Mullins entered pilot training as an aviation cadet in 1948 and graduated in 1949 with a commission as a second lieutenant.

In July 1954, Mullins entered aircraft observer/bombardier training at James Connally Air Force Base, Texas, in preparation for an assignment in January 1955 to the 96th Bombardment Wing at Altus Air Force Base, Oklahoma, as a B-47 aircraft commander.

He received a Bachelor of Arts degree in business administration from the University of Omaha in 1964, attended the Air War College at Maxwell Air Force Base, Alabama from August 1966 to July 1967, and then completed RF-4C combat crew training.

Mullins was assigned to Headquarters U.S. Air Force, Washington, D.C., in August 1969 in the Directorate of Operational Requirements and Development Plans, Office of the Deputy Chief of Staff, Research and Development, where he served as chief of the Aircraft Division.

This article incorporates public domain material from the United States Air Force