 After graduating from basic training, Sigmon trained as a defensive aerial gunner on a B-52H bomber at Castle Air Force Base, California, and spent the next 3½ years stationed at Grand Forks Air Force Base, North Dakota.He was the only enlisted crewmember on a B-52H flight crew and was solely responsible for the defense of the aircraft while in flight.Most notably, as a member of one leg of our Nation's nuclear deterrent triad, Sigmon sat on "nuclear alert" for extended periods during the entire period of time he was assigned to Grand Forks.