Flight Information Service (FIS) – Aviation Glossary

Overview

Flight Information Service (FIS) is a cornerstone of safe and efficient flight operations worldwide. Unlike Air Traffic Control (ATC), which manages aircraft separation and clearances in controlled airspace, FIS focuses exclusively on providing pilots with vital, real-time information to support situational awareness and decision-making. This information covers aeronautical, meteorological, and operational aspects, delivered both to aircraft in flight and on the ground.

FIS is especially critical in uncontrolled airspace—such as Class G or Class E—where ATC coverage may be limited or absent. In such environments, pilots rely heavily on FIS for updates about weather, airspace restrictions, NOTAMs, and aerodrome status. FIS is provided by ground-based information centers, dedicated FIS units, or en-route sector controllers, using a range of communications: VHF, HF, and increasingly, digital data links.

The International Civil Aviation Organization (ICAO) defines FIS in Doc 4444 as “a service provided for the purpose of giving advice and information useful for the safe and efficient conduct of flights.” It forms one of three pillars of Air Traffic Services (ATS), alongside Air Traffic Control and Alerting Service (Annex 11).

Types of Flight Information Service

Basic Flight Information Service (Basic FIS)

Basic FIS is the foundation of information provision in non-radar environments. Here, trained officers provide pilots with essential information—like weather (METARs, TAFs), NOTAMs, navigation aid status, and general traffic advisories—using real-time and pre-published sources.

• Particularly important for Visual Flight Rules (VFR) pilots in uncontrolled airspace.
• Delivered via VHF/HF radio or automated broadcasts (such as ATIS).
• Provides general, not specific, traffic advisories due to lack of surveillance capability.
• Widely used in countries with large areas of uncontrolled airspace (e.g., Canada, Australia, US).

ICAO Doc 4444 specifies that Basic FIS should be made available to all aircraft likely to be affected by the information, especially those not receiving it through other means.

Radar Flight Information Service

Radar FIS builds on Basic FIS by leveraging radar or ADS-B surveillance to provide more precise and timely data, especially about other traffic.

• Controllers can give specific traffic advisories (location, altitude, heading).
• Enhances safety in busy Class E and G airspace where full ATC separation is not provided.
• Traffic information remains advisory—pilots are responsible for separation.
• Used in systems such as Lower Airspace Radar Service (LARS) in the UK.

The use of radar or ADS-B allows FIS providers to tailor information to the real-time position of aircraft, improving relevance and timeliness.

Digital Flight Information Services

Digital FIS represents the evolution of traditional voice-based services, using automated, data-linked networks to deliver information directly to cockpit displays.

• Key technologies: ADS-B, FIS-B, CPDLC.
• Information includes graphical weather, textual weather (METAR, TAF), NOTAMs, Special Use Airspace (SUA) status, and airport operational data.
• Reduces radio congestion and minimizes human error.
• Information is updated frequently and can be graphical (easier to interpret).

Digital FIS is recognized by ICAO Annex 10 and Doc 4444 as a key element in modern, congested airspace. In the US, FIS-B is part of the FAA’s NextGen initiative, while Europe’s Data Link Services (DLS) provide similar capabilities.

Core Digital FIS Technologies

Automatic Dependent Surveillance–Broadcast (ADS-B)

ADS-B is a surveillance technology enabling aircraft to automatically broadcast position, velocity, and identification data derived from onboard navigation systems (GPS).

• “Automatic” = no pilot or controller input required.
• “Dependent” = relies on navigation system accuracy.
• “Broadcast” = data available to any compatible receiver.
• Two main frequencies:
  • 1090ES (1090 MHz Extended Squitter) – Standard for commercial, high-altitude, and international operations.
  • 978 MHz UAT (Universal Access Transceiver) – Used mainly by US general aviation below 18,000 feet.

ADS-B Out transmits aircraft data; ADS-B In receives broadcasts from others and supports services like FIS-B and TIS-B.

ADS-B has revolutionized airspace management, supporting concepts like reduced separation and improved search and rescue. ICAO Annex 10, Volume IV, details global ADS-B standards.

Flight Information Service–Broadcast (FIS-B)

FIS-B is a digital broadcast system providing a suite of aeronautical and weather data to aircraft, primarily in the US over 978 MHz UAT.

• Delivers METARs, TAFs, NEXRAD weather imagery, NOTAMs, PIREPs, AIRMETs, SIGMETs, winds aloft, SUA status, and more.
• Broadcasts continuously—any equipped aircraft can receive data.
• Information is presented graphically and textually in the cockpit.
• Advisory in nature; not a substitute for official weather briefings.

