Global Reporting Format (GRF) in Automatic Terminal Information Service (ATIS) Messages

Runway surface conditions have a critical impact on aircraft takeoff and landing performance. In recent years, international aviation authorities have introduced the Global Reporting Format (GRF) for runway conditions as a standardized method to assess and report these conditions to flight crews. The GRF was developed by the International Civil Aviation Organization (ICAO) to reduce the risk of runway excursions (overshoots or overruns) by ensuring pilots, air traffic controllers, and airport operators share a common understanding of runway surface state. This new format, applicable worldwide since November 2021, has important implications for how information is disseminated via the Automatic Terminal Information Service (ATIS) and other channels.

ATIS broadcasts continuous aerodrome information to aircraft, and with GRF integration, it now includes standardized runway condition reports. This article provides a detailed look at what GRF is, how it is used in ATIS messages, and its impact on Air Traffic Control (ATC) and Air Traffic Management (ATM), with reference to ICAO regulations and an example of an ATIS system (ANSART’s Integrated ATIS/D-ATIS) that meets these requirements.

Understanding the Global Reporting Format (GRF)

Global Reporting Format (GRF) is an ICAO-standard methodology for assessing and reporting runway surface conditions in a harmonized way. Under GRF, a trained observer at the aerodrome (usually operations or maintenance personnel) evaluates the runway whenever it is contaminated by water, snow, slush, ice or frost (any condition other than dry). The observer uses a globally standardized Runway Condition Assessment Matrix (RCAM) to assign a Runway Condition Code (RWYCC) to each third of the runway, corresponding to the level of braking action expected. Each runway third (touchdown, midpoint, stop-end) gets a code from 0 to 6, where 6 indicates a dry runway (good braking) and 0 indicates extremely poor conditions (e.g. wet ice, almost no braking). These codes are complemented by a description of the type of contaminant on that portion of runway, its depth, and the percentage of coverage, using standardized terms and units. The result of this assessment is the Runway Condition Report (RCR).

The RCR is then disseminated to pilots through multiple channels. ICAO has mandated that runway condition information be promulgated via a special NOTAM called SNOWTAM (for textual distribution through Aeronautical Information Services) and via ATIS broadcasts, and additionally by voice from controllers if necessary. This ensures the information reaches flight crews in a timely manner. A key benefit of GRF is that it aligns with aircraft performance data: flight crews can directly correlate the reported runway condition codes with performance charts from the aircraft manufacturer to calculate landing and takeoff parameters. In essence, GRF creates a common language and format for runway state that is used globally, improving safety by reducing ambiguity. Notably, GRF is used not only for winter operations; wet runways in rainy conditions are also reported using this format, so the system is applicable year-round.

International Regulatory Context for GRF

The introduction of GRF came through a series of ICAO amendments and guidance materials that set the international regulatory context. ICAO Annex 14 (Aerodromes) and Annex 15 (Aeronautical Information Services) were updated to support the new reporting system, and procedures were detailed in documents such as the ICAO PANS-ATM (Procedures for Air Navigation Services – Air Traffic Management, Doc 4444) and PANS-AIM (Aeronautical Information Management, Doc 10066 for SNOWTAM format). The applicability date for the global implementation of GRF was 4 November 2021 (after a pandemic-related postponement from the original 5 November 2020 date). For example, ICAO Annex 15 Amendment 39B introduced a new SNOWTAM format aligned with GRF and became applicable on that date. This meant all ICAO member states were expected to have their aerodrome operators and air navigation service providers ready to use the new format by that time.

In terms of ATIS-specific guidance, ICAO has provided clear direction on how ATIS messages should include runway condition information under GRF. Annex 11 (Air Traffic Services) contains provisions on ATIS broadcasts, and the PANS-ATM (Doc 4444) §6.6.1 outlines the ordering and content of ATIS messages including when runway surface condition reports should be inserted. Additionally, ICAO Circular 355 (AN/211) published in 2019 gives more detailed guidance on incorporating the Runway Condition Report into ATIS and radio transmissions. According to these standards, whenever the runway is not dry (i.e., RWYCC is 5 or below), the ATIS must convey the runway condition information to pilots in a structured format, in addition to the usual meteorological and operational data. ICAO’s guidance specifies that the ATIS should include both a performance section (critical details affecting aircraft performance) and a situational awareness section (additional contextual information) related to runway condition. The following elements are required in an ATIS broadcast when reporting runway conditions under GRF:

• Runway in Use and Time of Observation: Identify the runway for which the report applies (the runway currently in use) and the time the runway condition was observed (e.g., “runway 24 condition report at 0230”).

