What date is recognized as the Air Force's Birthday?

The date recognized as the Air Force's Birthday is generally celebrated on September 18, 1947. This marks the day the National Security Act of 1947 officially established the United States Air Force as a separate branch of the military, independent from the Army.

Choosing September 5, 1947, does not accurately reflect this significant historical event as it precedes the official creation of the Air Force. While the other options also do not correspond to the recognized birthday, it is crucial to note that September 18, 1947, is the correct date that signifies the inception of the Air Force, making the options provided inaccurate overall.