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Investigators Identity Origin of Boeing 787 Battery Fire

Federal safety officials said they have identified the origin of the battery fire on a Boeing 787 Dreamliner last month, reports CNN.

Boeing had estimated a “smoke” event would occur “less than once in 10 million flight hours” with the Dreamliner’s novel lithium-ion batteries, National Transportation Safety Board chairwoman Deborah Hersman said. But after fewer than 100,000 hours of actual flight, two batteries failed, one culminating in a fire.

Further, Boeing’s indications that heat damage in one battery cell would not harm adjacent cells proved false, Hersman said.

“The assumptions used to certify the battery must be reconsidered,” Hersman said.
Hersman’s statements cast doubt not only on the safety of the battery technology, but on the government’s certification process for approving technology. It also appeared to dispel any hopes for a quick resolution to the problem, which has grounded all 50 Dreamliner aircraft globally since Jan. 16.

The NTSB plans to release an interim report of its findings within 30 days. The Federal Aviation Administration — the ultimate arbiter of when the plane can resume flying — has declined to predict when the 787 will return to the sky.

Hersman said the flight data recorder in the Boston incident showed the battery underwent an unexplained drop in voltage from 32 volts to 28 immediately before the incident, as the plane was being serviced on the tarmac. The voltage drop was consistent with the charge of a single cell on the eight-cell battery, she said.

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