Alaska Airlines and United Airlines said on Monday that they have found loose parts on their 737 Max 9 aircraft since they started inspecting some of their grounded Boeing jets, bringing additional scrutiny to the component called a door plug that blew off a Max 9 aircraft last week.
About 170 planes were removed from service after the incident involving an Alaska Airlines jet that had just taken off from Portland, Ore., on Friday night. United and Alaska are the two major U.S. carriers that fly Boeing jets with this particular configuration of door plugs.
