In 1967, Day, now a major, was put in command of a squadron of F-100s in Vietnam involved in a top-secret program. Nicknamed the Misty Super Facs, their mission was to fly over North Vietnam and Laos as “forward air controllers,” selecting military targets and calling in air strikes on them. On August 26, ground fire hit Day’s plane, destroying its hydraulic controls and forcing it into a steep dive. When he ejected, he smashed against the fuselage and broke his arm in three places. North Vietnamese militiamen below, seeing his parachute open, were waiting for him when he landed. They marched Day to a camouflaged underground shelter. When he refused to answer his captors’ questions, they staged a mock execution, then hung him from a rafter by his feet for several hours. Certain that he was so badly hurt that he wouldn’t try to get away, they tied him up with loosely knotted rope. On his fifth day in the camp, while a pair of distracted teenage soldiers stood guard, he untied himself and escaped.