By Chandni Shah and Devika Madhusudhanan Nair
(Reuters) -Boeing has started certification flight testing of its long-delayed 777-9 with U.S. aviation regulators onboard, the U.S. planemaker said in an emailed statement.
The company said it conducted its first flight on Friday night after receiving Type Inspection Authorization (TIA).
The development is a boost for Boeing (NYSE:BA), which has been grappling with production and legal issues since a Jan. 5 mid-air panel blowout on a 737 MAX plane.
The news was first reported by Air Current.
The U.S. Federal Aviation Administration (FAA) while declining to comment on specific certification projects, said "Generally, this kind of thorough process takes many months."
The 777-9 is part of the 777X project to upgrade the 777 wide-body jet. The project has been in development since 2013 but has faced multiple hold-ups, including certification delays.
Type inspection authorization is typically associated with the start of the certification process, made after the FAA has examined technical data. The milestone allows FAA pilots to participate in flight testing needed to certify the plane for normal operation.
The chairman of Emirates, the plane's biggest customer, said in May he did not expect the certification before the first quarter of 2025.
Boeing has said that the 777-9 test fleet will undergo the most thorough commercial flight test effort the planemaker has ever undertaken.