Definition
The Airport Reservation Function (ARF) is the FAA system used to allocate and manage takeoff and landing reservations (slots) at designated High Density Traffic Airports during specified hours. Operators must obtain a reservation through the ARF system before conducting an unscheduled IFR operation at one of these airports during the controlled period.
Plain English
ARF is the FAA's online booking system for takeoff and landing slots at a small number of very busy airports. If you want to fly into one of these airports during its busy hours, you have to reserve a time first.
Context Anchor
Seen in FAA acronym lists, flight planning information, and notices for busy airports or special events where airport use may require a reservation.
Derivation
Reservation comes from a Latin root meaning “to keep back” or “hold aside.” In this aviation use, it helps to think of airport capacity being held for aircraft that have an approved reservation time.
Why Pilots Care
Pilots flying to certain high-density airports must obtain an approved reservation in advance or they will be denied takeoff or landing clearance.
Intuition Check
Do not treat an airport reservation as permission to land by itself. It reserves a time to use the airport, but the pilot must still follow normal clearances and procedures.
Example Sentence 1
Before launching the Part 91 trip into DCA, the dispatcher logged into the ARF website to secure an arrival slot within the planned ETA window.
Example Sentence 2
The flight was unable to depart because the airport reservation function slot had not been confirmed.