An oxygen mask hangs in the cockpit of a U.S. KC-135 Stratotanker assigned to 22nd Expeditionary Air Refueling Squadron during a training flight over the Black Sea May 29, 2020. Training outside the U.S. enables aircrew and Airmen to become familiar with other theaters and airspace, and enhances enduring skills and relationships necessary to confront a broad range of global challenges in support of the National Defense Strategy. (U.S. Air Force photo by Staff Sgt. Joshua Magbanua)