When John Fairfield visited an Air Force recruiter, he became convinced he should be a navigator to gain additional aviation education before becoming a pilot. He attended navigator training and served as a B-52 Navigator, eventually becoming a check airman and a Navigator-Bombadier. Due to his exceptional performance and attitude, he was selected to attend Air Force Undergraduate Pilot Training as the only Navigator released from Strategic Air Command for this school.

He performed extremely well in pilot training, and had his choice of assignments. He elected to remain in Air Training Command as an Instructor Pilot, to gain additional flight experience. At Williams Air Force Base he became the base expert in T-37 spin recovery training, administering this training to students and instructors alike. After gaining additional flying experience, John volunteered for combat duty in Vietnam.

Following F-4 Replacement Training Unit training, he arrived at the 8th Tactical Fighter Wing, at Ubon Royal Thai Air Base, just as Operation Linebacker commenced. He quickly became a flight commander and flight leader on missions over Hanoi, at the time the most heavily-defended area in the world. He led combat flights during both Linebacker I and Linebacker II.

After Ubon, John was assigned to the Pentagon to manage the Air Force fuel program. A few months after assuming that position, the 1973 Fuel Crisis occurred, and it was his job to ensure that the Air Force could continue flying with drastically reduced fuel stores. Because of his performance in this position, he was promoted from Captain to Colonel in four years, considered an impossibility during peacetime!

John eventually got back into the cockpit in the B-52 and served numerous roles, including becoming a Wing Commander a few weeks after arriving on base when his wing failed an Operational Readiness Inspection (ORI) and the previous Wing Commander was fired. He instituted a corrective action program that resulted in his wing achieving the best bombing scores in the history of the Strategic Air Command during the ORI re-test.

Numerous other assignments, including another tour at the Pentagon, led to his selection as Lieutenant General (three-star). For most of these assignments, General Fairfield was not selected for these positions because of his in-depth knowledge of the intricacies of the tasks, but for his leadership and for his ability to inspire his men and women to achieve the goals of their mission.

General Fairfield retired from active duty in 1997.