Boeing temporary battery fix tipped for Dreamliner
5:30 AM Friday Feb 22, 2013
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Boeing has developed a plan that it intends to propose to federal regulators to temporarily fix problems with the 787 Dreamliner's batteries that have kept the planes on the ground for more than a month, a congressional official said yesterday. Boeing Commercial Airplanes chief executive Ray Conner is expected to present the plan to Michael Huerta, head of the Federal Aviation Administration, tomorrow, the official said.
Marc Birtel of Boeing said it wouldn't talk in advance about meetings with federal officials. "Everyone is working to get to the answer as quickly as possible, and good progress is being made."
The FAA and overseas aviation authorities grounded all 50 of the planes flying worldwide after a lithium ion battery caught fire on a plane in Boston and a smoking battery led to an emergency landing by one in Japan.
The 787 is Boeing's newest and most advanced plane. It was meant to exemplify the future of commercial aviation, but the groundings have been a public black eye and financial drain for Boeing, which vies with Airbus for the spot as the world's largest commercial aircraft maker.
The plane is also the first airliner to make extensive use of lithium ion batteries to help power its electrical systems.
Lithium ion batteries weigh less, charge faster and hold more energy than other batteries of comparable size. But they are also more susceptible to short-circuiting that can cause fires if they are damaged, have manufacturing flaws, are exposed to too much heat or are overcharged.
The National Transportation Safety Board is investigating the battery fire in a Japan Airlines 787 discovered shortly after the plane landed at Boston's Logan International Airport last month.
Japanese authorities are investigating a battery failure in an All Nippon Airways 787 that made an emergency landing nine days after the fire.
Investigators have said the batteries experienced short-circuiting and thermal runaway, a chemical reaction that causes progressively hotter temperatures, but they haven't found the root cause of the incidents.
Japan's Transport Ministry says its investigation has exposed a new problem - the aircraft's auxiliary power unit, which contains a lithium ion battery, was improperly connected to the main battery that overheated.
NTSB investigators found the Boston fire started with multiple short-circuits in one of the battery's eight cells. That created a thermal runaway, which spread the short-circuiting to the rest of the cells and caused the fire.
The board's findings are at odds with Boeing's initial battery testing before FAA's safety certification of the plane, which found any short-circuiting could be contained within a single cell, preventing thermal runaway and fire from spreading.
Among the measures being discussed to make the batteries safe enough to return the 787 to the skies are adding more ceramic spacers between battery cells to contain any short-circuiting and fire within that cell. That would be in line with Boeing's initial test results.
More ceramic spacers would make the battery larger, which would require a bigger box to contain the battery cells. A more robust box lined with material to prevent any fire from spreading is also under discussion.
"What Boeing is trying to do is fix the battery so [its initial testing] assumption is now valid," said Jon Hansman, a Massachusetts Institute of Technology aeronautics professor and one of the FAA's Research and Development Advisory Committee.
"So if you can fix this part, the rest should be okay," he said.
Imperial Capital analyst Ken Herbert said last week the grounding could cost Boeing US$25 million ($29.95 million) a month in direct costs, with the total cost exceeding US$1 billion, including spending to fix it and expenses for delayed deliveries.
Boeing is still building five 787s each month, and has said it still wants to double that by the end of the year. It had orders for 800 before they were grounded.
It would take more than two months for Boeing to back away from its speed-up plan, UBS analyst David Strauss said.
Eight airlines in seven countries have 787s in their fleets.
Air New Zealand has 10 787-9s due for delivery next year.The grounding has been the most disruptive for Japan's All Nippon Airways, which has 17 of the planes.