Definition
A free, ground-based service that transmits aviation weather and aeronautical information to properly equipped aircraft over the 978 MHz UAT (Universal Access Transceiver) data link. FIS-B is part of the FAA's ADS-B infrastructure and provides products such as METARs, TAFs, NEXRAD radar imagery, AIRMETs, SIGMETs, PIREPs, NOTAMs, TFRs, winds and temperatures aloft, and special use airspace status. It is one-way (ground to aircraft) and intended to support situational awareness, not real-time tactical weather avoidance.
Plain English
FIS-B is a free FAA service that beams weather reports, radar pictures, and other flight information up to your cockpit display while you fly, as long as you have the right receiver onboard.
Context Anchor
Seen in discussions of cockpit weather displays, ADS-B equipment, and in-flight information services.
Derivation
The name describes how it works. 'Flight Information Service' is the category of data being sent (weather and aeronautical info pilots use in flight). 'Broadcast' means it is transmitted continuously from ground stations to any aircraft in range with a compatible receiver — like a radio station rather than a phone call. No request is needed; you just tune in.
Why Pilots Care
Gives pilots access to updated weather and airspace information without voice requests, supporting better enroute decisions and safety.
Intuition Check
Do not read “broadcast” as a two-way conversation or a personal clearance. FIS B sends information out to equipped aircraft; it does not mean ATC is talking directly to you.
Example Sentence 1
Before crossing the ridge, the pilot checked the FIS-B NEXRAD display and saw a line of building cells, so she diverted south while still well clear of the weather.
Example Sentence 2
FIS-B delivered the latest METARs and temporary flight restrictions directly to the moving map display.