Updated January 20, 2013, 11:27 a.m. ET
By ANDY PASZTOR and JON OSTROWER
The Wall Street Journal
The
National Transportation Safety Board Sunday added a new twist to the
high-profile probes of electrical malfunctions aboard a pair of Boeing
Co.'s 787 airliners by disclosing that the battery that caught fire on a
parked Japan Airlines Co. jet earlier this month "did not exceed its
designed voltage."
Japanese investigators looking into the cause
of a second lithium-ion battery malfunction aboard an All Nippon Airways
Co. 787, which occurred a little more than a week later, have indicated
the battery in that incident may have been overcharged, leading to an
emergency landing after pilots noticed a burning smell. They also have
suggested similarities between the two incidents could help experts
quickly get to the bottom of what happened.
The safety board's
update, released early Sunday, suggests different circumstances may have
preceded the two incidents and that at least to some extent, the
investigations surprisingly may be headed in divergent directions.
If
that is the case, it may complicate efforts to determine the root cause
of the two incidents and potentially delay Boeing's effort to persuade
regulators to allow the planes back into service.
Both batteries
were heavily charred, according to previously released images. The
Federal Aviation Administration last week said both batteries leaked
electrolyte fluid and resulted in smoke damage to nearby portions of the
aircraft.
U.S. and Japanese safety experts have been working
together and sharing preliminary information, though their
investigations are being run separately. It is too early to draw
definitive conclusions, according to people familiar with both probes,
and FAA officials are waiting for more data and analysis before agreeing
on interim safeguards to allow 787 Dreamliners back in the air.
The
NTSB's latest release, while highlighting the breadth and depth of its
investigation, doesn't appear to resolve the most pressing questions.
The
safety board disclosed that a team of investigators, including industry
experts, are conducting detailed examinations of the internal structure
of the battery in the JAL incident, which caught fire while it was
being recharged on Jan. 7 at Boston's Logan International Airport
following a flight from Tokyo. Various high-tech scans of the battery,
and disassembly of a number of cells, appear intended to help
investigators determine whether some type of internal fault or
manufacturing defect prompted the battery to overheat and start the
fire.
As part of its expanding probe, the safety board also is
looking at external factors. On Sunday it said investigators already
have examined wiring, circuit boards and other battery-related
components removed from the aircraft. Investigators also intend to test
components that feed power into the battery, according to the update.
On
Tuesday, according to the NTSB, a group of safety experts will meet in
Arizona "to test and examine the battery charger," which is manufactured
there by Secureplane Technologies Inc., a unit of Meggitt PLC.
The
safety board took the unusual step of releasing an update to its 787
investigation just after midnight, during a three-day weekend including a
federal holiday. The world-wide grounding of Boeing 787s is now
stretching into its fifth day, as the company and U.S. and Japanese
investigators work to find the causes of the two incidents.
The
NTSB also said that certain parts removed from the JAL 787 have been
sent to Boeing for analysis and download of data at the company's
facilities, a step that could assist the Chicago plane maker in
developing potential interim safeguards needed to return the fleet to
service. Previously, Boeing officials expressed frustration that some
data gathered by government investigators hadn't yet been provided to
the company.
When the FAA last Wednesday ordered the 787 fleet in
the U.S. grounded, the emergency directive effectively put a halt to
all deliveries of new Dreamliners because Boeing is prohibited from
conducting test flights of yet-to-be-delivered 787s. Boeing formally
announced a moratorium on Dreamliner deliveries Friday.
Source: http://online.wsj.com
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