(CNN) -- A flight labeled the "final" certification test of an improved battery system for the grounded Boeing 787 Dreamliner was "straightforward" and "uneventful," the airplane maker said Friday.
The test was an important one for Boeing, which has billions of dollars riding on the success of the new airliner. The U.S. Federal Aviation Administration and similar regulators worldwide grounded the Dreamliner in January after two battery-related fires damaged 787s in Boston and Japan. No one was hurt in the fires.
In March the FAA approved a Boeing certification plan to fix the 787's problematic lithium-ion battery system and prove the new design is safe. Friday's nearly two-hour flight was the final certification test of that plan.
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Boeing "will now gather and analyze the data and submit the required materials to the FAA," the company said in a news release. It said it expects the material to be delivered in a matter of days.
The flight left Paine Field in Everett, Washington, at 10:39 a.m. with a crew of 11, including two FAA representatives, Boeing said, and it returned at 12:28 p.m.
"The crew reported that the certification demonstration plan was straightforward and the flight was uneventful," Boeing's news release said. "The purpose of the flight was to demonstrate that the new battery system performs as intended during normal and non-normal flight conditions."
At the time the planes were grounded, 50 787s were flying worldwide. U.S. Department of Transportation Secretary Ray LaHood said in March the Dreamliner will not be allowed back in service until Boeing proves the new design is safe for passengers.