An Aerodrome Traffic Frequency (ATF) is normally designated for active uncontrolled aerodromes that do not meet the criteria to have a Mandatory Frequency (MF) assigned. The ATF is established to ensure that all radio-equipped aircraft operating on the ground or within the area are listening on a common frequency and following common reporting procedures. In Canada, the ATF will normally be the frequency of the Universal Communications (UNICOM) facility where one exists or 123.2 MHz where a UNICOM does not exist. The specific frequency, distance and altitude within which use of the ATF is required will be published in the appropriate flight supplements.
Trained vehicle operators who possess a valid radiotelephone licence and authorized to do so, can communicate with pilots using two-way communication on the ATF and provide information such as:
position of vehicles on the manoeuvring area
position of other aircraft on the manoeuvring area
runway condition, if known
Personnel providing UNICOM or Air/Ground radio can also advise pilots on the ATF with the same information. When communications cannot be established with personnel on the ground (no reply or NORDO) or the status of the runway is unknown, it is the pilot’s responsibility to visually ascertain the runway condition before landing or taking off. For airborne traffic deconfliction, all aircraft reports required for operating within and prior to entering an ATF area shall be broadcast "in the blind". Any conflicts that become apparent from these broadcasts must be resolved by the pilots of the aircraft concerned. Refer to the article Uncontrolled Aerodromes - Communications for specific reporting requirements.
The designation of an ATF is not limited to aerodromes only. An ATF may also be designated for use in certain areas, other than the area immediately surrounding an aerodrome, where VFR traffic activity is high, and there is a safety benefit to ensuring that all traffic monitor the same frequency. For example, an ATF area could be established along a frequently flown corridor between two uncontrolled aerodromes or in a designated training area. All aircraft operating within the area, below a certain altitude, would be requested to monitor and report intentions on one frequency.