Hazard Awareness190-02207-02 Rev. B GPS 175/GNX 375 Pilot’s Guide 5-3Weather AwarenessWARNINGDO NOT RELY SOLELY ON DATALINK WEATHER FOR WEATHER INFORMATION.DATALINK WEATHER PROVIDES A SNAPSHOT IN TIME. IT MAY NOT ACCURATELYREFLECT THE CURRENT WEATHER SITUATION.NOTEDatalink weather is not intended to replace weather briefings or in-flightweather reports from AFSS or ATC.FEATURE REQUIREMENTS• GPS 175 with UAT receiver (GDL 88, GTX 345) and FIS-BOR• GNX 375 and FIS-BThe FAA provides FIS-B as a Surveillance and Broadcast Service operating on the UAT(978 MHz) frequency band. FIS-B uses a network of FAA-operated ground-basedtransceivers to transmit weather datalink information to the aircraft’s receiver on ascheduled continuous basis.5.1 Data Transmission LimitationsFIS-B broadcasts provide weather data in a repeating cycle which may take severalminutes to completely transmit all available weather data. Therefore, not all weatherdata may be immediately present upon initial FIS-B signal acquisition.5.1.1 Line of Sight ReceptionTo receive FIS-B weather information, the aircraft’s datalink receiver must be withinrange and line-of-sight of an operating ground-based transceiver. Reception may beaffected by altitude, terrain, and other factors. Per the FAA, much of the UnitedStates has FIS-B In airborne coverage at and above 3,000 feet AGL. Terminalcoverage is available at altitudes below 3,000 feet AGL and is available when flyingnear approximately 235 major U.S. airports. Surface coverage allows FIS-B groundreception at approximately 36 major U.S. airports.The Flight Information Service-Broadcast (FIS-B) Weather service is freely availablefor aircraft equipped with a capable datalink universal access transceiver (UAT).Ground stations provide uninterrupted services for the majority of the contiguousU.S., Hawaii, Guam, Puerto Rico, and parts of Alaska. No weather subscriptionservice is required. For the latest FAA ground station coverage information, visit:www.faa.gov/nextgen/programs/adsb/
