Seattle,
Feb 1: In 2007, U.S. regulators cleared Boeing's use of a highly
flammable battery in the 787 Dreamliner, deciding it was safe to let the
lithium-ion battery burn out if it caught fire mid-air as long as the flames
were contained, and smoke and fumes vented properly, according to documents
reviewed.
Fire risk on planes has always been a major concern, especially
given the amount of fuel they carry and the heat generated by jet engines. U.S.
aviation standards require planes to have numerous on-board fire suppression
systems.
But through a review of government documents and interviews with
aviation and battery experts, media found that the U.S. Federal Aviation
Administration granted the Dreamliner special conditions and said its
contain-and-vent system was sufficient to control the build-up of explosive or
toxic gases, except in situations considered "extremely remote."
The
FAA's 2007 decision is now coming under scrutiny after the lithium-ion batteries
in two 787 planes failed within days of each other, sparking a fire in one case
in Boston, and generating warnings and an acrid smell that prompted the pilots
of the second plane to make an emergency landing in Japan.
A key U.S.
Senate committee plans to hold a hearing in the coming weeks to examine aviation
safety oversight and the FAA's certification of the 787, an aide to the Senate
Commerce, Science and Transportation Committee said.
The FAA has grounded
the Dreamliner in the U.S. pending an investigation, and other aviation
regulators around the world immediately followed, stopping use of all 50 planes
in service, each of which can carry about 250 passengers.
The National
Transportation Safety Board is conducting the U.S. probe, with help from Boeing,
the battery maker, GS Yuasa Corp of Japan, and the FAA.
The review has
broad implications for other aircraft makers, including EADS unit Airbus, which
also had to meet special conditions set by the FAA to use lithium-ion batteries
on the A380 - a superjumbo jet that carries about 550 passengers.
A
spokesperson for the FAA defended the 2007 approval, saying, "the whole aviation
system is designed so that if a worst case happens, there are systems in place
to prevent that from interfering with other systems on the plane."
Boeing
said the 787's battery system has four layers of protection to prevent the
battery from overcharging, making a fire extremely unlikely. The company said it
was confident the battery could safely burn out in air because of a robust
system for containing a fire and venting smoke and fumes.
The batteries
were chosen "after a careful review of available alternatives because they best
met the performance and design objectives of the 787," Boeing spokesman Marc
Birtel said. "Based on everything we know at this point, we have not changed our
evaluation."
The cause of the two 787 battery failures is not yet known
and investigators are still determining how the contain-and-vent systems
performed. But the incidents have revived a decades-old debate on the safety of
lithium-ion batteries and raised questions over whether the FAA should have
consented to their use in the 787.
Congressman Rick Larsen, who was named
ranking member of the House Aviation Subcommittee, said it was appropriate for
the FAA to impose special conditions for the 787, the world's first carbon
composite aircraft, but a review of the approval "may be something we could look
at in light of the current problems."
The FAA spokesperson said the
agency may add new requirements for the batteries upon completion of the NTSB
probe, but declined to elaborate.
Depending on the outcome of the review,
Boeing could face steep costs, ranging from compensating airlines for lost use
of planes to a possible major redesign and re-certification of the battery or
electrical system, industry experts say.
Lithium-ion batteries are
lightweight, recharge quickly and can hold more power than conventional cells.
But they have a history of safety concerns, leading some battery experts to
question their use in any consumer product.
In the FAA's 2007 review, it
said lithium-ion batteries were "significantly more susceptible" to fires than
other types and added that those fires are tough to put out.
"Metallic
lithium can ignite, resulting in a self-sustaining fire or explosion," the FAA
said in granting approval.
FAA rules do not cover lithium batteries, so
the agency in 2007 set nine "special conditions" Boeing had to meet to ensure
their safety. A year earlier, the FAA had set similar conditions for Airbus.
Special conditions are commonly used to cover new technology for which rules
have not yet been written.
In both cases, the Air Line Pilots Association
International, the world's largest pilot union, said airplane fire is so
dangerous that the FAA should require cabin crew to have fire extinguishers and
training to put out a lithium-ion battery fire. "A fire from these devices, in
any situation, is unacceptable," the union said, during the 787 approval
process.
The FAA said it chose not to require special fire extinguishers
and training because of the four redundant systems already in the Boeing system
to prevent the battery from catching fire.
The ALPA said it is monitoring
the investigation into the 787 battery incidents, but declined to comment while
the probe is going on.
"It goes back to why this was approved in the
first place," said Hidetake Sakuma, an aviation safety consultant and a former
safety manager at Japan Airlines Co Ltd.
"Of course there were people
asking whether this was really safe, but they (the FAA) approved it and the
Japanese airlines never questioned it."
Japanese airlines operate nearly
half of the 787s in service.
Passengers on the Japan flight reported an
odor like burning plastic soon after takeoff. All Nippon Airways Co Ltd Vice
President Osamu Shinobe said in addition to a battery alert in the cockpit,
"there was an odd smell detected in the cockpit and cabin."
The NTSB
declined to comment, citing the ongoing probe. The Japan Transportation Safety
Board, which is leading that investigation, and the NTSB so far describe it as a
"battery incident," not a fire.
A photograph of the battery retrieved
from the flight showed a blackened, melted interior with fused wires, a deformed
lid and scorched casing.
A GS Yuasa spokesman said the company is
cooperating with the investigation, but declined to comment on the
details.
Boeing has not commented specifically on the battery failure in
this incident. In the case of the Boston plane, Boeing said smoke got into the
cabin because the 787 was on the ground without cabin pressure to redirect
airflow.
Some experts cautioned against a rush to judgment about
lithium-ion battery technology, saying the key was to understand failure rates
and design a safe system.
"Everyone knew these dangers, but after it was
designed, there were multiple tests and that's why it's in the final plane,"
said Yoshitomo Aoki, a Japanese aviation commentator. "It wouldn't have been
approved if it wasn't safe."
Airbus plans to use lithium-ion batteries in
its forthcoming A350 jet, its answer to the 787. That plane will use a different
architecture that puts less stress on batteries, while expelling unwanted gases
safely, Airbus says.
The NTSB widened its probe to include the Tucson,
Arizona-based company that makes the charger for the batteries, Securaplane
Technologies, a unit of Britain's Meggitt Plc. Securaplane said it is
cooperating with the investigation.
"In no way would a fire like this
lead me to say you should never have a lithium-ion battery on an airplane.
That's just the wrong way to go," said Daniel Doughty, who helped write testing
standards for electrical cars and worked on battery technology during 27 years
at Sandia National Laboratory, a federally funded research center owned by
Lockheed Martin Corp.
But Doughty and others said the FAA's earlier
decisions deserved scrutiny.
"It's fair to ask about the approval
process," Doughty said. "There needs to be some explanation and defense of
whatever they did."
Ends
SA/EN
Home »
» Insight: Boeing 787 battery woes put FAA approval under scrutiny
Insight: Boeing 787 battery woes put FAA approval under scrutiny
Subscribe to:
Post Comments (Atom)
0 comments:
Post a Comment