Garmin GNX 375, Pilot'S Manual

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Hazard Awareness
190-02207-02 Rev. B GPS 175/GNX 375 Pilot’s Guide 5-3
Weather Awareness
WARNING
DO NOT RELY SOLELY ON DATALINK WEATHER FOR WEATHER INFORMATION.
DATALINK WEATHER PROVIDES A SNAPSHOT IN TIME. IT MAY NOT ACCURATELY
REFLECT THE CURRENT WEATHER SITUATION.
NOTE
Datalink weather is not intended to replace weather briefings or in-flight
weather reports from AFSS or ATC.
FEATURE REQUIREMENTS
•
GPS 175 with UAT receiver (GDL 88, GTX 345) and FIS-B
OR
•
GNX 375 and FIS-B
The 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-based
transceivers to transmit weather datalink information to the aircraft’s receiver on a
scheduled continuous basis.
5.1 Data Transmission Limitations
FIS-B broadcasts provide weather data in a repeating cycle which may take several
minutes to completely transmit all available weather data. Therefore, not all weather
data may be immediately present upon initial FIS-B signal acquisition.
5.1.1 Line of Sight Reception
To receive FIS-B weather information, the aircraft’s datalink receiver must be within
range and line-of-sight of an operating ground-based transceiver. Reception may be
affected by altitude, terrain, and other factors. Per the FAA, much of the United
States has FIS-B In airborne coverage at and above 3,000 feet AGL. Terminal
coverage is available at altitudes below 3,000 feet AGL and is available when flying
near approximately 235 major U.S. airports. Surface coverage allows FIS-B ground
reception at approximately 36 major U.S. airports.
The Flight Information Service-Broadcast (FIS-B) Weather service is freely available
for aircraft equipped with a capable datalink universal access transceiver (UAT).
Ground stations provide uninterrupted services for the majority of the contiguous
U.S., Hawaii, Guam, Puerto Rico, and parts of Alaska. No weather subscription
service is required. For the latest FAA ground station coverage information, visit:
www.faa.gov/nextgen/programs/adsb/