MELISSA BLOCK, HOST:
And as we continue to cover the events in the Boston area, we want to also talk about one other story, Boeing 787. The jet known as the Dreamliner will be back in the air soon. This afternoon, the FAA approved Boeing's redesign of the plane's battery system. Fifty 787s have been grounded for the last three months following two serious battery failures, one which led to a fire.
NPR's Wendy Kaufman has been following the story, and she joins us now. And Wendy, Boeing is getting a green light, so what makes government regulators confident that this fix will work?
WENDY KAUFMAN, BYLINE: Well, Melissa, I think the short answer is, there's been a lot of analysis and a lot of testing. So before Boeing redesigned this battery, it assembled a team of experts, including a lot of people from outside the company, to assess all the ways - and there are a lot of them - in which these batteries could fail, and then they came up with ways to address all of them.
After the redesign, the company spent 100,000 hours developing test plans, building test rigs, conducting tests, and analyzing the results. The FAA says, for its part, that its team of certification specialists observed those tests and devoted weeks to reviewing the detailed analysis, and they've come away believing that Boeing will ensure safety with its new battery plan.
BLOCK: So what does that mean? What changes did Boeing make?
KAUFMAN: They think of it as a multi-pronged approach. It's sort of a comprehensive solution. So first, the individual battery cells will be better insulated, so that a problem in one cell couldn't spread to another. Now - then, the charging system has been redesigned so that the amount of current that can be fed into the battery will be reduced. Then there's a fireproof, stainless-steel box that will house the battery. Excessive gasses will now be vented outside the airplane, and there'll be additional monitoring of the battery.
BLOCK: OK. Well, Wendy, I said these Dreamliners are going to be back in the air soon. How soon is soon?
KAUFMAN: Pretty soon. New batteries are being sent to the airlines. Boeing has created these so-called retrofit kits. It's dispatching 10 fix-it teams - about 300 people, in all - to help do the work. Each plane should take about five days to retrofit. Then there'll be some additional testing and retraining by the airlines. And then, after nearly four months, the 787 should be able to return to the skies.
BLOCK: OK. Wendy, thanks so much.
KAUFMAN: Thanks, Melissa.
BLOCK: That's NPR's Wendy Kaufman, speaking with us from Seattle. Transcript provided by NPR, Copyright NPR.