When a runway is wet, slushy or snow-covered, the question a pilot needs answered is simple: how much braking and directional control can I count on? The Global Reporting Format is the worldwide answer to that question, written in one language every controller, dispatcher and pilot can read the same way.
This is general educational information, not operational, legal, or regulatory advice. Rules differ by authority and change over time. Always verify against current official sources and follow your operator's approved procedures.
One format, worldwide
The Global Reporting Format (GRF) is the harmonised method for assessing and reporting the surface condition of a runway, applicable worldwide since 4 November 2021. It is set out in ICAO Doc 9981 (PANS-Aerodromes) and Annex 14, and the same scheme is used in the United States as the FAA's RCAM and in the United Kingdom under CAA guidance.
Before the GRF, runway-state reporting was a patchwork of friction readings and local braking descriptions that did not always transfer cleanly between countries or correlate well with how an aircraft actually stopped. The GRF replaced that with a single chain: assess the contaminant, read a code from a matrix, and report it in a fixed form that everyone decodes the same way.
The runway condition code: 6 to 0
At the heart of the format is the runway condition code (RWYCC), a single digit from 6 down to 0. Most of the values carry a plain braking-action word, as SKYbrary and the source documents set out:
- 6: a dry runway. This is the one code with no braking-action word attached to it in either the ICAO or the FAA matrix, so do not go looking for one and do not invent "excellent".
- 5: good.
- 4: good to medium.
- 3: medium.
- 2: medium to poor.
- 1: poor.
- 0: the bottom of the scale, and the one place the two matrices use different words. ICAO calls it less than poor; the FAA's RCAM calls it nil. The meaning is the same, and it is the meaning that matters: braking is effectively unusable.
A higher number is a better surface. A 6 is reported for a dry runway; the lower the number, the less braking and directional control the surface offers.
The assessment matrix (RCAM)
The code does not come from a friction reading. It comes from the Runway Condition Assessment Matrix (RCAM), a table that maps the type of contaminant (for example frost, wet, slush, dry snow, compacted snow or ice) and its depth to a starting condition code and the matching braking-action word. The assessor then checks that against other cues, including the outside air temperature and, importantly, pilot reports of braking action: a special air-report of braking worse than the matrix implies can downgrade the code.
This is the key idea of the GRF. The aerodrome describes what is physically on the runway, the matrix turns that into a code, and the code is the same currency the flight crew use to look up their aircraft's performance.
How the report is built
A GRF report describes the runway in three equal-length thirds, and gives, for each third, its condition code, the contaminant type, the depth in millimetres, and the percentage of that third the contaminant covers.
Which way round the thirds run depends on who wrote the report, and this is the single easiest thing to get wrong. Under ICAO, and so in a SNOWTAM, the thirds are listed in the direction of the lower runway designator, which means a report for runway 09/27 is read in the 09 direction whichever end you land on: land on 27 and you meet the reported thirds in reverse. Under the FAA, a US FICON NOTAM names a single runway designator, the one that was assessed, and lists its thirds in that landing direction, first third first. So a US FICON for RWY 27 already reads in the direction you are landing, and reversing it in your head would be exactly wrong.
The habit that survives both systems is to read the designator at the top of the report and ask which end it describes, rather than assuming either rule.
The full report has two parts:
- The aeroplane performance section: the per-third codes, contaminant, depth and coverage, plus any reduced declared distance. This is the part that feeds landing and take-off performance.
- The situational awareness section: plain-language detail such as drifting snow, snow banks, a reduced runway width, or the state of taxiways and aprons.
The report is distributed in the SNOWTAM format and can also be passed by ATIS or by voice, so the same coded assessment reaches you whether you are reading a briefing pack or listening on the radio.
A worked example
Suppose an ICAO report (a SNOWTAM) gives runway 09/27 the codes 5/5/3, with the first two thirds wet and the final third covered by 5 mm of wet snow over half its area.
Reading it through:
- Under ICAO the thirds are listed in the direction of the lower designator, so this report reads in the 09 direction and the leading 5 is the first third you cross when landing on 09.
- 5/5/3 means the first two thirds are good and the final third is medium.
- The final third is the one to plan around: 5 mm of wet snow over 50 per cent of it has pulled that third down to a 3.
- Land on runway 27 instead and you meet the thirds in reverse, so the medium third is now first, near the touchdown zone.
Now take the same runway in the United States. A FICON NOTAM reading RWY 27 3/5/5 has already been written in the 27 landing direction, so the medium third really is the first one you cross, and there is nothing to reverse. Same physical runway, same contaminant, two reports that look like each other's mirror image because the two systems anchor the thirds differently.
The figures are awareness. The stopping numbers come from your aircraft's approved performance data for that contaminant and code.
Common pitfalls
- Assuming one rule for the direction of the thirds. In an ICAO report they follow the lower runway designator, so on the reciprocal runway the order is reversed; in a US FICON they are already in the assessed landing direction, so reversing them puts the worst third in the wrong place. Read the designator on the report first.
- A good first third is not a good runway. The worst third is usually what matters most, and where it sits relative to your touchdown and stop changes with the runway in use.
- Expecting a braking-action word for a 6. There is none; 6 simply means a dry runway. And at the other end of the scale, ICAO's "less than poor" and the FAA's "nil" are the same code 0.
- The code is a starting point, not a stopping distance. Pair it with your aircraft's contaminated-runway performance data, and treat a worse pilot braking-action report as the more current picture.
In Pilot EFB
Pilot EFB brings the NOTAMs for your aerodrome, including runway-state notices, into the briefing, shown as the raw text alongside a decoded view so a runway-condition report is in front of you rather than buried. A briefing you have already pulled stays readable offline; fetching the latest runway state needs a connection. Pilot EFB is offline-first and is not a certified Electronic Flight Bag, so confirm the current report and apply your aircraft's approved performance data before you commit to a runway.