by TCCA GRF Implementation Team: Guy Héneault, Drew Dutton, Robert Kostecka, Cheryl Bugden, Aerodrome Standards, and Benoit Saulnier, Commercial Flight Standards
With the implementation of the Global Reporting Format (GRF)—the internationally-accepted method for reporting runway surface conditions—Canada has taken a major step towards improving flight safety.
Canadian implementation of GRF took place on August 12, 2021, approximately three months prior to the target date specified by the International Civil Aviation Organization (ICAO). There were compelling reasons that prompted ICAO to call for a standardized and improved method to report runway surface conditions.
At its heart, GRF is intended to help mitigate the hazards and risks associated with operations on runways that are wet or contaminated with water, slush, snow, compacted snow, frost, or ice. These hazards and risks are well known and have been thoroughly documented. In Canada, accidents during operations on wet or contaminated runways have included several Transport Category aircraft types, including the Airbus A340, Embraer 145, Boeing 727, and Boeing 737, as well as a variety of other aircraft. In view of these important safety issues, runway overruns have been on the Transportation Safety Board (TSB) Watchlist since 2010.
The origins of GRF can be found in the work of the Takeoff and Landing Performance Assessment Aviation Rulemaking Committee (TALPA ARC). After a Boeing 737-700 runway overrun accident at Chicago Midway Airport, which occurred on December 8, 2005 (Figure 1), the United States Federal Aviation Administration (FAA) convened the TALPA ARC. The goal of this committee was to consider safety issues associated with takeoff and landing on wet and contaminated runways. Participants included aircraft manufacturers, air operators, airport operators, industry associations (pilot associations, airport associations, etc.), the U.S. National Transportation Safety Board, as well as the US FAA, Transport Canada and other civil aviation authorities.
The TALPA ARC discovered significant gaps in the methods used for reporting runway surface conditions and the performance information used by flight crews. The TALPA ARC developed recommendations to address these shortcomings, which were delivered to the FAA in July 2009. These recommendations, which have collectively come to be known as “TALPA,” included the development of consistent terminology and runway assessment criteria, presented in a standardized format. Ultimately, the recommendations of the TALPA ARC—which the United States Federal Aviation Administration (U.S. FAA) incorporated into the US reporting system in 2016—served as the basis for the ICAO GRF.
The GRF, which is mandated by ICAO, incorporates many of the significant safety enhancements that resulted from the TALPA ARC. The ICAO guidance specifies several important characteristics for runway surface condition reports. These include:
- an agreed set of criteria used in a consistent manner for runway surface condition assessment, aeroplane (performance) certification and operational performance calculation;
- a unique runway condition code (RWYCC) linking the agreed set of criteria… and related to the braking action experienced and eventually reported by flight crews;
- reporting of contaminant type and depth that is relevant to take-off performance;
- a standardized common terminology and phraseology for the description of runway surface conditions that can be used by aerodrome operator inspection personnel, air traffic controllers, aircraft operators and flight crew; and
- globally-harmonized procedures for the establishment of the RWYCC with a built-in flexibility to allow for local variations to match the specific weather, infrastructure and other particular conditions.
The Canadian implementation of GRF meets the intent and important safety elements mandated by ICAO and will also provide some important enhancements that were necessary to improve safety and harmonize with the TALPA reporting format that has been in place in the United States since 2016. One of the main differences from the ICAO format is the ability to report two contaminants (per runway third; or for the entire runway, when reporting by full runway length). Reporting two contaminants:
- allows pilots and flight dispatchers to accurately determine the maximum allowable take-off weight—since the limiting contaminant is not the same for all aeroplanes; and
- harmonizes the reporting in North America, since the United States Field Condition NOTAM (FICON) also lists two contaminants.
One of the most important mitigations for the hazards and risks associated with operations on wet and contaminated runways is the usage of appropriate aeroplane performance information. Some aircraft types—typically large Transport Category aeroplanes—have manufacturer-produced performance data that is designed to account for wet and contaminated runway conditions and also aligns with the new GRF. When manufacturer-produced performance information or performance information from a third-party provider are not available, a landing distance factors (LDF) table—which also aligns with the new GRF—is provided in Advisory Circular (AC) 700-057 (Table 6).
The Canadian Runway Friction Index (CRFI) will continue to be reported. CRFI is a useful tool that enables airport and aerodrome operators to have an objective measure of runway friction and also serves to enhance pilots’ situational awareness. There are new regulations that require CRFI to be reported in thirds on longer runways that serve Commuter (Subpart 704) and Airline (Subpart 705) air operators. CRFI information now appears under the header “ADDN NON-GRF/TALPA INFO.” CRFI can be used for making time of arrival landing performance assessments by pilots and operators that do not utilize either:
- aeroplane performance information (manufacturer produced or developed by a third party) that accounts for contaminated runway conditions; or
- the (generic) Landing Distance Factor (LDF) table published in AC 700-057.
The hazards and risks of operations on wet and contaminated runways need to be clearly understood and effectively mitigated. The implementation of GRF in Canada is a major step forward that is intended to help accomplish this important goal.
Further information and guidance
Further information and guidance on GRF is available for flight operations personnel as well as airport and aerodrome operators:
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Note: The main body of the AC 700-057 provides background information as well as the essential information needed to read and understand the new Global Reporting Format (GRF) for runway surface conditions. The appendices provide more detailed explanations of various aspects of GRF as well as important safety information related to operations on wet and contaminated runways.
- AC 300-019—Global Reporting Format (GRF) for Runway Surface Conditions
Related articles on GRF as well as the hazards associated with wet and contaminated runways are planned for the Aviation Safety Letter.