Common Traffic Advisory Frequency (CTAF)

A frequency designed for the purpose of carrying out airport advisory practices while operating to or from an airport without an operating control tower. The CTAF may be a UNICOM, Multicom, FSS, or tower frequency and is identified in appropriate aeronautical publications.

Source: FAA Pilot/Controller Glossary (definition from the 2023 edition; current: Change 1 of 7 August 2025).

Reference: AC 90-42, Traffic Advisory Practices at Airports Without Operating Control Towers.