SAFA Skysailor Magazine

16 SKY SAILOR July | August 2023 Adventures in the land of FLARM by Iain Clarke – SAFA Safety Management Officer In the January/February 2021 issue of SkySailor, I wrote about tools for tracking and explored some of the software options that were out there. FLARM and its associated technology FANET did not rate a mention. It’s time to rectify this. What is FLARM? The FLARM ( FL ight al ARM ) system is an electronic conspicuity beacon system used for collision avoidance. It is widely used in Europe and particularly in sailplanes in the Alps. There are also claims that 50% of GA aircraft in Europe carry FLARM. The broadcast range of FLARM beacons is typically about 20km, but ranges of 40km are achievable. Here in Aus- tralia, Gliding Australia reckon about 500 plus of their aircraft are fitted with FLARM. These units are pretty high-end though, weighing in at around the $3k mark. FLARM devices can work as beacons only or additionally as receivers. If beacon only, other FLARM-equipped aircraft will see you, but you won’t know about them. If operating as a receiver you need to explore how that data is presented to you. The critical capability of FLARM is that it extrapolates each aircrafts course data and presents a projection of potential collisions. What is FANET+? The FANET+ ( F lying A d-hoc NET work) is a protocol that allows the propagation or ‘bouncing’ of FLARM/FANET traffic from one aircraft to another, either by other FLARM/ FANET equipped aircraft, or via ground stations. This means that aircraft beyond the range of a beacon on a particular aircraft may still become aware of its presence. This diagram from an article in Cross Country magazine illustrates how the system works: Figure 1: How FANET works Courtesy XC Mag In the diagram, Paraglider C can ‘see’ paraglider D via paragliders A and B and the ground station. The ‘+’ implementation of FANET allows for passing other data, including your current weather conditions. We don’t use any old FLARM! The radio spectrum landscape in Australia is regulated by the Australian Communications and Media Authority (ACMA). ACMA has set aside the 868 MHz portion of the spectrum for mobile telephone communications. This is painful as 868 MHz is the frequency that is used for FLARM in Europe and the UK. FLARM in the USA and NZ operates on 915 MHz, which is also set aside for other uses in Australia. FLARM in Australia operates on 921 MHz. The implication of this is that ordering that ‘ripper, you beaut’ instrument made in Europe fitted with FLARM is probably not going to be of any use here. You need to do your research and ask the question of the retailer, or the manufacturer, ‘Which frequency is FLARM operating on in this