane's main lithium-ion battery. Investigators found burn marks around the damage. Japan's Kyodo News agency quoted transport ministry investigator Hideyo Kosugi as saying the liquid leaked through the electrical room floor to the outside of the aircraft.
In the first battery incident Jan. 7, it took firefighters 40 minutes to put out a blaze centered in an auxiliary power unit of a Japan Airlines 787. The plane was empty of passengers shortly after landing at Boston's Logan International Airport.
The two incidents resulted in the release of flammable electrolytes, heat damage and smoke, the FAA confirmed. The release of battery fluid is especially concerning, safety experts said. The fluid is extremely corrosive, which means it can quickly damage electrical wiring and components. The 787 relies far more than any other airliner in operation on electronics to function rather than hydraulic or mechanical systems.
The electrolyte fluid also conducts electricity, so as it spreads it can short circuits, interfere with electrical signals and make control of the plane impossible for pilots and ignite fires.
The fluid leak identified in the Japanese airline plane was a "very significant finding," said John Goglia, an expert on aircraft maintenance and a former National Transportation Safety Board member.
"There are all kinds of possibilities," Goglia said. "They need to go in and take a look at it. I guarantee you everybody's doing that."
The 787 is the first airliner to make extensive use of lithium-ion batteries to help power its energy-hungry electrical systems. The batteries charge faster and can be better molded to space-saving shapes compared with other airplane batteries.
Jim McNerney, Boeing's chairman, president and CEO, said the company is working with the FAA to resolve the situation as quickly as possible.
"We are confident the 787 is safe and we stand behind its overall integrity," he said in a statement.
Boeing and its customers will need to move quickly to resolve the problem. The aircraft maker has booked orders for more than 800 of the planes from airlines around the world attracted by its increased fuel efficiency.