When the tower is temporarily closed (or operated on a part-time basis), use the CTAF to self-announce your position or intentions, just like you do at Class E and G airports. Keep in mind, if the tower is due to open shortly, you should have their frequency tuned in advance to speak with the controller.

When operating at an airport where the control tower is closed, the field becomes an uncontrolled aerodrome, and safety relies entirely on pilot self-announcement and "see-and-avoid" discipline. Pilots must switch their radio to the Common Traffic Advisory Frequency (CTAF) or Mandatory Frequency (MF) to broadcast their position and intentions. Standard procedures involve overflying the field at 500 feet above the traffic pattern to check the windsock and observe the flow of any existing traffic. Before entering the pattern—typically on a 45-degree angle to the downwind leg—you must state your aircraft type, location, and planned runway. For departures, you should announce your taxi and takeoff intentions clearly. In 2026, many pilots also utilize ADS-B technology on their cockpit displays to "see" other aircraft electronically, but this never replaces the requirement for clear voice transmissions and a constant visual scan for other planes, especially those without functioning radios.