What does CTAF stand for and what is it used for at a non-towered airport?

CTAF stands for Common Traffic Advisory Frequency, and it is a use rather than a station: the single frequency on which pilots at a non-towered airport, or at a towered airport when the tower is closed, announce their positions and intentions to one another. Because there is no controller, nothing said on it is a clearance and nobody has authority over anyone else — the entire system depends on pilots self-announcing and building a shared picture. The frequency is published in chart supplements and on sectional charts, and it may be the airport's UNICOM, a MULTICOM, or a tower frequency operating in advisory mode after hours. For a remote pilot the value is mainly in listening: monitoring CTAF near a non-towered field gives real-time knowledge of who is inbound, on which runway, and how far out, which is far better information than any chart provides. Announcing an unmanned operation is accepted practice, but it confers no priority and the obligation to yield to all aircraft is unchanged.

CTAF is the Common Traffic Advisory Frequency, used by pilots at non-towered airports to self-announce positions and intentions to one another.

The Common Traffic Advisory Frequency is used for self-announcement at non-towered airports and at towered airports when the tower is closed. It may be a UNICOM, MULTICOM or tower frequency, and is published in chart supplements.

Common, Traffic, Advisory. Shared frequency, about traffic, and advisory only — nobody is in charge.

A towered airport's frequency becomes the CTAF when the tower closes, so the same frequency changes character by time of day.

• •Expecting clearances on CTAF
• •Confusing the UNICOM station with the CTAF function
• •Assuming an announced operation creates priority