Three U.S. Air Force pilots from the 555th Fighter Squadron, Aviano Air Base, Italy, perform post-flight checks after landing at Graf Ignatievo Air Base, Bulgaria, Sept. 18, 2020. The pilots will participate in Thracian Viper 20, a multilateral training exercise, which allows both U.S. Air Force Airmen and Bulgarian forces to extend joint warfighting capability through operational and tactical training. (U.S. Air Force photo by Airman 1st Class Ericka A. Woolever)