UBS analyst David Strauss estimated last month that the 787 will cost Boeing $6 billion this year. Besides the battery problems, the plane already costs more to build than it brings in from customers.
United has six Dreamliners, plus another 44 on order. American and Delta have also ordered 787s. Boeing has orders for more than 800 of the planes from airlines around the globe.
The 787 has two identical lithium-ion batteries, one of which is located toward the front of the plane and powers cockpit electrical systems, the other toward the rear and used to start an auxiliary power unit while the plane is on the ground, among other functions. It was the battery toward the rear that caught fire and gushed smoke on the plane in Boston, which had recently landed after an overseas flight. It was the other battery toward the front that failed on the plane in Japan.
Every item that is part of an airplane, down to its nuts and bolts, must be certified as safe before FAA approves that type of plane as safe for flight. The two events have raised questions about why the FAA and Boeing didn't uncover problems with the batteries before the FAA certified the plane as safe for flight in 2011. In recent years, the FAA has relied to a greater extent on designated employees of aircraft makers to conduct the safety testing necessary of certification. Some aviation safety experts have questioned whether FAA has the in-house expertise to oversee the safety of cutting-edge technologies that haven't been in planes before.
Lithium batteries are much more likely to experience uncontrolled high temperatures that can lead to fires if they are damaged, exposed to excessive heat, overcharged or have manufacturing flaws. Despite their safety risks, they are increasingly attractive to aircraft makers as a way to cut weight and thus improve fuel efficiency.
The National Transportation Safety Board is investigating the Boston battery fire and the process by which the FAA certified the 787's batteries were certified as safe. The board has scheduled a two-day hearing beginning Tuesday at which FAA and Boeing officials are slated to testify.
NTSB officials have said the Boston battery fire began with a short circuit in one of the battery's eight cells, leading to uncontrolled temperatures and short-circuits in the rest of the battery's cells. Firefighters who responded to the incident reported dense clouds of white smoke and two small flames on the outside of the box that contained the battery cells.
Associated Press writer Monika Scislowska in Warsaw, Poland, contributed to this report.
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