Boeing Co. completed a final test flight for the 787 Dreamliner Friday after finishing ground trials of an upgraded battery system on the jet removed from commercial service in January.
“The purpose of the test is to demonstrate that the new system performs as intended during normal and non-normal flight conditions,” Marc Birtel, a Boeing spokesman, said by email.
The flight is the last certification test for the lithium-ion batteries before the new design is submitted for U.S. Federal Aviation Administration approval. The agency will assess whether the proposed fix is sufficient to let 787s fly again after batteries overheated on a Japan Airlines Co. plane in Boston and during an All Nippon Airways Co. flight in Japan.
Boeing said FAA officials were aboard the 787, a LOT Polish Airlines SA plane that has made three unrelated check flights with the new system since March 25.
U.S. Transportation Secretary Ray LaHood declined to say Friday when he will decide whether to end the grounding, which began with an FAA directive on Jan. 16 and was followed within hours by regulators around the world.
Boeing must convince regulators the Dreamliner and its battery upgrade are safe before flights can resume, LaHood said. The concept for the fix on which the FAA signed off in March “was a good plan,” and regulators are now waiting to see the results, he said.
“We want to get it right,” LaHood said. “We want to make sure that everything’s done correctly. We want to be able to assure the flying public that these planes are safe.”
Boeing’s ground tests included overheating the system to evaluate a stainless-steel enclosure designed to eliminate the possibility of fire and a tube that would vent any liquid or vapors outside the plane. The design also increases the spacing and insulation for the power cells to prevent the spread of any overheating and includes new circuitry for the battery chargers.