U.S. Air Force Lt. Col. Philippe Malebranche, right, and Maj. Benjamin Robbins, F-16 pilots with the 177th Fighter Wing, walk to their post-flight briefing after a training mission during Thracian Star, a bilateral training exercise to enhance interoperability with the Bulgarian air force, at Graf Ignatievo Air Base, Bulgaria, on July 13, 2015. (U.S. Air National Guard photo by Master Sgt. Andrew J. Moseley/Released)