Core Points - Southwest Airlines has begun flying its first Boeing 737 Max 8 equipped with a secondary flight deck barrier, marking a significant milestone in aviation safety since the September 11, 2001, terror attacks [1][2] - The Federal Aviation Administration (FAA) has mandated that new commercial airliners in the U.S. must include these secondary barriers, with a compliance deadline set for July 2026 [5][12] - Southwest Airlines plans to accept delivery of approximately 25 more Boeing airplanes with the barriers this year, demonstrating its commitment to immediate compliance with the new safety regulations [6][9] Industry Context - The introduction of secondary barriers has been a long-sought safety measure following the hijackings on September 11, 2001, aimed at enhancing cockpit security [2][9] - Major aircraft manufacturers, including Boeing and Airbus, have started delivering planes with these barriers in compliance with the new FAA regulation [2][12] - Most airlines have indicated they will utilize the extension provided by the FAA and may not implement the barriers until closer to the deadline [6][12]