Section 2, Chapter 7 - Runway Surface Conditions Flashcards
Who is responsible for assessing and disseminating aerodrome surface conditions?
The Aerodrome Operator is responsible for assessing and disseminating aerodrome surface conditions, though at some aerodromes, this responsibility may be delegated to the ATS unit.
What are the key elements for assessing and reporting runway surface conditions?
The key elements for assessing and reporting runway surface conditions are:
- Runway Condition Report (RCR): Used by pilots for performance calculations and situational awareness.
- Runway Condition Assessment Matrix (RCAM): Used by aerodrome personnel to determine Runway Condition Codes (RWYCC).
- Runway Condition Code (RWYCC): Determined by assessing:
1. Percentage of contamination coverage
2. Type of contaminant
3. Depth of contamination
4. Surface air temperature - Runway Surface Conditions: Standardized reporting terms.
- Runway Surface Condition Descriptors: Detailed descriptions for contamination types.
Note: GRF applies to paved runways; grass surfaces are reported differently.
When should reporting of runway surface conditions commence and continue?
Reporting should commence when a significant change in runway surface condition occurs due to water, snow, slush, ice, or frost, and continue until the runway is no longer contaminated. When the runway is no longer contaminated, a report stating the runway is wet or dry should be issued.
How should the presence of surface contaminants on a runway be reported by the ATS unit?
The presence of surface contaminants should be reported on the ATIS. If ATIS is unavailable or significant changes occur, the controller must report this information to aircraft in plain language on the RTF either:
- Individually
- Via an all-stations broadcast, obtaining acknowledgment from each aircraft concerned.
What are the reporting terms for runway surface conditions and their definitions?
- The reporting terms and their definitions are:
- DRY: The runway is free of visible moisture and not contaminated in the area intended for use.
- WET: The runway has visible dampness or water up to 3 mm depth within the intended area of use.
- SLIPPERY WET: A wet runway where the surface friction characteristics of a significant portion are degraded.
- CONTAMINATED: A significant portion of the runway surface area is covered by one or more substances listed in the runway surface condition descriptors (table 2).
Note: The term ‘CONTAMINATED’ is not used in RTF phraseology; specific descriptors are used instead.
What are the descriptors used for reporting runway surface conditions?
The descriptors for reporting runway surface conditions are:
- COMPACTED SNOW: Snow compacted into a solid mass allowing airplane tires to run without significant compaction or rutting.
- DRY SNOW: Snow that cannot form a snowball.
- FROST: Ice crystals formed from airborne moisture on a surface below freezing (0°C), more granular than ice.
- ICE: Frozen water or compacted snow transitioning into ice in cold, dry conditions.
- SLUSH: Water-saturated snow that drains water when handled or splatters when stepped on.
- STANDING WATER: Water deeper than 3 mm.
- WET ICE: Ice with water on top or melting ice, which can be very slippery.
- WET SNOW: Snow that can form a well-compacted snowball but doesn’t release water when squeezed.
Note: Descriptors can be combined (e.g., DRY SNOW ON TOP OF COMPACTED SNOW) and should include depth if applicable.
What other related information should be provided about runway surface conditions?
Additional information should include:
- Details of runway de-icing activities, such as chemical treatment or sanding.
- Presence of snowbanks on the runway, with distance left/right from the runway centerline.
- Any frozen ruts and ridges.
What are the key points for assessing and reporting runway contaminants?
Key points for assessing and reporting runway contaminants are:
- Assessment Area: The most significant portion of the runway, likely to be used for take-off and landing, is assessed. The area may vary for runways with a displaced threshold or unusual configurations.
- Direction of Reporting: Reports for each third of the runway should be given in the direction of take-off or landing.
Information Included in Reports:
- Aerodrome location
- Date and time of assessment
- Runway-in-use designator
- Runway Condition Code (RWYCC) for each third of the runway
- Type of contaminant
- Depth of contaminant
- Percentage coverage of contaminant
- Available width and/or length
- Other related information
Associated phraseology for these reports is detailed in CAP 413.
What should be done with pilot reports of braking action?
Pilot reports of braking action should be passed to the Aerodrome Operator as soon as practicable. These reports enable the Aerodrome Operator to consider reassessing the Runway Condition Code (RWYCC) in accordance with the Runway Condition Assessment Matrix (RCAM).
What are the Runway Condition Codes (RWYCC) and their associated descriptions in the RCAM?
The Runway Condition Codes (RWYCC) and descriptions are:
- 6: DRY
- 5: FROST, WET (up to 3 mm depth), SLUSH, DRY SNOW, WET SNOW.
- Braking deceleration and direction control are normal. Braking action: GOOD.
- 4: COMPACTED SNOW (-15°C and colder).
- Braking deceleration or directional control is between Good and Medium. Braking action: GOOD to MEDIUM.
- 3: SLIPPERY WET, DRY/WET SNOW on COMPACTED SNOW, DRY/WET SNOW (more than 3 mm), COMPACTED SNOW (warmer than -15°C).
- Braking deceleration is noticeably reduced, or directional control is noticeably reduced. Braking action: MEDIUM.
- 2: More than 3 mm depth of water or slush, STANDING WATER, SLUSH.
- Braking deceleration or directional control is between Medium and Poor. Braking action: MEDIUM to POOR.
- 1: ICE.
- Braking deceleration is significantly reduced, or directional control is significantly reduced. Braking action: POOR.
- 0: WET ICE, WATER on COMPACTED SNOW, DRY/WET SNOW on ICE.
- Braking deceleration is minimal to non-existent, or directional control is uncertain. Braking action: LESS THAN POOR.
Note: Runway surface temperature should be used where available. The aerodrome operator may assign a higher RWYCC (up to RWYCC 3) following specific procedures.
How should unofficial observations of runway surface conditions be handled and reported?
Unofficial observations should be handled and reported as follows:
- Pilots’ Reports: If pilots or visual room observations suggest the runway surface condition is worse than the official report, this information must be passed along. However, if the unofficial report suggests better conditions, it should not be passed.
- Reporting Term: Unofficial observations should be prefixed with “Unofficial observation” and describe the entire runway condition with a single term.
- Action: Pilot reports should be passed to the Aerodrome Operator as soon as practicable.
What should be done if abnormal conditions on the runway are suspected to be due to an obstruction in the drainage system?
The Aerodrome Operator should be notified immediately if it is suspected that abnormal conditions are due to an obstruction of the runway drainage system.
What is the policy regarding the use of Continuous Friction Measuring Equipment (CFME) on runways contaminated with wet snow, slush, or water?
The CAA policy states that CFME should not be used on runways contaminated with wet snow, slush, or water, and controllers must not pass runway coefficient of friction measurements to pilots in such conditions. This is because readings from CFME (like ‘Griptester’ and ‘Mu-meter’) are considered unreliable and may indicate better conditions than actually exist. UK runways contaminated with compacted snow and ice are not normally available for use, following a ‘back to blacktop’ policy.
Further details are found in UK Reg (EU) No. 139/2014 ADR.OPS.B.035, CAP 168 Licensing of Aerodromes Appendix 3D, and UK AIP (AD) section.
