5-20 GPS 175/GNX 375 Pilot’s Guide 190-02207-02 Rev. BHazard Awareness5.8.1 Traffic Application FailuresDuring normal operation, the “ADS: On” status annunciation means that both AIRBand ATAS applications are active. In the rare event of an application failure, it ispossible that only one of the applications may be active. The unit provides indicationsto reflect which application is no longer operational.• ADS field indicates “On”• If AIRB is active and ATAS is failed, the unit displays the system message:“ADS-B traffic alerting function inoperative”• If AIRB is failed and ATAS is active (and still capable of providing a no-bearingaural alert), “Unavailable” annunciates across the traffic displayTRAFFIC APPLICATIONSAIRB & ATAS• Both active when ADS-B is “On”(airborne traffic indications are available; ATAS arms toprovide airborne alerts)• Alerts occur when potential collision risks are determinedbased on current airborne position and trajectory and theposition and trajectories of other airborne traffic• Airborne traffic alerts only(no alerts on ground or for traffic on the ground)• Nominally allow 20 to 40 seconds for flight crew response• Provide aural alerting when traffic alerts occurSURF• Active on ground or within the terminal environment(<5 nm and <1,500 ft above field elevation)• Traffic on ground may display when SURF is active• Runway and taxiway depictions when the zoom scale is<2 nm (Traffic page only)• Depicts only traffic and ground vehicles equipped withADS-B Out
