[Lot 4] AIXM-505 Revised Runway Approach Guidance classification

Description

The precisionApproachGuidance attribute of the RunwayDirection class is renamed approachGuidance and it gets a new list of values CodeRunwayApproachGuidanceType.

Rationale for change

In the current model, the RunwayDiretion has a precisionApproachGuidance attribute that indicates if the runway is supported by navaids and if these navaids are suitable for a certain level of precision approaches. The same list of values CodeApproachGuidanceType list of values is used in the FinalLeg. The Change Proposal AIXM-473 will remove that attribute and the list of values CodeApproachGuidanceType list of values will remain associated only with the RunwayDirection.precisionApproachGuidance. The following UML class diagram presents the result of this change:

The following issues have been identified:

• the model is not aligned with the ICAO Annex 14, which classifies the runways considering all visual and non-visual aids, not only the navaids. In addition, it is no longer appropriate to link a precision approach category to ILS or MLS, as precision approaches are now possible also using Global Navigation Satellite Systems (GNSS);
• the value ILS_IIID does not correspond to anything in the ICAO provisions or in the real world and should be removed;
• an explicit value for non-instrument runway is missing from the list.

In order to reflect the true nature of this runway classification, it is proposed that the word “precision” is taken out from the RunwayDirection attribute and that the list of values is aligned with the ICAO Annex 14 provisions.

Impact assessment

When providing AIXM 5.1(.1) data to AIXM 5.2 systems, the forward mapping rules described further in this document may be applied.

When receiving data from AIXM 5.2 implementations, the backward mapping rules described further in this document may be applied in order to recuperate the data. These conversion rules are based on the current AIXM 5.1(.1) workarounds.

Change Proposal details

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Mapping AIXM 5.1.1 to AIXM 5.2 (forward)

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Mapping AIXM 5.2 to AIXM 5.1.1 (backward)

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Mapping example

(Note: for mapping test data see: https://github.com/aixm/mapping_52_511/tree/master/AIXM-xxx) 

AIXM 5.2	AIXM 5.1(.1)