Definition
A free, one-way data service transmitted from FAA ground stations over the 978 MHz UAT (Universal Access Transceiver) link, providing aircraft equipped with a compatible ADS-B In receiver with weather and aeronautical information. Products typically include regional and CONUS NEXRAD radar imagery, METARs, TAFs, PIREPs, winds and temperatures aloft, AIRMETs, SIGMETs, NOTAMs, Special Use Airspace status, and TFRs. FIS-B is broadcast-only, advisory in nature, and intended for situational awareness, not for tactical weather avoidance.
Plain English
A free service that beams weather and flight information up to your aircraft from FAA ground stations, so you can see things like radar pictures, weather reports, and notices on a cockpit display.
Context Anchor
Pilots encounter FIS-B when using cockpit displays or portable receivers that show in-flight weather, airspace updates, or other FAA-provided flight information.
Derivation
The name describes the service plainly: it broadcasts (one-way transmission to anyone listening) flight information. The 'broadcast' part is the key idea — like a radio station, the ground stations send out the same data continuously, and any properly equipped aircraft within range can receive it.
Why Pilots Care
Gives pilots real-time weather and airspace data without making voice radio calls, supporting better in-flight decisions and safety.
Grounding Statement
FIS-B is one-way information sent from the ground to the cockpit for pilots who have equipment that can receive it.
Intuition Check
Do not assume “broadcast” means the airplane is having a two-way conversation with the system. FIS-B is information sent out for equipped aircraft to receive.
Example Sentence 1
On the cross-country, the pilot used FIS-B to monitor the line of thunderstorms developing fifty miles ahead and chose to divert early rather than press on.
Example Sentence 2
FIS-B provided graphical radar imagery that helped the crew deviate around a line of thunderstorms.