Most AAFBUs were inactivated before the 1947 USAF was established .
Some were redesignated Air Force base units ( AF BU ) , e.g. , base operating units on 26 September 1947 such as Brooks ' 306th , Barksdale 's 2621st , and Williams ' 3010th .
Most AAFBUs were inactivated before the 1947 USAF was established , but some were redesignated Air Force base units ( AF BU ) , e.g. , base operating units on 26 September 1947 such as Brooks ' 306th , Barksdale 's 2621st , and Williams ' 3010th .