FIS-B is a key part of FAA NextGen and available at no cost to users within coverage.

Traffic Information Service–Broadcast (TIS-B)

TIS-B broadcasts real-time positions of nearby aircraft not equipped with ADS-B Out, enhancing traffic awareness for pilots with ADS-B In.

• “Client-based” (broadcast only for aircraft transmitting ADS-B Out and receiving ADS-B In).
• Coverage area is a 30nm “hockey puck” around the client aircraft.
• Supplements mixed equipage environments during the ADS-B transition.
• Does not relieve pilots of “see and avoid” responsibility.

TIS-B is especially valuable in busy terminal areas and for general aviation.

Automatic Dependent Surveillance–Rebroadcast (ADS-R)

ADS-R bridges the gap between the two main ADS-B frequencies (1090ES and 978 MHz UAT), allowing aircraft on different links to “see” each other.

• Rebroadcasts received ADS-B data from one link to the other.
• Ensures a comprehensive traffic picture for all equipped aircraft.
• Fully automated and requires no pilot action.
• Coverage is “client-based,” centered on eligible aircraft.

ADS-R supports seamless integration in mixed-fleet and mixed-technology environments.

Key Information Types in FIS

METAR and TAF

• METAR: Hourly, standardized reports of current weather at airports (wind, visibility, precipitation, clouds, temperature, pressure).
• TAF: Forecasts of expected conditions within 5nm of airports, typically valid for 24–30 hours.

Both are critical for flight planning, decision-making, and regulatory compliance. Delivered via FIS, ATIS, and digital platforms.

NOTAM (Notice to Air Missions)

NOTAMs inform pilots of temporary or permanent changes that may influence flight safety, such as:

• Runway closures
• Airspace restrictions
• Navigation aid outages
• Hazards (obstacles, military activity)

Pilots must review current NOTAMs before and during flight. ICAO Annex 15 and Doc 8126 provide NOTAM standards.

AIRMET and SIGMET

• AIRMET: Advisories for less severe weather (e.g., moderate turbulence, icing, IFR conditions).
• SIGMET: Advisories for significant weather hazards (e.g., severe turbulence, volcanic ash, thunderstorms).

Both are disseminated through FIS and are essential for in-flight safety.

Enabling Technologies

Universal Access Transceiver (UAT)

• Operates at 978 MHz.
• Designed for US general aviation; supports both ADS-B Out and In.
• Enables reception of FIS-B, TIS-B, and ADS-R.
• Not accepted for international operations (use 1090ES instead).

UAT offers affordable access to digital information for lower-altitude aircraft.

1090ES (1090 MHz Extended Squitter)

• Standard for commercial, high-altitude, and international airspace.
• Uses Mode S transponder with extended message formats.
• Receives TIS-B and ADS-R, but not FIS-B.

1090ES underpins global airspace surveillance infrastructure.

The Role of FIS in Modern Aviation

FIS is vital for all phases of flight—from preflight planning to approach and landing. Its evolution from voice-based to digital delivery has:

• Improved the speed and accuracy of information dissemination
• Reduced radio workload and the risk of miscommunication
• Provided pilots with richer, more actionable data (graphical weather, real-time traffic)
• Supported regulatory compliance and operational efficiency

The integration of FIS with automation, data link, and advanced surveillance forms the backbone of the next-generation air traffic system.

Summary Table: FIS Components and Technologies

Frequently Used Terms

• FIS-B: Flight Information Service–Broadcast
• TIS-B: Traffic Information Service–Broadcast
• ADS-B: Automatic Dependent Surveillance–Broadcast
• ADS-R: Automatic Dependent Surveillance–Rebroadcast
• UAT: Universal Access Transceiver (978 MHz)
• 1090ES: 1090 MHz Extended Squitter
• METAR: Meteorological Aerodrome Report
• TAF: Terminal Aerodrome Forecast
• NOTAM: Notice to Air Missions
• AIRMET/SIGMET: Weather advisories

Conclusion

Flight Information Service (FIS) is a cornerstone of aviation safety and operational efficiency. From its roots as a voice-only support service in uncontrolled airspace, FIS has evolved into a sophisticated suite of digital tools that deliver real-time, actionable data directly to pilots’ cockpits. With advances in ADS-B, FIS-B, and data link communications, pilots can now access graphical weather, up-to-the-minute NOTAMs, and comprehensive traffic awareness, empowering better decision-making in all phases of flight.

As the aviation world continues to modernize, FIS will play an even greater role in supporting safe, efficient, and informed operations—especially as airspace becomes busier and more complex.