• Runway Condition Codes: State the RWYCC for each third of that runway in the landing direction. These are given as three numbers (one per portion) or a single code if only one portion is affected. For example, “runway condition codes 5, 2, 4” indicates the touchdown third is code 5, midpoint third code 2, and rollout third code 4. If a code is downgraded or upgraded by the airport operator from the automatically suggested value, the word “downgraded” or “upgraded” is included for clarity.

• Contaminant Type, Depth, Coverage: Provide a plain-language description of the surface contaminant on each runway segment, including its type (e.g. wet, slush, dry snow, wet snow, ice), the depth (for loose contaminants like snow/slush, in millimeters), and the percentage coverage of that third. For example: “first part 100 percent wet; second part 50 percent 4 millimeters slush; third part 50 percent 3 millimeters slush”. Terms like "millimeter" and "percent" are spoken in full for clarity, and numeric values are normally pronounced as whole numbers.

• Runway Width (if reduced): If the cleared or usable width of the runway is less than the published full width, state the width to which the runway condition report applies (e.g., “runway width 35 meters” if parts of the runway are not cleared).

• Reduced Length (if applicable): If any portion of the runway length is not available (e.g., closure of a section), mention the available length or that a portion is closed, although typically a closed portion would be handled via NOTAM rather than ATIS.

• Situational Awareness Items: Include any other pertinent information that could affect braking or safety: for example, snowbanks along the runway (if significant, state their distance from runway centerline and height), drifting snow or loose sand on the runway, and the condition of taxiways or aprons if they are “poor” (i.e., very slippery). For instance, an ATIS might add, “Snow bank left 20 meters from centreline”, and “Taxiway B poor, apron north poor” to alert pilots of challenging conditions on exit taxiways or apron areas. Any other essential remarks can be included in short plain language.

These requirements are derived from ICAO’s standard SNOWTAM format and are mirrored in ATIS to ensure consistency. By following this structured content order (runway, codes, descriptions, other info) as defined in ICAO PANS-ATM and related guidance, ATIS broadcasts around the world deliver uniform information. This international regulatory framework ensures that a pilot landing in any country will receive runway condition information in a familiar format, thereby enhancing both safety and efficiency in global air traffic management.

GRF in ATIS Messages: Format and Examples

Integrating the Global Reporting Format into Automatic Terminal Information Service (ATIS) messages has required standardized phraseology so that flight crews can readily understand the Runway Condition Report. ATIS messages are typically delivered via automated voice broadcast on a specific frequency and often also via D-ATIS (digital text transmission to aircraft or ACARS). When GRF information is included, it is crucial that the ATIS message is clear and unambiguous. ICAO has published example phraseology demonstrating how GRF is incorporated into ATIS. For instance, an ICAO ATIS training flyer provides the following sample ATIS excerpt (for an imaginary airport "Donlon"):

DONLON INFORMATION OSCAR AT 0245 – ILS approach, runway in use 24. Runway 24 condition report at 0230: runway condition codes 5, 2, 4, downgraded. First part 100 percent wet; second part 50 percent 4 millimeters slush; third part 50 percent 3 millimeters slush. Runway width 35 meters. Snow bank left 20 meters from centreline. Taxiway B poor. Apron North poor. Transition level 60. METAR Donlon 0220: wind 350 degrees 8 knots variable between 320 and 060 degrees, visibility 10 kilometers or more, scattered 3000 feet, temperature minus 1, dewpoint minus 3, QNH 1014 hectopascals, NOSIG.

In this example, the ATIS message (Information Oscar) includes a runway condition report for Runway 24. It clearly indicates the time of the observation (0230), the RWYCC for each third (5, 2, 4) including that a code was “downgraded” by the airport operator from what the matrix might have suggested, and describes the contaminant on each portion (wet in the first third, slush of certain depth on the second and third parts). It also notes the runway width to which this report applies (35 m, implying maybe the full width or a reduced width) and additional situational information like snow banks and poor braking conditions on a taxiway and apron. All of this is given before the routine METAR weather information. This ordering conforms to the recommended ATIS structure in ICAO documents: first the operational and surface condition information, then the meteorological data.

