Direction of Cruise Levels

The RouteAvailability class is used to define the direction of the RouteSegment. AIXM provides the possibility to encode if a route segment may be available for just one direction, i.e. 'FORWARD' or 'BACKWARD' or 'BOTH' direction.

The value 'OTHER 'should not be used. Also 'BOTH' should be avoided as for the different direction a different level series will apply. In case a of a bidirectional route two records have to be encoded one for forward and one for backward.

The StandardLevelColumn class is used to define the series of levels. In general the value used will either be 'ODD' or 'EVEN'. 'ODD_HALF' and 'EVEN_HALF' are used for intermediate flight levels, above odd levels (15, 35, 55, 75, ...) or above even levels (5, 25, 45, 65, ...).

The directions forward and backward are related to the implicit direction of a route segment (see topic Basic Data of Route Segment). 'FORWARD' means from the defined start point towards the end point of the related RouteSegment. 'BACKWARD' means from the defined end point towards the start point of the related RouteSegment.

Forward/Backward is equivalent to the little arrow that appears in the ENR 3.x tables in the AIP, to indicate the direction of flight which is concerned by odd/even.

In addtion the AirspaceLayer class may be used to encode limitations on the vertical levels. In case the AirspaceLayer class is used to encode vertical limits they have to correspond with the values specified in the StandardLevelColumn.

Coding Rules for Direction of Cruise Levels

Coding Examples