Carr began his military service with the U.S. Navy, and in 1950 he was appointed a midshipman with the Naval Reserve Officers Training Corps (NROTC) detachment at the University of Southern California. Upon graduation in 1954, he received his commission in the U.S. Marine Corps and subsequently reported to The Basic School at Marine Corps Base Quantico, Virginia. He received flight training at Naval Air Station Pensacola, Florida, and Naval Air Station Kingsville, Texas, and was then assigned to VMF(AW)-114 where he gained experience in the F9F Cougar and the F-6A Skyray.