To ensure clarity when delivering GRF content in ATIS, ICAO’s phraseology guidance suggests a few important practices: using the phrase “runway condition report” to preface the GRF information so pilots know the following content pertains to runway state, including the word “at” before the time (e.g., “at 0230”), and using full words for units like “millimeters” and terms like “percent” to avoid confusion. The runway condition codes are spoken as a plural (e.g., “runway condition codes 5, 2, 4” rather than singular) to make clear that multiple values (one per runway segment) are being given. Interestingly, the terms “coverage,” “depth,” and “contaminant” themselves need not be spoken; the values and units (e.g., “50 percent 4 millimeters slush”) are sufficient to convey the necessary information. This standardized phrasing helps flight crews quickly extract the needed details from an ATIS broadcast that may be packed with information.

By incorporating the GRF in this manner, the ATIS becomes a powerful tool to disseminate critical runway safety information without burdening pilots and controllers with lengthy voice exchanges. Pilots can receive the latest runway condition as soon as they tune in the ATIS, and they are alerted to any contamination or slipperiness that could affect landing or takeoff. The example above illustrates how ATIS essentially mirrors the SNOWTAM content in a spoken format, thereby reinforcing the information through multiple channels (text and voice). This dual availability (ATIS and SNOWTAM) is especially valuable, as SNOWTAMs are usually delivered to airline dispatchers or via pre-flight information bulletins, whereas ATIS gives a last-minute update while the aircraft is nearing the airport.

Impact on Air Traffic Control (ATC) Operations

The integration of GRF into ATIS and information services has a significant impact on Air Traffic Control (ATC) operations, primarily in a positive way. One of the immediate benefits is the reduction of controller workload for routine communications. Prior to GRF implementation, when runway conditions were poor (e.g., snow, ice, or significant water), air traffic controllers or aerodrome flight information service officers often had to broadcast braking action reports or detailed runway surface descriptions to each arriving aircraft. With a properly configured ATIS that includes the GRF-based runway condition report, this information is automatically provided to all aircraft, freeing controllers from repetitively transmitting the same details. ICAO notes that ATIS “presents a very important means of transmitting information, relieving operational personnel from the routine duty of transmitting runway conditions and other relevant information to the flight crew”. In other words, controllers can focus on active control tasks while the system handles the dissemination of surface conditions.

From an ATC procedures standpoint, the introduction of GRF did not fundamentally alter how controllers manage traffic, but it did change how certain information is formatted and delivered. Controllers must ensure that the ATIS is updated promptly whenever a new runway condition report is received (for example, when the airport operations staff assesses a change in runway conditions and issues an updated RCR and SNOWTAM). In fast-changing weather, this could mean more frequent ATIS updates than before. Controllers also need to be aware of the standardized terminology so that if pilots ask questions or if they must deliver the information via radio (e.g., if an aircraft cannot receive the ATIS), they use the correct phrases and format.

Initial implementation of GRF worldwide required training and familiarization for ATC personnel. Not only did controllers need to understand the new RWYCC scale and terminology, but they also had to adapt to minor changes in ATIS content order. According to an EASA safety bulletin, GRF did not change fundamental working practices for ATC, but training was considered necessary to learn “the new way of reporting” runway conditions. This included understanding how to read a SNOWTAM in the new format and how to convey it correctly over ATIS or voice. For example, in some regions, controllers had to get used to giving runway condition codes instead of (or in addition to) the older descriptions of braking action (such as "good, medium, poor"). Now, a pilot report of braking action “medium” might correlate with certain RWYCC values, and controllers/AIS officers ensure that any pilot-reported downgrade or upgrade is incorporated (hence the use of terms like “downgraded” in the ATIS if applicable).

Overall, from an ATC perspective, GRF integration improves situational awareness and communication efficiency. It provides a standardized checklist of what to include in ATIS when runway conditions are not ideal, ensuring no critical detail is omitted (such as a significant snowbank or a partially closed taxiway). Controllers benefit from this structured format because it reduces ambiguity – for instance, a RWYCC of 2 automatically conveys a certain expected braking performance that is universally understood, whereas previously terms like "poor braking action" could be somewhat subjective. This common understanding helps in decision-making, such as whether to increase spacing for landing aircraft or whether to suggest a braking action check by a preceding aircraft. In summary, GRF in ATIS enhances safety while streamlining ATC communications.

