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Global Reporting Format RWYCC Calculator

This Global Reporting Format (GRF) Runway Condition Code (RWYCC) calculator allows runway inspectors to calculate a preliminary RWYCC for training purposes. A full-featured version of this calculator is built into the Snowbird runway surface condition reporting software.

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Last updated on March 24, 2021.
Note: this calculator is intended for training purposes, and no warranty is provided or implied.
Please submit any feedback via our contact form.

Snowbird GRF app screenshot

Related Resource: What is the Global Reporting Format (GRF)?

About the Calculator

ICAO's Global Reporting Format (GRF) [1] for runway surface condition reporting – which has been be applicable worldwide as of November 4, 2021 [2] – brings with it many changes related to how airport movement surfaces are to be assessed and reported on, but probably the most notable of these is the Runway Condition Code (RWYCC).

Described by ICAO Circular 355 (Assessment, Measurement and Reporting of Runway Surface Conditions) [3], the Runway Condition Code is a value between 0 and 6 used by runway inspectors to describe the surface conditions of that runway (or portion of that runway). RWYCC calculation is a deterministic process which uses the conditions of a particular runway portion as inputs.

The Runway Condition Assessment Matrix (RCAM) is an aid to be used by runway inspectors to arrive at the correct RWYCC value, based on objective measurements and rules. Carefully following the RCAM will give the runway inspector the correct preliminary RWYCC value for that runway portion.

Due to the complex set of rules that is used to determine the RWYCC from runway surface conditions and the RCAM, we have developed a GRF-compliant Runway Condition Code Calculator, which is built right into our Snowbird runway reporting software. Learn more on our homepage, and contact us for a free demo today.

We have provided a portion of this calculator (used to calculate a preliminary RWYCC for a single runway third) for training purposes below.

Additional Notes

  1. This calculator only calculates the preliminary RWYCC for a single runway portion (third). For runways with an active NOTAM of "slippery when wet", runway inspectors must take into account the RWYCC of each third of the runway in order to arrive at the correct RWYCC values.
  2. The calculator calculates only the preliminary RWYCC value. It is then up to the runway inspector to upgrade or downgrade these values to arrive at the final RWYCC (described in more detail below).
  3. This calculator is meant to be used for paved runways only.
  4. The "Slush Over Ice" condition is used by Canadian airports, but not part of the ICAO GRF standard.

Upgrading or Downgrading the RWYCC

Given the preliminary value, the runway inspector may then choose to upgrade or downgrade the final RWYCC.

Typically, upgrades and downgrades may be applicable due to:

  1. Friction measurements on the runway not corresponding to the calculated preliminary RWYCC value.
  2. The runway inspector's vehicle deceleration or directional control observation not aligning with the preliminary RWYCC (as specified by the RCAM).
  3. Pilot reports (PIREPs) not aligning with the calculated preliminary RWYCC.

See ICAO Circular 355 [3] for more details.

REFERENCES

[1] https://www.icao.int/safety/Pages/GRF.aspx

[2] Note that each country's regulator may set their own implementation date. For example, the implementation date for GRF in Canada was August 12th, 2021 (See Transport Canada Advisory Circular No. 300-019).

[3] https://store.icao.int/en/assessment-measurement-and-reporting-of-runway-surface-conditions-cir-355