A Japan Airlines (JAL) Boeing 787 Dreamliner remained grounded at Tokyo's Narita International Airport on Wednesday as regulators demanded checks to see if the aircraft was fit to fly, a day after white smoke vented from the plane and a battery cell showed signs of melting.
The incident comes a year after JAL and ANA Holdings grounded their Dreamliner fleets after separate issues with batteries overheating. All of Boeing Co's 787s were then taken out of service for more than three months while the plane manufacturer sought a fix for the problem.
ANA said its 787s were operating normally on Wednesday.
"The incident only happened yesterday, so it's difficult to say when checks, or any repairs would be complete," an official from the Japan Civil Aviation Bureau told Reuters. The agency will oversee inspections of the power pack by battery maker GS Yuasa Corp, JAL and Boeing.
The latest incident with Boeing's state-of-the-art plane, which is built with carbon-fiber composite materials and a powerful electrical system to reduce weight and improve fuel efficiency, raises fresh concerns about the plane's safety and reliability.
Boeing said it was "aware of the 787 issue that occurred Tuesday afternoon at Narita, which appears to have involved the venting of a single battery cell." Venting is the process of fumes and heat being channeled outside the battery casing and the aircraft when the battery overheats.
It noted the issue took place during scheduled maintenance with no passengers on board. "The improvements made to the 787 battery system last year appear to have worked as designed," it added. Boeing shares closed down 0.5 percent at $140.01 on the New York Stock Exchange.
The issue of who will pay for any losses incurred by keeping the jet from flying will be determined after the plane is back in the air, said a spokesman for Japan Airlines, which operates 13 Dreamliners.
Global regulators grounded all 50 Dreamliners owned by eight airlines on Jan. 16, 2013. They remained out of service while Boeing redesigned the battery, charger and containment system to ensure battery fires would not put the plane at risk. The cause of the