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 The incident raised fresh concerns about the 787's safety and
reliability almost exactly one year after the global Dreamliner
fleet was grounded by regulators following the overheating of two
such batteries, although Boeing said design changes made as a result
had worked as planned.
Boeing Co <BA.N> 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.
"The issue occurred during scheduled maintenance activities with no
passengers on board," said Boeing. "The improvements made to the 787
battery system last year appear to have worked as designed."
Boeing shares closed down 0.5 percent at $140.01 on the New York
Stock Exchange.
The incident, which was disclosed by Japan Airlines early on
Wednesday local time, came nearly a year to the day after Japan
Airlines and All Nippon Airways grounded their 787 fleets after two
787 batteries overheated on two different planes in less than two
weeks.
Global regulators grounded the worldwide fleet on January 16, 2013.
The 787s remained grounded for more than three months while Boeing
redesigned the battery, charger and containment system to ensure
battery fires would not put the airplane at risk. The cause of the
battery problems has not been determined.
United Airlines <UAL.N>, the only U.S. carrier that uses the 787,
was conducting precautionary checks on its 787s, according to a
person familiar with the matter who asked not to be named because
they were not authorized to speak publicly.
United declined to comment on the inspections, saying only that "Our
787s are operating normally and we have not experienced any issues
with our batteries."
Japan Airlines said maintenance engineers who were in the cockpit
saw white smoke outside the plane. When they went outside the
aircraft the smoke had dispersed.
On returning to the cockpit, the engineers found warning lights
indicating possible faults with the main battery and charger. When
they checked the battery, located inside a steel containment box,
they found one of eight cells was leaking a liquid.
Japan Airlines said that inside the containment box inspectors found
a pressure relief valve had opened in one of the battery's eight
cells. The valve in the battery case is designed to open when
pressure rises inside a cell, Japan Airlines said.
The problem did not appear to have propagated to other cells in the
battery, said a person familiar with the matter, who was not
authorized to speak publicly.
The liquid that leaked out also did not appear to breach the
containment box, and it appears that any fumes vented through a port
that is part of the containment system, a sign the system likely
worked properly, this person said.
The plane, due to depart from Narita for Bangkok, was taken out of
service, and the 158 passengers due to board the plane were put on a
separate 787, JAL said.
PLAGUED WITH PROBLEMS
The 787 Dreamliner is Boeing's state-of-the-art plane, built with
carbon-fiber composite materials and a powerful electrical system to
reduce weight and improve the jet's fuel efficiency.
But the 250-seat jetliner, which costs about $212 million at list
prices, has been plagued with problems. It was more than three years
late in entering service, due to issues with parts fabrication by
suppliers around the world. Since entering service, it has had
issues with brakes, fuel lines, electrical panels and hydraulics,
and other systems.
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The overheating of the jet's lithium-ion batteries raised serious
concerns last year, prompting world-wide grounding of the fleet
after a fire on a Japan Airlines plane in Boston and a second
battery that overheated on an All Nippon Airways flight in Japan
less than two weeks later.
In July, after the 787 was cleared to return to service, an
Ethiopian Airlines jet caught fire at London's Heathrow Airport,
scorching the fuselage. The cause of the fire was never firmly
established, but UK investigators traced the probable cause to
faulty wiring of a lithium battery in an emergency beacon located in
the ceiling near the tail of the plane.
EXPERTS WEIGH IN
Aerospace experts said the latest Japan Airlines incident was
troubling, but were cautious about drawing broader conclusions.
Richard Aboulafia, an aerospace analyst at Teal Group in Fairfax,
Virginia, said the incident raised two questions: whether the new
system that contains the problem had worked, and whether the root
cause of the battery problems will ultimately be discovered.
"The real issue with containing the problem, rather than getting to
the root cause of the problem, concerns economics," Aboulafia said.
"Incidents can be successfully contained, but if you continue to see
incidents like these, you've got a mounting bill from taking jets
offline, and repairing their battery systems. You've got an image
problem, too."
Hans Weber, a former FAA adviser and president of TECOP
International, an aerospace technology consulting firm, said the
incident might provide more clues about the cause of the problem,
such as overcharging.
He said it appeared the containment system worked. "It limited the
problem to one faulty cell. It contained the problem and vented the
fumes outside the airplane, as designed," he said, basing his
comments on Japan Airlines' initial statements about the incident.
The U.S. National Transportation Safety Board said it is aware of
the incident and is gathering information. Separately, the NTSB is
still investigating the battery fire that occurred on the Japan
Airlines 787 in Boston a year ago, and said last week it is due to
complete that investigation in March. The agency did not say whether
the latest battery incident would affect the timing of the Boston
investigation.
The U.S. Federal Aviation Administration said it was working with
Boeing and the Civil Aviation Bureau of Japan to investigate the
battery malfunction.
The agency certified Boeing's revamped 787 battery system as safe
last year after the Dreamliner fleet was grounded for more than
three months. The agency also launched a review of the design,
manufacture and assembly of the 787 in January last year and said
its report would be released last summer, but it has so far not
released the report and has not responded to questions about when
that review would be finished.
(Reporting by Tim Kelly and Kentaro
Sugiyama in Tokyo, Alwyn Scott in Seattle and Nivedita Bhattacharjee
in Chicago; editing by Steve Orlofsky, Jeffrey Benkoe and Bernard
Orr)
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