Door Plug Inspections Spread To NG900ERs


The FAA has told airlines operating Boeing 737-900ER airliners to check the installation of door plugs as they are the same design as those on the 737 MAX 9. The agency issued a safety alert, which is a recommendation that carriers inspect the planes. It does not ground the type as an earlier order for the MAX 9 did. “As an added layer of safety, the Federal Aviation Administration is recommending that operators of Boeing 737-900ER aircraft visually inspect mid-exit door plugs to ensure the door is properly secured,” the agency said in a statement on Sunday.

Not all of the 900 ERs have the door plugs, which are installed when there aren’t enough seats in the aircraft to warrant an additional emergency exit. Alaska, United and Delta all have 900ERs, the largest model in the NG line of 737s, which went out of production in 2019 in favor of the MAX line. Only a visual inspection is required and no schedule disruptions are anticipated. Meanwhile, 171 MAX 9s with door plugs remain grounded and there is no timeline on when they will return to service after a Jan. 5 incident in which a door plug separated from an Alaska Airlines MAX 9 shortly after takeoff from Portland.

Russ Niles
Russ Niles is Editor-in-Chief of AVweb. He has been a pilot for 30 years and joined AVweb 22 years ago. He and his wife Marni live in southern British Columbia where they also operate a small winery.


  1. Why door plugs rather than the regular exit door if if that door is not mandated by the seating?

    Cost? Obviously the plug costs less.
    Weight? I am sure the plug weights less.
    Expense of inspections/maintenance required for an actual exit door with slide?

    Is the choice of a door or plug part of the design or is it specified by the airline at the time of interior assembly and delivery.

    I have not seen any of these questions addressed.

    • Even if the extra door wasn’t mandated, even if it costs more, even if it weighs more, it would have made it a safer aircraft. Of course neither Boeing or its customers thought that more important than the cost.

    • > I have not seen any of these questions addressed.
      I can help you with that!

      Look on YouTube for “The Boeing 737 Technical Channel”. Look for a video named, “737 Mid-Cabin Emergency Exit Doors”, dated 6 Jan 2024. It describes how the choice of the door or plug design is based on the airline’s intentions for number of seats in the aircraft, and lists the options.

      This same channel has two later videos on the 737 door plug option, with updated information about the plugs, but these videos do not directly address your questions.

      I am not giving links to the videos, to avoid this comment falling into the moderation queue, and perhaps being delayed. But they are easy to find on YouTube.

      • Thank You

        I did watch the “plug option” video and it was informative.

        The design of the plug and its holding mechanism seems very robust.

        With the aircraft only in service a couple of months stress fatigue of the holding mechanism seems unlikely.

        Will be interesting to see the NTSB report if it is made public within peoples attention span.

    • The aircraft is certified with both the door and the plug.

      The door is required for when higher density seating arrangements are used. It is not just the weight of the door but most likely slide mechanism. The inflatable slide and door require regular inspection and service . Hauling the door around the sky also requires more fuel due to its added weight.

      The continued grounding of the aircraft MIGHT indicate that the problem is not just the failure to properly the plug.

  2. Choosing cost over safety will its not play well in litigation, as it should not. One wonders if Boeing or its customers consulted their counsel or insurers in so deciding.