Japan Airlines (JAL) is reporting that one of their Boeing 787 Dreamliners suffered a smoking battery today, but that the plane was parked at the time of the incident

The airline also has said that the smoking was limited to the containment box protection system that Boeing engineers designed to ensure the safety of the plane in case of any battery malfunction

‘JAL reported that while the 787 was on the ground in Tokyo preparing for departure to Bangkok, with no passengers on board, a maintenance technician “in the cockpit found that the white smoke was wafting outside of the window and that the message which indicated the possibility of main battery system failure was displayed on the cockpit display

“The inspection of the battery case inside the battery enclosure revealed that the safety pressure relief valve … of one cell of the eight cells opened,” JAL said. The relief valve is supposed to open if pressure inside a cell rises. When the one valve opened, it dispersed liquid inside the plane’s main battery container, JAL said

JAL substituted another 787 and the flight departed almost on time

Boeing’s entire Dreamliner fleet was grounded last year for 3 months when a 787 operated by JAL suffered a battery fire

Boeing spokesman Doug Alder said, “We are aware of the 787 issue that occurred Tuesday afternoon at Narita, which appears to have involved the venting of a single battery cell

“The improvements made to the 787 battery system last year appear to have worked as designed,” he added. “We sincerely regret any impact caused to Japan Airlines and are working with them to return this airplane to service

The cause is under investigation, and JAL will share details with Japan’s transportation ministry and Boeing, said Seiji Takaramoto, a spokesman for the Tokyo-based carrier