Boeing conducted a second 787 test flight related to the certification of its fix for the aircraft’s lithium ion batteries. The company said in a statement that it was the “final certification test for the new battery system.”

The Friday flight, operated with a production aircraft designated for LOT Polish Airlines, went west from Paine Field in Everett, Wash., to the Pacific coast line, flew south along the Washington state coast and then over the Oregon coast before turning around and returning to Paine Field, according to flight tracking service FlightAware. The flight lasted just under two hours.

The worldwide Dreamliner fleet has been grounded since Jan. 16 following the failure and overheating of lithium ion batteries on two in-service 787s within a 10-day period. Boeing is endeavoring to convince FAA that its fix for the battery system should enable the lifting of the grounding.

Boeing said it has now completed “the testing required by” FAA.

“The crew reported that the certification demonstration plan was straightforward and the flight was uneventful,” Boeing said following Friday’s flight, adding, “Boeing will now gather and analyze the data and submit the required materials to the FAA. We expect to deliver all of the materials to the FAA in the coming days. Once we deliver the materials we stand ready to reply to additional requests and continue in dialog with the FAA to ensure we have met all of their expectations.”