U.S. Air Force Staff Sgt. Travis Martinez, 31st Aircraft Maintenance Squadron dedicated crew chief, guides a U.S. Air Force F-16 Fighting Falcon with a TowFLEXX during exercise Thracian Viper 20, Sept. 24, 2020, at Graf Ignatievo Air Base, Bulgaria. U.S. Airmen participated in Thracian Viper 20, a multilateral training exercise, which allows both U.S. Airmen and Bulgarian forces to extend joint warfighting capability through operational and tactical training. The exercise provided an opportunity for U.S. Airmen to train with partners and NATO allies in order to improve interoperability and readiness. (U.S. Air Force photo by Airman 1st Class Ericka A. Woolever)