The New F-15EX Flies For The First Time Ahead Of The First Deliveries Later This Year The New F-15EX Flies For The First Time Ahead Of The First Deliveries Later This Year The F-15EX AF 20-0001 photographed immediately after the landing gear retraction during the takeoff. (Photo: @vikingaeroimages) The new advanced F-15EX Eagles will replace the older F-15Cs that have long surpassed their expected service-life estimates. The first new F-15EX built for the U.S. Air Force took the skies for the first time today from Boeing’s plant at Lambert International Airport in St. Louis. The aircraft, serial AF 20-0001, blasted off from runway 30L at about 1:53 pm ET, using the callsign RED 62 [a previous version of the story reported the c/s as BREM but we were informed it was RED, another Boeing flight test callsign], for a 90-minute test flight. This maiden flight was initially scheduled for yesterday, however it had to be delayed because of the weather. The photos of the aircraft were kindly shared with us by aviation photographer vikingaeroimages, based in St. Louis.