Patrick McDonald autographs a a handout after touring a 307th Bomb Wing B-52H Stratofortress, June 4, 2014, Barksdale Air Force Base, La. McDonald, a U.S. Army veteran and U.S. Paralympic Curling Team captain, joined the American300 Tours to share his experience with fellow military service members as part of the tour's 'Never Quit Series'. (U.S. Air Force photo by Master Sgt. Greg Steele/Released)