CTAF & UNICOM (Non-Towered Communications)

At an airport with no operating control tower — the majority of public-use airports in the United States — no controller sequences arrivals or issues clearances. Instead, pilots coordinate with one another by broadcasting their positions and intentions in the blind on a designated Common Traffic Advisory Frequency, or CTAF. The CTAF is a concept rather than a single number: it is whatever frequency the airport uses for local self-announce traffic, which may be a dedicated CTAF, a UNICOM frequency, a MULTICOM frequency (122.9 MHz where no other is assigned), or the tower frequency when a part-time tower is closed. The CTAF for a given field is published on the sectional chart and in the Chart Supplement and is marked with a white "C" in a solid circle. The recommended traffic advisory practices are described in AIM paragraph 4-1-9 and Advisory Circular 90-66.

Self-announcing is not a clearance and confers no authority. It is a courtesy broadcast that lets other pilots build a mental picture of the traffic flow. The recommended inbound calls are: an initial report roughly 10 miles out stating position and intentions; then reports entering the downwind, turning base, and turning final; and a final call when clear of the runway. Outbound, a pilot announces before taxiing and again before taking the runway for departure. Every transmission should begin and end with the airport name so pilots on a shared frequency — and several nearby airports can share 122.9 — know which field is being discussed. A model call is: "Smithville traffic, Cessna one-two-three-four-five, ten miles south, inbound for landing, full-stop, Smithville." Pilots are cautioned not to use the phrase "taking the active," because at a non-towered field there is no controller designating an active runway; the pilot in command selects a runway based on wind and the observed flow.

UNICOM (universal communications) is a non-government air-ground radio station licensed to provide advisory and airport information. It is frequently operated by the fixed-base operator on the field. A pilot may call UNICOM to request an airport advisory — the favored runway, known traffic, wind, and altimeter — or to arrange services such as fuel, a rental car, or crew transport. A UNICOM operator is not a controller: any information given is advisory only, may be provided by a non-pilot, and does not relieve the pilot of the responsibility to see and avoid other aircraft and to determine the safe runway for the conditions. Where an Automated Weather Observing System or Automated Surface Observing System is present, current altimeter and wind should be taken from that source rather than from UNICOM.

The distinction from a control tower is fundamental. A tower issues instructions and clearances that pilots must comply with, sequences traffic, and separates aircraft in its surface area and airspace. CTAF self-announcing does none of that — it distributes information so that pilots can separate themselves. This is why disciplined, standard-phraseology position calls and continuous listening on the correct frequency matter so much at non-towered fields: the system depends entirely on every pilot broadcasting clearly, listening carefully, and keeping eyes outside the cockpit.

Non-towered operations are where most primary flight training happens, so CTAF and UNICOM discipline is one of the earliest habits a school instills. Poor radio technique — omitting the airport name, using tower-style phraseology, or stepping on other transmissions — is a common finding on stage checks and a frequent contributor to the near-midair and runway-incursion reports that come out of busy non-towered fields. A school that trains crisp, standard self-announce calls from the first pattern lesson produces safer solo students and cleaner checkrides.

For flying clubs and schools based at a non-towered airport, the CTAF culture on the field is partly theirs to set. Consistent phraseology across every instructor and every rental pilot reduces confusion, and briefing based members on the shared-frequency reality — that several airports may be on 122.9 and that UNICOM advice is advisory only — prevents the complacency that treats a UNICOM operator as if they were a controller. It is also worth reinforcing that see-and-avoid, not the radio, is the primary defense against a conflict.

Aviatize's training management module lets a school define non-towered communication objectives — standard self-announce calls, correct frequency selection from the Chart Supplement, and the UNICOM-versus-tower distinction — as trackable syllabus items, so an instructor can grade radio phraseology against the Airman Certification Standards and a chief instructor can see that the competency was covered before solo.

Through ground training and checking, the same procedures can be built into pre-solo briefings and periodic refreshers for club members and rental pilots, keeping phraseology consistent across everyone who flies from the field. Recording that the material was delivered gives the school an auditable trail for its Part 141 or club safety documentation.