(NewsNation) — A safety alert issued by the Federal Aviation Administration Sunday recommends airlines visually inspect door plugs on the Boeing 737-900ER, after an incident where one blew off an Alaska Airlines plane earlier this month.
“The Federal Aviation Administration (FAA) continues to evaluate data involving the mid-cabin door plug and will determine additional action as necessary,” the alert said.
Door plugs are panels that seal holes left for extra doors when the number of seats is not enough to trigger a requirement for more emergency-evacuation exits, according to the Associated Press.
The Boeing 737-900ER mid-exit door plugs have an “identical” design to the 737-9 MAX, which suffered an inflight blowout on Jan. 5 over Oregon, according to the alert. No serious injuries were reported.
Since Jan. 5, the FAA said, it has been collecting data on what happened, as has the National Transportation Safety Board. The agency also grounded the 737 Max-9 fleet.
“Some operators have conducted additional inspections on the 737-900ER mid-exit door plugs and have noted findings with bolts during the maintenance inspections,” the alert said.
Airlines should look at the four places where a bolt, nut and pin secures the door plug to the plane “as soon as possible,'” it cautioned.
Alaska and United Airlines tell NewsNation they’ve already begun inspections suggested by the FAA.
“We fully support the FAA and our customers in this action,” a Boeing spokesperson said in an email to NewsNation partner The Hill.
The Associated Press contributed to this report.
