The agreed ICAO Aerodrome SARPs appeared in Annex 14 in 2016
with additional guidance found in the PANS Aerodromes Doc 9981 and Circular 355.
The GRF is a major step forward in cross functional (Aerodromes, ATM and Flight
operations) harmonisation that enables runway surface conditions to be reported
in a standardized manner, such that flight crew can accurately determine
aircraft take-off and landing performance. The GRF also incorporates the
potential to communicate actual runway surface conditions to flight crew in
real time and in terms that directly relate to aircraft performance data.
The GRF can be used in all climates and provides a means for
aerodrome operators to correctly assess runway surface conditions including
rapidly changing conditions such as those experienced during winter or in
tropical climates.
UK aerodromes will already be familiar with runway condition
assessments by each third of the runway. The GRF comprises an assessment by
airport operations staff using a Runway Condition
Assessment Matrix (RCAM) and the consequent assignment of a Runway Condition Code (RWYCC) rangingfrom 6 to 0, see below. This code is
complemented by a description of the surface contaminant based on type, depth and % coverage for
each third of the runway. The code is based on the effect of the runway
conditions on aircraft braking.
The outcome of the assessment and associated RWYCC are transmitted
using a Runway Condition Report (RCR)
forwarded to air traffic services and the aeronautical information services for
dissemination to pilots. The pilots will use the RWYCC to determine their
aircraft’s performance by correlating the code with performance data provided
by their aircraft’s manufacturer. This will help pilots to correctly carry out
their landing and take-off performance calculations for wet or contaminated
runways.
Runway condition assessment matrix (RCAM)
Source: ICAO Document 9981 PANS -ADR
Assessment criteria
|
Downgrade assessment criteria
|
Runway condition code
|
Runway surface description
|
Aeroplane deceleration or directional control observation
|
Pilot report of runway braking action
|
6 |
|
- |
- |
5 |
- Frost
- Wet (The runway surface is covered by any visible dampness or water up to and including 3mm depth)
Up to and including 3mm depth: |
Braking deceleration is normal for the wheel braking effort applied AND directional control is normal |
Good |
4 |
-15°C and lower outside air temperature:
|
Braking deceleration OR directional control is between Good and Medium |
Good to Medium |
3 |
- Wet ('slippery wet' runway)
- Dry snow or wet snow (any depth) on top of compacted snow
More than 3mm depth: Higher than -15°C outside air temperature¹: |
Braking deceleration is noticeably reduced for the wheel braking effort applied OR directional control is noticeably reduced |
Medium |
2 |
More than 3mm depth of water or slush:
|
Braking deceleration OR directional control is between Medium and Poor |
Medium to Poor |
1 |
|
Braking deceleration is significantly reduced for the wheel braking effort applied OR directional control is significantly reduced |
Poor |
0 |
- Wet ice²
- Water on top of compacted snow²
- Dry snow or wet snow on top of ice²
|
Braking deceleration is minimal to non-existent for the wheel braking effort applied OR directional control is uncertain |
Less than Poor |
¹ Runway surface temperature should preferably be used where available
² The aerodrome operator may assign a higher runway condition code (but no higher than code 3) for each third of the runway, provided the procedure in 1.1.3.15 is followed.
The GRF also allows pilots to report their own observations
of runway conditions, thereby confirming the RWYCC or providing an alert to any
changing conditions. The other key attributes to the GRF are its relative
simplicity of use and the fact that it is globally applicable.
Important changes have also been made to ICAO Annex 15 with
the inclusion of a new Snowtam format also to be used from November 2020.
Whilst November 2020 may seem a long way off it is important
that both certificated and licensed aerodromes become familiar with the
material in both ICAO Annex 14 and PANS Aerodromes. The latter has 18 pages of
excellent guidance material on all the elements of the new GRF under Part II –
Aerodrome Operational Management. It is also planned that your aerodrome
inspectors will organise briefing sessions in the run up to the applicability date.
CAA will also take the opportunity to publicise the GRF through industry
meetings and conferences.
Aerodrome operators however may wish to run parallel trials
this coming winter. This would enable airport operations staff to continue with
the current reporting methodology but see how they would report the runway
surface condition in the new GRF format. CAA would encourage aerodrome
operators to do this as it will contribute greatly to the full introduction
next year. If you do intend to run a parallel trial, please let your aerodrome
inspector know so that any lessons learned can be exchanged. For those aerodromes that are interested,
Airports Council International (ACI) have developed an online computer-based
training package which you might find useful in training your operation
staff.