WASHINGTON — Boeing has developed a plan that it intends to propose to federal regulators to temporarily fix problems with the 787 Dreamliner’s batteries that have kept the planes on the ground for more than a month, a congressional official told the Associated Press on Wednesday.
Boeing Commercial Airplanes chief executive Ray Conner is expected to present the plan to Michael Huerta, head of the Federal Aviation Administration, in a meeting on Friday, the official said. The official spoke on condition of anonymity because he wasn’t authorized to speak publicly.
Boeing Co. spokesman Marc Birtel said the company doesn’t talk in advance about meetings with federal officials.
‘‘Everyone is working to get to the answer as quickly as possible, and good progress is being made,’’ Birtel said.
The FAA and overseas aviation authorities grounded all 50 of the planes in service worldwide after a lithium-ion battery caught fire on a plane parked in Boston and a smoking battery led to an emergency landing by another plane in Japan. The 787 is Boeing’s newest and most technologically advanced plane. It was supposed to exemplify the future of commercial aviation, but the groundings have been a major public black eye and financial drain for Boeing, which vies with Airbus for the position as the world’s largest commercial aircraft maker.
The plane is also the first airliner to make extensive use of lithium-ion batteries to help power its electrical systems. Lithium-ion batteries weigh less, charge faster, and hold more energy than other batteries of comparable size. But they are also more susceptible to short-circuiting that can cause fires if they are damaged, have manufacturing flaws, are exposed to excessive heat, or are overcharged.
The National Transportation Safety Board is investigating the battery fire in a Japan Airlines 787 that was discovered shortly after the plane landed at Boston’s Logan International Airport on Jan. 7. Japanese authorities are investigating a battery failure in an All Nippon Airways 787 that made an emergency landing nine days after the fire. Investigators have said the batteries experienced short-circuiting and thermal runaway, a chemical reaction that causes progressively hotter temperatures, but they haven’t found the root cause of the incidents.
Japan’s Transport Ministry said Wednesday its investigation has uncovered a new problem: The aircraft’s auxiliary power unit, which contains a lithium-ion battery, was improperly connected to the main battery that overheated.
NTSB investigators found the Boston fire started with multiple short-circuits in one of the battery’s eight cells. That created the uncontrolled chemical reaction known as thermal runaway. That spread the short-circuiting to the rest of the cells and caused the fire.
The board’s findings are at odds with Boeing’s initial battery testing before FAA’s safety certification of the plane, which concluded that any short-circuiting could be contained within a single cell.
Among the measures being discussed to make the batteries safe enough to return the 787 to the skies are adding more ceramic spacers between battery cells to contain any short-circuiting and fire within that cell.