Mandatory Frequency (MF)
In various regions, aviation authorities may establish a Mandatory Frequency (MF) for use at certain uncontrolled aerodromes or during specific hours at these locations. An MF area is set up when the volume and type of aircraft traffic suggest that implementing MF procedures would enhance safety. Once an MF is established, the designated frequency, along with the distance and altitude where MF rules apply, will be made public.
Aircraft operating within this MF area, whether on the ground or in the air, must have a working radio that allows for two-way communication. This requirement is waived if a Flight Service Station (FSS), Community Aerodrome Radio Station (CARS), or a similar agency is in operation, provided that specific prior arrangements have been made.
Reporting Procedures
There may or may not be a ground station active at the aerodrome where the MF area has been established. If a ground station, such as an FSS or CARS, is operational, all necessary aircraft reports for entering and operating within the MF area must be directed to that ground station. Conversely, if there is no ground station available or it is not functioning, all required aircraft reports must be broadcasted “in the blind.” For detailed reporting requirements, please refer to the article on Uncontrolled Aerodromes – Communications.