Implications for Air Traffic Management (ATM)

On a broader scale, the implementation of the Global Reporting Format has important implications for Air Traffic Management (ATM) as a whole. ATM encompasses the integrated management of air traffic and airspace, including air traffic flow, capacity, and overall safety of operations. By standardizing runway condition reporting across the globe, GRF contributes to greater predictability and consistency in ATM. Pilots, dispatchers, and controllers all refer to the same format of information, which reduces the chance of misinterpretation. For instance, an airline dispatcher in one country and an air traffic flow manager in another will both understand a SNOWTAM/ATIS report of “RWYCC 3/3/2” in the same way, leading to coordinated decisions (like whether certain aircraft should divert, or whether additional de-icing or braking considerations are needed).

A major ATM impact of GRF is enhanced safety management. Runway excursions have been a top safety risk category for many years, and analyses showed that inconsistent reporting of runway surface conditions was a contributing factor. By harmonizing the reporting, GRF directly addresses this risk. ICAO’s introduction of GRF was accompanied by guidance on Management of Change, urging states to assess any hazards introduced by the new system and ensure all parties (aerodrome operators, ANSPs, airlines) were ready. This global safety initiative means that ATM at the national and local level had to align with the new standards. Many aviation authorities (for example, EASA in Europe, FAA in the US with similar concepts, etc.) synchronized their regulations to ICAO’s provisions, requiring all airports to use the new format by the effective date. This coordinated rollout across ATM systems was essential to maintain consistency – non-implementation by even a few major airports could have led to confusion.

Another implication is on technology and systems within ATM. Legacy ATIS or information management systems needed upgrades or replacements to handle the new format (for example, new fields for runway condition codes in digital ATIS messages, or text-to-speech systems updated with new lexicon like "runway condition code five"). ATM systems that feed information to pilots, like electronic flight bags or data link services, also had to be checked for compliance with the new SNOWTAM format (which is more structured than the old one). In many cases, the adoption of GRF was an opportunity for airports and ANSPs to modernize their ATIS and meteorological information systems, ensuring they can automatically process inputs from runway sensors or inspection reports into the standardized output. Modern ATM strives for automation and data-driven decision support, and GRF fits well into this trend by providing quantitative codes that can be used in decision algorithms (for example, a system could automatically suggest reduced landing rates when a low RWYCC is reported, or alert if conditions warrant closure).

From an airline and pilot perspective (which is a part of the ATM ecosystem), having GRF information on ATIS allows better flight preparation and real-time adjustments. A pilot who hears an ATIS with a runway condition code of 2 for the touchdown zone knows to expect very limited braking, which might prompt a go-around decision or diversion if performance calculations show insufficient margin. In turn, this can affect ATM by, for instance, increasing spacing (if aircraft need to roll longer on landing) or changing runway use strategies at a multi-runway airport (if one runway has a much better condition than another).

In summary, GRF’s integration into ATIS and information dissemination is a safety enhancement with positive ripple effects on air traffic management. It exemplifies how standardization across international aviation can improve operational efficiency and safety. By using common codes and terms, it reduces communication errors and allows all stakeholders in ATM to make more informed decisions in adverse runway conditions.

ANSART’s Integrated ATIS/D-ATIS System and GRF Compliance

Implementing GRF in daily operations often requires capable technology solutions. One example is ANSART’s Integrated ATIS/D-ATIS System, which is designed to automate aerodrome information broadcasts and is built to meet modern requirements, including the Global Reporting Format. This system provides continuous ATIS and D-ATIS (Data-link ATIS) services, ensuring that both voice broadcasts and digital messages contain up-to-date meteorological and operational information for aircraft. Crucially, it supports the inclusion of runway condition reports in compliance with GRF standards. The system handles automated processing of various aeronautical messages such as METAR, SPECI, SIGMET, and specifically GRF SNOWTAM messages. This means when an airport operations team issues a new Runway Condition Report, the system can ingest the corresponding SNOWTAM data and incorporate the key details automatically into the next ATIS transmission.

