ABSTRACT
Several airborne collision avoidance system (ACAS) technologies have been developed since the 1950s; this chapter focuses on the traffic alert and collision avoidance system (TCAS). FLARM is a traffic awareness and collision avoidance technology for General Aviation (GA) light aircraft, helicopters, gliders and unmanned aerial vehicles (UAVs). The system consists of one TCAS computer, two directional antennas, a control panel and two displays. TCAS operates in conjunction with the Mode S surveillance system which includes two transponders, a control panel and antenna. Cockpit display of traffic information (CDTI) can be enhanced with an ADS-B traffic advisory system (ATAS). Newer FLARM devices which are based on the improved PowerFLARM technology optionally incorporate an ADS-B and transponder (SSR) Mode-C/S receiver. This enables additional aircraft to be included in the collision prediction algorithm. Besides issuing collision warnings, most FLARM systems also show nearby aircraft on a radar screen.
