U.S. Air Force Lt. Col. Philippe Malebranche, F-16 pilot with the 177th Fighter Wing, prepares to start the turbine engine, close the canopy and taxi his Fighting Falcon to take off on 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)