Boeing is making "steady progress" on the path to certifying a software update to the 737 Max and has made the final test flight before certification, its chief executive said on Wednesday.
"We are making steady progress toward certification," Boeing CEO Dennis Muilenburg said in a video on his Twitter account.
"Yesterday we completed the official engineering flight test with the updated software with our technical and engineering leaders on board the airplane. That was the final test flight prior to the certification flight."
Boeing is updating the software controlling an anti-stall system that has been linked to deadly crashes in Indonesia and Ethiopia. The 737 Max remains grounded around the world pending regulatory approval to resume flying.