(NewsNation) — Southwest Airlines has taken its next steps in safety measures for its aircraft.

The airline has introduced a collapsible barrier designed to stop passengers from accessing the front galley next to the cockpit when a pilot needs to leave for a restroom break or other reasons. Flight attendants must set up this barrier whenever a pilot steps out of the cockpit.

The company completed its first flight with the secondary barrier Aug. 29.

“This requirement traces back to Sept. 11. After that incident, efforts have been made to enhance the security of the flight deck,” stated Justin Jones, the executive vice president of operations at Southwest Airlines.

Southwest Airlines noted it is among the first U.S. airlines to adopt this new onboard security measure. Previously, their procedure required flight attendants to face the cabin while using a beverage cart to prevent passengers from advancing toward the galley.

This initiative follows two years after the Federal Aviation Administration announced a rule mandating these barriers on all new commercial aircraft. Initially, the requirement was supposed to start last month, but the FAA has postponed the deadline to install barriers on new planes until 2026.

Southwest Airlines anticipates having over 25 aircraft fitted with the device in service by the end of 2025.

The airline will soon require travelers who don’t fit within the armrests of their seat to pay for an extra one in advance early next year.