Emergency Airworthiness Directive (AD) 2024-02-51 is sent to owners and operators of The Boeing Company Model 737-9 airplanes. Background This emergency AD was prompted by a report of an in-flight departure of a mid cabin door plug, which resulted in a rapid decompression of the airplane. The FAA is issuing this AD to address the potential in-flight loss of a mid cabin door plug, which could result in injury to passengers and crew, the door impacting the airplane, and/or loss of control of the airplane. FAA's Determination The FAA is issuing this AD because the agency has determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. AD Requirements This AD prohibits further flight of affected airplanes, until the airplane is inspected and all applicable corrective actions have been performed using a method approved by the Manager, AIR-520, Continued Operational Safety Branch, FAA. Interim Action The FAA considers this AD to be an interim action.