"Federal Aviation Administration (FAA) programs are funded under four broad budget accounts: operations and maintenance (such as air traffic control and aviation safety functions); facilities and equipment (such as control towers and navigation beacons); grants for airports under the Airport Improvement Program (AIP); and civil aviation research conducted or sponsored by FAA. Additionally, certain aviation programs are administered by the Department of Transportation (DOT) Office of the Secretary, including the Essential Air Service (EAS) program, which subsidizes airline service to certain small or isolated communities. These programs are funded primarily through a special trust fund, the Airport and Airway Trust Fund (AATF), and, in part, through general fund contributions. The FAA Reauthorization Act of 2018 (P.L. 115-254) authorizes AATF taxes and revenue collections and civil aviation program expenditures through FY2023."
CRS Report for Congress, R42781
Congressional Research Service: https://crsreports.congress.gov/