Core Points - Southwest Airlines has introduced its first aircraft equipped with a secondary cockpit barrier to enhance flight safety by preventing unauthorized access [1][3] - The new Boeing 737 MAX8 aircraft took off from Phoenix to Denver, featuring a protective door between the cockpit and passenger cabin [3] - The implementation of cockpit barriers follows the 2001 "911" terrorist attacks, which raised concerns about cockpit security in the U.S. [5] Regulatory Background - In 2018, the U.S. Congress passed legislation mandating the Federal Aviation Administration (FAA) to establish regulations requiring new commercial aircraft to be equipped with secondary cockpit barriers [5] - The FAA's final version of the regulations was released in June 2023, requiring all commercial aircraft operating in the U.S. to install these barriers [7] - The original deadline for compliance was set for August 25, 2023, but was extended to July 2026 due to requests from several airlines [7] Financial Aspects - The estimated cost for purchasing and installing a secondary cockpit barrier is approximately $35,000 [7] - Southwest Airlines plans to receive about 25 additional Boeing aircraft equipped with these barriers within the year [3]