The figure below shows the main AIXM 5 classes used for the airspace concept.
AIXM 5.1.1 defines an airspace as follows:
A defined three dimensional region of space relevant to air traffic.
The main class in this AIXM model is the Airspace class containing the basic data, such as the name and type of the airspace.
...
For the first option, the AirspaceVolume class with a related Surface or Curve (for airspace corridors) will be used for the encoding.
For the second option, the airspace composition will be encoded by using the AirspaceGeometryComponent class or and if applicable (in case of airspace aggregation by reference) also the AirspaceVolumeDependency class.
The class classi of an airspace is encoded using the AirspaceLayer object. An airspace class may be defined for the whole airspace or layers of it.
...