"Each year, the Department of Defense issues a 30-year aviation plan, intended to chart the direction of the aviation enterprise. This plan is typically relatively short on specifics, in part because 30 years is rather far to foresee in detail, particularly as that goes 25 years beyond official defense budget projections. By contrast, the most recent 30-year aviation plan released in April 2018 is full of details on specific programs, including cancellations, life extensions, and new starts. Some are explicit; others, between the lines. Some of the highlights follow."
CRS In Focus, IF10999
Congressional Research Service: https://crsreports.congress.gov/