To address GRF requirements, an ATIS system must ensure information is both timely and formatted correctly. The ANSART system includes features like “constant format control” which ensures that data inputs (e.g., a SNOWTAM message) are converted into the ATIS message consistently without human error. For example, if the SNOWTAM indicates RWY 15 has codes 5/5/2 with certain contaminant descriptions, the system’s text-to-speech engine or message compiler will assemble the ATIS announcement exactly as per ICAO phraseology guidelines, including all relevant parts of the RCR. This reduces the chance of a controller or information officer accidentally omitting a detail during manual input. By automating these tasks, the system reduces controller workload and enhances safety. Controllers remain in a supervisory role, verifying the information, but do not have to record new ATIS messages by voice each time conditions change – the system can generate the new message and even broadcast it simultaneously on multiple channels (radio frequency, telephone, and data-link).

Another aspect of GRF compliance is reliability and redundancy. Runway condition information is time-sensitive and critical, so an ATIS system should have high availability. The ANSART Integrated ATIS/D-ATIS provides “hot backup” servers and full redundancy, meaning even if one server fails, the ATIS broadcast continues uninterrupted on a backup. This is important during bad weather events when runway conditions may deteriorate quickly; the last thing an airport needs is the ATIS going down when pilots most need that information. The system is also designed in line with international standards and recommendations (including ICAO and European standards), ensuring it “meets all requirements for ATIS and VOLMET broadcasts,” which implicitly covers the GRF reporting elements.

In practice, a GRF-compliant ATIS system like ANSART’s would work as follows: The moment the airport’s runway inspection team inputs a new runway condition (say, via an interface to the Airport Operations database or directly into the ATIS system), the system updates the ATIS message. It might generate a new ATIS code (information letter) if needed and broadcast something like in the earlier example, e.g., “Runway 18 condition report at 15:30 Zulu…” with the new codes and descriptions. Pilots tuning in will immediately get the latest runway state. If the airport has a data-link service, the same information is sent to the cockpit displays as D-ATIS. This seamless integration ensures compliance with GRF without adding delays or errors, showcasing how technology supports the GRF initiative.

It is worth noting that while ANSART’s system is highlighted here as an example, many ANSPs and airports worldwide have implemented or are implementing similar integrated ATIS solutions. The key is that any such system must be robust, standard-compliant, and capable of handling the specific data formats (like the new SNOWTAM fields) that GRF entails. By doing so, these systems help operationalize the GRF concept, turning ICAO’s standards into real-world practice that pilots and controllers can depend on.

Conclusion

The introduction of the Global Reporting Format in ATIS messages marks a significant advancement in how critical runway information is shared in aviation. GRF provides a clear, standardized framework for reporting runway surface conditions, replacing disparate methods with a common language understood by pilots, controllers, and airport operators worldwide. Through ICAO’s leadership and regulations, including updates to annexes and guidance material, GRF has been integrated into the fabric of air traffic communications – most visibly through ATIS broadcasts and SNOWTAMs that now deliver uniform runway condition codes and descriptions.

For professionals in air traffic management and control, GRF in ATIS means greater confidence that vital information will not be lost in translation. Controllers benefit from reduced workload on routine communications and can trust that pilots have an accurate picture of the runway state before critical phases of flight. Air traffic management as a whole gains from the improved safety margins and efficiency; standardized information leads to more predictable operations and aids in decision-making during adverse conditions. The example of ANSART’s Integrated ATIS/D-ATIS system illustrates how industry solutions are aligning with these requirements, ensuring that technology is in place to automatically disseminate GRF information reliably and accurately.

In essence, the GRF’s incorporation into ATIS exemplifies the aviation community’s proactive approach to safety and efficiency. It is a response to lessons learned from past incidents, put into practice through international collaboration. As the system continues to mature, ongoing feedback (for example, from flight crews’ reports of braking action or from ATC units during winter operations) will help refine the processes. However, even at this stage, there is a clear consensus that GRF in ATIS messages enhances runway safety and provides a more unified approach to air traffic management, benefiting all stakeholders in the aviation system.

Sources:

• International Civil Aviation Organization (ICAO) – Global Reporting Format documentation and circulars for runway surface condition reporting.

• ICAO Annex 15 & PANS-AIM – Amendment introducing the new SNOWTAM format aligned with GRF.

• ICAO PANS-ATM (Doc 4444) & Circular 355 – Provisions detailing ATIS message content and structure for runway condition reports.

• SKYbrary Aviation Safety – Explanation of Runway Condition Code system and RCAM.

• EASA Together4Safety Webinar Q&A – Impacts of GRF implementation on ATC/ATM and training needs.

• ANSART B.V. – Integrated ATIS/D-ATIS System description and features addressing GRF and automated SNOWTAM processing.