The surface condition report event scenario describes information about contaminations on one or multiple runways, taxiways and/or aprons at one airport.
- The objective of this scenario is to support the encoding of contamination information about individual runways, taxiways or aprons, as foreseen to be contained in SNOWTAM messages as of 04 November 2021 (ICAO) or 12 August 2021 (EU);
- Several runways, taxiways and aprons can be included in the surface condition report;
- The content of the report is considered as described in ICAO Doc 10066 - Aeronautical Information Management, First Edition, Amendment No. 2, 2018, Appendix 4 - SNOWTAM Format and CIR (EU) 2017/373 as amended by CIR (EU) 2020/469 and CIR (EU) 2020/1177 - Appendix 3 SNOWTAM Format.
- This scenario does not support the encoding of the information about airport, runway closure due to contamination. That information should be encoded using the dedicated AD.CLS or RWY.CLS scenarios.
The following diagram identifies the information items that are usually provided by a data originator for this kind of event.
|ICAO SNOWTAM item mapping
Aeroplane performance calculation section
|The published designator of the airport/heliport concerned. This information, in combination with eventually the name is used to identify the airport/heliport.
Aerodrome location indicator
|The published name of the airport/heliport. This information, in combination with the designator is used to identify the airport/heliport.
|The date and time of the assessment.
Date-time of assessment
The designator of the runway for which the assessment is provided.
Note: In a SNOWTAM message only the runway direction designator with the lowest number is inserted for each runway. The HMI should support the operator in assuring the proper selection of the runway by displaying the full designator for selection.
Lower runway designator number
Indicates the part of the runway for which the assessment is provided. This supports indicating contamination information on each third of the runway length.
Note: the data input template groups the information per runway third. In practice, data originator might prefer to group the information by SNOWTAM item and list all thirds with a "/" separator. The application HMI shall support the operator selection with visual or textual aids so that the order of the thirds are correctly provided i.e. that the first third corresponds with the first third from the RWY side with the lower designator number.
RWYCC on runway section
|Runway condition code for each runway third.
Runway.areaContaminant.RunwaySectionContamination.frictionEstimation with values 'OTHER:RWYCC_code'
Runway Condition Code (RWYCC) on each runway third
|The coverage of the contaminant in per cent for each runway third.
Per cent coverage contaminant for each runway third
loose contaminant depth
|Indicates the depth (mm) of loose contaminant for each runway third
Runway.areaContaminant.RunwaySectionContamination.depth with uom='MM'
Depth (mm) of loose contaminant for each runway third
contaminant layer order
|Indicates the order of the layer (starting from the uppermost, towards the movement area surface), in case overlapping contaminants are present.
Indicated the contaminant observed on each runway third.
Condition description over total runway length.
|Width of runway cleared of contamination, if less than the total width.
Runway.overallContaminant.RunwayContamination.clearedWidth with uom="M"
Width of runway to which the runway condition codes apply, if less than published width
Situational awareness section
reduced runway length
|Length of runway cleared of contamination, if less than the total length of the runway.
Runway.overallContaminant.RunwayContamination.clearedLength with uom='M'
Reduced runway length, if less than published length
Indication of the presence of drifting snow, loose sand and/or chemical treatment on the runway.
Note: The HMI should support the operator by providing only the three options available for input.
(for larger airports, where drifting snow occurs on multiple runways, but not all) Runway.overallContaminant.RunwayContamination.layer.SurfaceContaminationLayer.type
|Item J) Drifting snow on the runway
Item K) Loose sand on the runway
Item L) Chemical treatment on the runway
|Indication of the side of the runway relative to its centreline where snowbanks are present.
Snowbanks on the runway (from centreline)
|Indication of the distance from the runway centreline where snowbanks are present.
Runway.overallContaminant.RunwayContamination.criticalRidge.Ridge.distance with uom="M" and
Ridge.annotation with propertyName='distance', purpose='DESCRIPTION' and note='distance measured from runway centerline'
adjacent snowbank presence
|Indication of the presence of snowbanks adjacent to the runway
|Runway.overallContaminant.RunwayContamination.annotation.Note with purpose='REMARK' , propertyName='criticalRidge' and note='Snowbanks present adjacent to the runway'
Snowbanks adjacent to the runway
|The designator of the taxiway for which the assessment is provided.
Snowbanks on a taxiway
taxiway snowbank presence
|Indication of the presence of snowbanks on a taxiway
Taxiway.contaminant/TaxiwayContamination.annotation.Note with purpose='REMARK' , propertyName='criticalRidge' and note='Snowbanks present on the taxiway'
taxiway surface condition
|Indication of the taxiway surface condition
|all taxiway poor
|Indication that all TWY at the airport are in poor condition
AirportHeliport.contaminant.AirportHeliportContamination.annotation.Note with purpose='REMARK' and note='All TWYs poor'
|The designator of the apron for which the assessment is provided.
apron surface condition
|Indication of the apron surface condition
|all apron poor
|Indication that all apron at the airport are in poor condition
AirportHeliport.contaminant.AirportHeliportContamination.annotation.Note with purpose='REMARK' and note='All aprons poor'
|Indication of the measured friction coefficient, according to the State approved means.
