ICAO Annex 15 defines Transition altitude as follows:
The altitude at or below which the vertical position of an aircraft is controlled by reference to altitudes.
According to PANS-AIM, the transition altitude is only required for airspaces listed in section "AD 2.17/3.16 ATS airspace" (e.g. CTR).
Note
In AIXM 5.1.1, the transitionAltitude is an attribute of the AirportHeliport feature. There is no association between the Airspace feature and the AirportHeliport feature in AIXM.
Coding Example
Coding example can be found in the Sample AIP Data Set (DONLON).
| No. | Description | XPath Expression |
|---|---|---|
| AHP-EX-01 | Transition Altitude | //aixm:AirportHeliportTimeSlice[@gml:id='AHP_EADD']/aixm:transitionAltitude |