Single volume with derived geometry

The horizontal boundary of some airspace may be derived from the horizontal boundary of another airspace. A typical examples are UIR that inherit the horizontal limits of an FIR. The geometry of such airspace can be coded with a single AirspaceVolume, which has its own vertical limits but which does not have its own horizontalProjection. Instead, the AirspaceVolume needs the contributorAirspace and its AirspaceVolumeDependency association class properties. Two possibilities exist:

• only the horizontal projection of the 'parent' Airspace is inherited (AirspaceVolumeDependency.dependency equal-to 'HORZ_PROJECTION'). This is the case for most such airspace. In this case, the AirspaceVolume properties for vertical limits (lowerLimit, upperLimit, etc.) will need also to be coded in order to fully define its geometry);
• the full geometry of the 'parent' Airspace is inherited (AirspaceVolumeDependency.dependency equal-to 'FULL_GEOMETRY'). In this case, which is not very common, the AirspaceVolume properties for vertical limits will be left empty.

In both situations described above the attributes of the association class AirspaceComponentGeometry  (i.e. operation and operationSequence) will not be left empty. 

Coding Example

The figure below shows a simple example of such an airspace.

More coding examples can be found in the AIP Data Set - Specimen (DONLON).