Batteries similar to those at the center of the recent problems with Boeing Co.'s 787 Dreamliner have raised growing concerns with air-safety regulators in recent years.
The U.S. Federal Aviation Administration ordered a halt to Dreamliner flights on Wednesday after two major battery malfunctions aboard the aircraft, and regulators world-wide followed the FAA's lead, effectively grounding Boeing's flagship jet.
Until now, the biggest worry about lithium-ion batteries centered on the kind used in electronics products, such as laptop computers and cellphones, that were shipped in bulk as air cargo or stowed in passengers' carry-on baggage. The Dreamliner is the first passenger plane to use big lithium batteries as a backup power source.
It remains unclear whether the Dreamliner's batteries, which are produced by Japanese battery maker GS Yuasa Co., caused the problems on two Dreamliners operated by All Nippon Airways Co. and Japan Airlines, respectively. Other factors, such as their wiring or installation, could have contributed to the incidents, industry officials say.
Whatever the cause, the power cells posed a risk because they are highly flammable under certain conditions. Lithium batteries are vulnerable to overheating if overcharged, or if discharged too rapidly, and overheated or damaged batteries can catch fire. They burn at extremely high temperatures, may emit flammable vapors, flames or sparks, and can even explode.
The danger is related to what makes the batteries popular: They can store large amounts of energy. They combine light weight and compact size with the ability to charge up and discharge quickly.
Over the past decade, aviation regulators have recorded dozens of incidents in which lithium batteries in consumer products have overheated or caught fire on planes or at airports. Stricter international safety rules kicked in this year to tackle the hazards of shipping such batteries by air.
Large shipments of the power cells are suspected of having played a role in the fatal crashes of two jumbo-jet cargo planes in 2010 and 2011 and the destruction of a smaller freighter in 2006, according to safety officials.
Despite the concerns about lithium batteries, they are being used more widely in aircraft. The U.S. military's new F-35 Lightning II Joint Strike Fighter jet uses lithium-ion batteries produced by a unit of French battery maker Saft Groupe SA. No safety incidents with the units have been publicly reported.
A spokesman for Lockheed Martin Corp., which builds the fighter, said in a statement that its batteries aren't from GS Yuasa, and that "we expect no impact [on the Joint Strike Fighter] program."
Europe aircraft maker Airbus, a unit of European Aeronautic Defense & Space Co., uses small lithium batteries for emergency power on its two-deck A380 super-jumbo, which entered service in 2007.
Airbus plans to use bigger lithium batteries on its new A350 model, now in development, but those cells still will be smaller than those aboard the Dreamliner. Saft will supply the A350 batteries, Airbus said.
The Dreamliner is an unusual airplane because it relies on electric power for most of its functions.
Previous airliners from Boeing, Airbus and other manufacturers have used a combination of electrical and mechanical power drawn from a plane's engines.
The new Airbus A350 will use roughly one-third the electric power of the Dreamliner, Airbus officials said Thursday. The plane also uses two batteries in parallel where Boeing uses one, reducing the power that each one stores and discharges, Airbus officials said.
"We don't need as much power, and it's a different architecture on the A350," said Tom Williams, Airbus's executive vice president for programs. He declined to comment on how the 787 incidents might influence the A350's battery design. "We need to wait and see what the investigation tells us," he said.
As concerns about the batteries have increased, the FAA has conducted extensive testing of their performance. In at least one test, the batteries burned hot enough to melt test equipment, according to a person familiar with the results.
In another set of tests last year, the FAA caused lithium batteries in a laptop computer to ignite in the cockpit of a Boeing 737 jet. Pilots increasingly use laptop and tablet computers as replacements for the heavy maps and manuals they have long lugged around.
The test focused more on the smoke hazard from a fire than the damage caused by flames. To disperse the smoke, the testers boosted ventilation in the cockpit, replacing its air entirely once every minute, according to an FAA report of the test.
Nevertheless, the testing showed that a standard lithium laptop battery, which is much smaller than the models on the Dreamliner, "could pose a significant smoke hazard" in the cockpit, the report said. In one test, the smoke was dense enough to cause a "severe lack of visibility."
Friday, January 18, 2013
AIRCRAFT - Boeing 787 Like Lithium-Ion Batteries a Long Concern
"Batteries Like Those on Dreamliner Raised Concerns" by DANIEL MICHAELS, Wall Street Journal 1/17/2013
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