6/25/2012 - B-52H Stratofortress bombers sit on the flightline on Barksdale Air Force Base, La., June 25. Due to constant exposure to sunlight, a B-52 must be painted every four years to maintain its dark grey color. The dark grey color helps the B-52 blend in when flying at higher altitudes, at night or over large bodies of water. (U.S. Air Force photo/Airman 1st Class Micaiah Anthony)(RELEASED)