United States Air Force aircraft fleet retention trends

An extensive body of literature highlights the challenges of aging aircraft. The basic concern is that aircraft become more expensive to maintain and less available for operations as they age. In this technical report, we do not directly examine the age of the United States Air Force's (USAF's) aircraft. Instead, we provide historical, contextual information on the ages of aircraft designs operated by the USAF. Using two 1998 Air Force Historical Agency reports, the report traces the use of different aircraft designs in the Air Force and its predecessor organizations, dating back to the earliest days of military aviation through 1995. Since the end of World War II and the formation of the Air Force as an independent military service in 1947, there has been a secular trend for the Air Force to keep aircraft designs in operation for ever-longer periods. So, while the mean age of aircraft designs currently in operation is at an all-time high, the same statement could have been made at most times throughout the history of the Air Force. The Air Force has had, by and large, an ever-aging portfolio of designs. In theory, the Air Force could have a new aircraft that was manufactured using an old design. With the exception of a handful of designs such as the C-130, however, Air Force aircraft have typically been only a few years younger than the design from which they were manufactured.