FLARM uses a data communication frequency in the SRD860 band or in an ISM band in different parts of the world. In e.g. Europe, the SRD860 band is used (868.2 – 868.4 MHz). In e.g. North and South America, the ISM band covering 902.2 – 927.8 MHz is used.
A FLARM system in normally installed in certified aircraft. Approved antennas are usually listed in the installation instructions. For PowerFLARM Core, this is part of the EASA approved Minor Change. For most aircraft, the FLARM AV-75 antennas should be used for external mounting. Glassfiber gliders can also use internal antennas.
More information about antenna selection and installation can be found in the document "FTD-041 Application Note FLARM Antenna Installation", which can be found on the Manuals and Documents page.