Definition
A free, ground-based broadcast service transmitted on the 978 MHz UAT (Universal Access Transceiver) ADS-B link that delivers weather and aeronautical information to properly equipped aircraft. FIS-B products include graphical and textual weather (such as NEXRAD radar imagery, METARs, TAFs, AIRMETs, SIGMETs, PIREPs, and winds aloft) along with NOTAMs, TFRs, and special use airspace status. The service is one-way (ground-to-air) and requires a 978 MHz UAT ADS-B In receiver to use.
Plain English
A free service that beams weather and flight information up to your aircraft from ground stations, so you can see things like radar pictures, weather reports, and airspace alerts on a cockpit display.
Context Anchor
You see FIS-B in discussions of cockpit weather displays, ADS-B equipment, and data link weather products.
Derivation
The name describes exactly what the service does: it provides flight information by broadcast — meaning it is sent out continuously to anyone with the right receiver, rather than requested by an individual aircraft.
Why Pilots Care
It delivers continuous weather information without requiring voice requests, improving situational awareness and supporting safer routing decisions.
Analogy
FIS-B is like a local radio station for flight information: the ground station sends information out, and equipped aircraft nearby can receive it.
Intuition Check
Do not think of FIS-B as a two-way request service. The aircraft receives information that is broadcast from the ground; it does not call up each product by talking back to the station.
Example Sentence 1
Before takeoff, the pilot confirmed her ADS-B In receiver was working so she could pull up FIS-B weather and TFR information once airborne.
Example Sentence 2
FIS-B broadcasts allowed the flight crew to monitor convective activity updates without using the radio.