Don Cagle enlisted in the Air Force in 1956, completed training in the B-52B at Castle AFB, Calif., and was assigned to Minot AFB for transition training to the B-52H in August 1964.
During the UFO events, when it became apparent the pilots were being asked to search for a UFO, he excused himself from the flight deck leaving Partin and Runyon in charge. Cagle had plans to be in Atlanta for a job interview with Delta Airlines later that day, and had already missed an appointment one month earlier, due to an unannounced Operational Readiness Inspection (ORI) on base. His concern was any direct personal involvement would require him to remain at Minot, and he would miss another opportunity for a new career. However, he made the appointment, was hired by Delta, and after thirteen years of military service resigned his commission in January 1969. Cagle was an instructor and evaluation pilot at Delta, before moving to management as Chief Pilot of the International Base when they took over the assets of Pan-Am. He retired from Delta in 1997 and continues to do consulting work in aviation.
Cagle did not attend the B-52 crew debriefing later in the morning, and was not interviewed during the official investigation. During several recent interviews (2000, 2001, 2005), he claims to have no recollection of the UFO events.