When did the U.S. military transition ranks from Private and Corporal to Airman?

The transition from the ranks of Private and Corporal to Airman in the U.S. military occurred in 1952. This change was part of a broader effort to standardize the rank structure within the U.S. Air Force as it established its identity separate from the Army. The Air Force sought to create a rank system that reflected its unique mission and culture, which led to the adoption of the Airman rank that is now prevalent in the service. The rank of Airman allowed for a more cohesive and identifiable hierarchy within the Air Force, distinguishing its members from those in the Army.

The options that reflect years other than 1952, such as 1945, 1960, and 1975, do not accurately represent this significant development within the Air Force's rank structure and timeline. Each of those years corresponds to different events in military history, but not specifically to the establishment of the Airman rank.