Route (overview)

The figure below shows the main AIXM 5.1(.1) classes used for the route concept.

A Route consists of one or more RouteSegment. A route is identified by its designator, which consists of three main elements: a designatorPrefix (e.g. 'U' for Upper), a designatorSecondLetter (e.g. 'L'), a designatorNumber (e.g '601'). In addition, the multipleIdentifier corresponds to an additional letter that appears sometimes in a route designator (e.g 'A' for an alternate route). The route designator suffix specified in the ICAO Annex 11, which indicates the level of traffic separation service (e.g. 'F' for an advisory route) is modelled with the RouteSegment.designatorSuffix, as it could be applicable to just a few segments of a longer route. The locationDesignator attribute goes beyond the ICAO requirements and it allows indicating the geographical location of a route, using for example country codes or region codes.

Each RouteSegment starts at and ends at an EnRouteSegmentPoint, whereas the start point of a following route segment is the end point of the previous one. The en-route segment points are a choice of SignificantPoint. For route segments that may be a Navaid, a DesignatedPoint or in rare cases also the ARP of an AirportHeliport. See also SignificantPoint (Overview).

The upperLimit and the lowerLimit attributes correspond to the vertical extent of the RouteSegment, with additional vertical constraints being modelled with attributes such as minimumObstacleClearanceAltitude, minimumEnrouteAltitude, etc. The RouteSegment is further defined by a length,a trueTrack and/or a magneticTrack. Also a requiredNavigationPerformance value may be provided.

Each route segment may have a RouteSegmentAvailability. The availability of a route segment includes an association with the predefined series of cruise levels (odd or even) defined by the StandardLevelColumn.

A controlling Unit may provide InformationService or AirTrafficControlService on a RoutePortion, using one or more RadioCommunicationChannel.

For VOR-defined routes, a ChangeOverPoint may be specified for a certain RoutePortion.