U.S. Navy MH-60S Knighthawk
Pilots from Davis-Monthan Air Force Base, Ariz. maintain contact with rescuers, Sept. 18, 2013, during a field training exercise in southern Arizona. During the simulation, downed pilots are giving coordinates and attempting to be spotted by A-10 Thunderbolts for rescue. (U.S. Air Force photo by Airman 1st Class Chris Massey/Released)