Boeing starts costly repairs to Dreamliner batteries An All Nippon Airways Boeing 787 Dreamliner at Haneda airport, in Tokyo. Photograph: Toru Hanai/Reuters Boeing has begun repairs to its troubled 787 Dreamliners to fix the battery problem that grounded the entire fleet of 50 planes and suspended deliveries. "We have put in extensive resources to make sure we understood the potential causes of the battery failure and to make sure they were addressed," said William Loftis, vice-president of Boeing's 787 programme. We have come up with a very comprehensive solution set. I look forward to flying it. I look forward to putting my family on the airplane and enjoying it. A team of 300 Boeing engineers, mechanics and advisers has been dispatched to change the batteries in Dreamliners in nine countries. Work started on Monday in Japan, where All Nippon Airways and Japan Airlines are some of the biggest customers of the 787. Loftis said Boeing, which is the world's largest plane-maker, would resume deliveries of the Dreamliner "within weeks." He did not believe the problem would harm future sales. Airlines must await permission from aviation authorities before commercial flights can resume. Last week, the US Federal Aviation Authority signalled its approval of Boeing's redesign of the battery system. 787 Dreamliner battery changes Boeing had made 12 changes to the battery, including encasing it in a stainless steel box - a job that took five days for each plane, and could be done at a "fairly small" cost, Loftis said. The lithium-ion batteries, which were chosen for their lightness and energy efficiency, power the plane's electric braking and navigation lights. The redesign means that in the event of a problem, vapours from the battery box would be expelled from the plane, Boeing said. Analysts estimate that the saga has cost Boeing $600m (£394m), a figure that is likely to escalate because several airlines are demanding compensation. Boeing refused to discuss compensation or the cost of the battery failures, citing a news blackout before the publication of quarterly earnings on Wednesday. "We fully understand and regret the impact that this event has cost out customers and their customers," Loftis said.