22-1-2024 (WASHINGTON) The United States Federal Aviation Administration (FAA) issued a recommendation on January 21 for airlines operating Boeing 737-900ER jets to inspect door plugs, ensuring they are properly secured. This move comes after some operators reported unspecified issues with bolts during inspections.
The FAA’s action follows the recent grounding of 171 Boeing 737 Max 9 planes due to a midair cabin blowout of a door plug on an eight-week-old Alaska Airlines Max 9 jet on January 5. While the 737-900ER is not part of the Max fleet, it shares the same door plug design, allowing for an additional emergency exit door when carriers choose to install more seats.
The FAA issued a Safety Alert for Operators, revealing that some airlines conducting additional inspections on the 737-900ER mid-exit door plugs had noted findings related to bolts during maintenance inspections. The recommendation urges air carriers to perform crucial portions of a fuselage plug assembly maintenance procedure concerning the four bolts securing the door plug to the airframe “as soon as possible.”
Alaska Airlines and United Airlines, the only two US carriers using Max 9, reported loose parts on multiple grounded Max 9 aircraft during preliminary checks in January. Thousands of flights have been canceled due to the grounding.
The FAA stated on January 21 that Max 9 planes would remain grounded until deemed safe for return to service. United extended the cancellation of Max 9 flights until January 26, and Alaska, with Max 9 planes accounting for 20% of its fleet, did not immediately disclose the duration of its extended cancellations.
In contrast to the Max 9, the Boeing 737-900ER has over 11 million hours of operation and 3.9 million flight cycles. The FAA emphasized that the door plug has not been an issue with this model. United and Alaska have initiated inspections on their 737-900ER fleets, with both airlines expressing confidence in completing the process without operational disruptions.
Delta Air Lines, another operator of the 900ER, proactively opted to inspect its fleet and expects no operational impacts. Globally, the three US carriers handle the majority of 737-900ERs with door plugs.
On January 17, the FAA completed inspections of an initial group of 40 Boeing 737 Max 9 jets, a crucial step in determining when the planes can resume flights. FAA administrator Mike Whitaker highlighted the ongoing process to restore confidence in the integrity of these plug doors. The US National Transportation Safety Board is also investigating records related to the door plug, scrutinizing whether bolts on the Alaska Airlines jet were properly secured or installed.
