US Air Force officially accepts first Boeing F-15EX fighter jet 12 March 2021 (Last Updated March 12th, 2021 11:13) The US Air Force (USAF) has officially accepted the first F-15EX fighter jet at Boeing’s St Louis facility in Missouri, US. The first F-15EX departs a Boeing facility in St. Louis, Mo, in route to Eglin Air Force Base, Fla. Credit: Boeing Co. Share Article The US Air Force (USAF) has officially accepted the first F-15EX fighter jet at Boeing’s St Louis facility in Missouri, US. The two-seat fighter jet departed the facility and headed to Eglin Air Force Base (AFB) in Florida for testing.