Japan Airlines Co. is investigating what caused a battery on a Boeing Co. 787 Dreamliner to smoke during preflight maintenance, a year after a fire on one of the carrier’s jets helped spur the grounding of the global fleet.
Mechanics found that one of eight battery cells had vented liquid through a safety valve yesterday, while the others were intact, said Seiji Takaramoto, a JAL spokesman. Instruments in the cockpit showed a possible fault in a main battery and a main battery charger, he said.
The incident is the first sign of a battery failure since Boeing redesigned the units after a pair of meltdowns on 787s, one flown by JAL and the other by ANA Holdings Inc. U.S. safety regulators said yesterday that they were working with peers in Japan to review the episode, which occurred on an empty jet at Tokyo’s Narita airport.
“Damage was limited to one cell,” said Hans Weber, president of Tecop International Inc., a San Diego-based consultant. “Something was wrong and fumes vented, as they are supposed to be. Very importantly, the system designed to isolate these neighboring battery cells from one another worked also.”
Smoke was detected under the 787 during routine maintenance before a flight to Bangkok, spurring the hunt for the source, Takaramoto said by telephone. Tokyo-based JAL switched out that Dreamliner with another 787 for the flight, he said.
The two failures of lithium-ion batteries on Dreamliners in January 2013 prompted regulators worldwide to order the jets parked while Chicago-based Boeing crafted a fix. ANA and JAL are the biggest Dreamliner operators, and they felt the brunt of the three-month grounding as they rushed to substitute planes for their idled 787s. Airbus SAS won its first JAL order in October.
A decline in Boeing’s stock of only 0.5 percent to $140.01 yesterday in New York showed investor confidence that the “fix worked,” Howard Rubel, a Jefferies Inc. analyst in New York, said in an e-mail. He rates Boeing shares a buy.
The FAA said it’s working with Boeing and the Civil Aviation Bureau of Japan, while the U.S. National Transportation Safety Board said it’s also aware of the case and is working with the Japan Transport Safety Board.
Boeing regrets “any impact” to JAL, Marc Birtel, a spokesman, said by e-mail. “Since certification of the enhanced 787 battery system in 2013, and the return to service of the 787 fleet, this is the first indication of a battery cell failure.”
Dreamliners at Chicago-based United Airlines, the largest North American customer, “are operating normally,” said Christen David, a spokeswoman. “We have not experienced any issues with our batteries.”
Last year’s grounding only added to a history of setbacks for the Dreamliner, whose commercial debut in 2011 for Tokyo-based ANA was more than 3 1/2 years late because of production snags and other delays.
It’s the first jetliner built chiefly of composite materials rather than traditional aluminum. It also relies to a greater degree than other jets on electricity to run the plane’s systems, putting a spotlight on the lithium-ion batteries.
A JAL Dreamliner suffered a battery fire while parked at the Boston airport on Jan. 7, 2013. Nine days later, an ANA 787 pilot reported smoke while in flight over Japan, and inspections afterward found that the battery showed signs of charring.
No cause for the failures was ever determined because the battery cells were too badly damaged. GS Yuasa Corp., based in Kyoto, Japan, manufactures the batteries.
The battery-maker’s shares dropped 0.7 percent to 582 yen in Tokyo today, paring their gain in the past year to 73 percent. Japan Airlines gained 1.3 percent to 5,300 yen and ANA 0.9 percent to 225 yen.
Boeing’s battery fixes were designed to head off every possible way the batteries can fail, FAA Administrator Michael Huerta told Congress in February.
Japan Airlines will send the troubled battery to GS Yuasa today for further examination, Takaramoto said. The carrier has a fleet of 13 Dreamliners and 12 are working properly, he said.
ANA has 24 Dreamliners on its fleet and 23 are working fine, the carrier’s spokesman Ryosei Nomura said in a phone interview today. The airline has a “high degree of confidence” in the 787 battery fixes, Nomura said.
GS Yuasa, which was at the center of investigations last year, declined to comment on the matter, according to spokesman Tatsutoshi Kakishima.
Changes in the units included new components to minimize potential of a short circuit, insulation between cells to halt the spread of fire, and a new heat-resistant case and venting system. The battery enclosure was intended to ensure that fire can’t develop inside, while the voltage range of the batteries was also limited.
This week’s incident “provides another set of data that ultimately may help us find the root cause of this problem,” Tecop’s Weber said in a phone interview.