US aviation officials may allow Boeing's Dreamliner to fly again

Boeing's beleaguered 787 could be flying again within a week after federal officials approved a fix for its batteries, even though the root cause of a fire on one plane and smoke on another still is not known.

The Federal Aviation Administration said Friday it would send airlines instructions and publish a notice next week lifting the 3-month-old grounding order that day. Airlines will be able to begin flying the planes again as soon as the new systems are installed and they have approval from safety regulators in their own countries. Dreamliner flights could resume within a week, the agency told members of Congress.

Boeing is eager to get the planes flying. It has stationed 300 workers on 10 teams around the world to do the work, some of it beginning on Friday, 787 chief engineer Mike Sinnett said on a call with reporters. It will take about five days to install the revamped lithium-ion battery system on each plane, he said.

The FAA gave Boeing permission last month to test the revamped system, which includes additional insulation around each of the battery's eight cells to prevent a short circuit or fire in one of the cells from spreading to the others. The new system also includes enhanced venting of smoke and gas from inside the battery to outside the plane. A strengthened box to hold the battery is an effort to ensure that if a fire were to occur, it would not escape to the rest of the plane.

Boeing has completed 20 separate tests of the new system, FAA Administrator Michael Huerta told Congress earlier this week.

The system involved in the emergencies in January had been extensively tested, too.

"We always learn more as we dig deeper into things," Mr Sinnett said. "We have learned a lot about how to test batteries, and to be conservative" in testing.

Boeing had delivered 50 planes to eight airlines in seven countries when a fire erupted in a battery aboard a Japan Airlines 787 parked at Boston's Logan International Airport on January 7. Nine days later another incident forced an emergency landing in Japan by an All Nippon Airways 787. That prompted the FAA and other authorities to ground the entire fleet.

Boeing said new batteries and kits with the parts for the new battery systems have been shipped to Boeing supply centers around the world and are ready to be installed. The 787s will get the fix in approximately the order they were delivered, Boeing said.

The FAA's action directly affects the six 787s flown by United Airlines, the only US airline with the plane. But aviation authorities in other countries are expected to follow suit swiftly. Boeing deferred questions about approval in other countries to those aviation authorities.

* AP