Definition
The common traffic advisory frequency (CTAF) is a radio frequency used by pilots to communicate with each other at non-towered airports, or at towered airports when the tower is closed. In some countries, CTAF is referred to as aerodrome traffic frequency (ATF). In The United Kingdom, this frequency is referred to as SAFETYCOM.
Description
When arriving at or departing from a non-towered airport, pilots self-announce their positions on CTAF so that other pilots will know their locations and avoid traffic conflicts. For example, when beginning a visual approach, a pilot might transmit: "Oxford-Henderson traffic, Cessna Seven Three Seven Victor Whiskey, ten miles south, inbound for landing, runway two-four, VFR."
Later when entering the traffic pattern, the same pilot might call: "Oxford-Henderson traffic, Cessna Seven Three Seven Victor Whiskey, entering downwind for landing, left traffic, runway two-four." The pilot should make similar calls when turning from the downwind leg to the base leg, from the base leg to final approach, and when exiting the runway after landing.