U.S. Air Force Col. Tad Clark, 52nd Fighter Wing vice commander, poses with a picture of his father after the prisoners of war and missing in action breakfast at Spangdahlem Air Base, Germany, Sept. 8, 2017. Clark's father, Robert Clark, was a bombardier navigator whose remains were missing for more than 30 years after his aircraft went down over North Vietnam on Jan. 10, 1973. (U.S. Air Force photo by Senior Airman Preston Cherry)