Measured friction coefficient
friction measuring device
|Indication of the friction measuring device, according to the State approved means.
|A free text note that provides further details concerning the surface condition report.
|AirportHeliport.contaminant.AirportHeliportContamination.annotation.Note with purpose='REMARK'
Plain language remarks
Assumptions for baseline data
It is assumed that following BASELINE TimeSlices covering the entire duration of the event exist and have been coded as specified in the Coding Guidelines for the (ICAO) AIP Data Set:
AirportHeliport BASELINE as specified in the Basic Data for Airport/Heliport,
Runway BASELINE according to the coding rules for Basic Data for Runway;
The coding rules for the situational awareness section provide two options:
(1) using TEMPDELTA TimeSlices for individual Apron and/or Taxiway
(2) using annotations
The first option can be used only when the corresponding BASELINE data is also available:
Taxiway BASELINE which contains as a minimum a designator and an association with the AirportHeliport;
- Apron BASELINE which contains as a minimum a designator and an association with the AirportHeliport;
Both options are detailed in the coding rules and should be supported in the interface. Option 2 (using annotations) should be enable, at the discretion of the data coding operator, even in the situation when Taxiway and Apron BASELINE data is available.
Data encoding rules
The data encoding rules provided in this section shall be followed in order to ensure the harmonisation of the digital encodings provided by different sources. To the maximum possible extent, the compliance with these encoding rules shall be verified with automatic data validation rules.
Data encoding rule
The surface condition report shall be encoded as:
The TimeSlice.validTime of the affected Features TEMPDELTAs, the EventTimeSlice.validTime and EventTimeSlice.featureLifetime shall have TimePeriod.beginPosition equal to the latest of all Runway/RunwayContamination.observationTime coded in relation with the Event
Reason: When reporting on more than one runway and individual dates/times of observation/assessment are indicated by repeated Item B, the latest date/time of observation/assessment is inserted in the abbreviated heading. This is considered the start of the SNOWTAM validity.
The TimeSlice.validTime of the affected Features TEMPDELTAs, the EventTimeSlice.validTime and EventTimeSlice.featureLifetime shall have TimePeriod.endPosition set 8h after the TimePeriod.beginPosition.
Reason: Maximum SNOWTAM validity is 8h.
All three sections (thirds) shall always be present and each of the following values shall only be used once for the Runway/RunwaySectionContamination.section:
Only the following values are allowed for Runway/RunwaySectionContamination.frictionEstimation:
Only the following values shall be used for Runway/RunwaySectionContamination/SurfaceContaminationLayer.type:
Only the following values shall be used for Runway.overallContaminant.RunwayContamination.layer.SurfaceContaminationLayer.type and/or for the AirportHeliport.contaminant.AirportHeliportContamination.layer.SurfaceContaminationLayer.type
In case of multiple Runway/RunwaySectionContamination/SurfaceContaminationLayer.layerOrder, only the following combinations are allowed:
The maximum value of Runway/RunwaySectionContamination/SurfaceContaminationLayer.layerOrder is 2.
|snowbanks adjacent to the runway shall be encoded as Runway.overallContamination.RunwayContamination.annotation.Note with purpose='REMARK' , propertyName='criticalRidge' and note='Snowbanks present adjacent to the runway'
When snowbanks are present on the runway, their presence shall be encoded as Runway.overallContaminant.RunwayContamination.criticalRidge/Ridge.side='LEFT', 'RIGHT' or 'BOTH'
When Runway/RunwayContamination/Ridge.distance is provided, a Ridge.annotation shall be encoded with propertyName='distance', purpose='DESCRIPTION' and note='distance measured from runway centerline'
The AIXM definition of the element is being a distance measured from the edge of the movement area and not from its centreline, therefore an interpretation rule is needed.
|If the assessment is including Taxiway information, TEMPDELTA TimeSlices shall be encoded for each affected Taxiway Feature.
|Snowbanks present on the taxiway shall be encoded as Taxiway/TaxiwayContamination.annotation.Note with purpose='REMARK' , propertyName='criticalRidge' and note='Snowbanks present on the taxiway'.
|If the assessment is including Apron information, TEMPDELTA TimeSlices shall be encoded for each affected Apron Feature.
Only the following values shall be used for Runway.overallContamination.RunwayContamination.frictionDevice:
In case the following items are NOT REPORTED - "NR", xsi:nil='True', nilReason='inapplicable' shall be used for the corresponding AIXM element:
|The AirportHeliport concerned by the surface condition report shall also be coded as concernedAirportHeliport property in the Event.
|The system shall automatically identify the FIR where the AerodromeHeliport is located. This shall be coded as corresponding concernedAirspace property in the Event.