The Federal Aviation Administration issued a safety alert Sunday recommending that airlines inspect door plugs on Boeing 737-900ER jets and ensure they are properly secured, as it investigates the cause of a mid-flight door plug blowout on an Alaska Airlines jet earlier this month.
In this National Transportation Safety Board (NTSB) handout, plastic covers the exterior of the ... [+]
In a notice, the FAA asked airlines to inspect four locations where a bolt is used to “secure the door to the airframe” of a Boeing 737-900ER jet as soon as possible.
The agency said it is continuing its investigation into data about the door plug and will “will determine additional action as necessary.”
The 737-900ER is an older model of Boeing's widely used single-aisle aircraft and different from the grounded 737 MAX 9 involved in the Alaska Airlines door plug blowout incident.
The FAA, however, noted that the 737-900ER’s door plugs “have an identical door plug design” to the MAX 9.
Door plugs—like the one that blew off the Alaska Airlines jet—are used in place of an optional emergency exit door in planes with less dense seating arrangements.