Hours of Operation for Navaid
- Wolfgang Scheucher
- POROSNICU Eduard
- Manfred Beckmann
PANS-AIM requires as part of the minimum AIP data set the hours of operation for radio navigation aids (for both enroute and terminal radio navigation and landing aids).
The diagram below shows the AIXM classes, including the relevant data types and code lists, needed to encode that information.
To encode the hours of operation of a radio navigation and landing aid in AIXM 5, the NavaidOperationalStatus class has to be used.
It is possible to code the availability of a Navaid and also of a NavaidEquipment.
As a general rule, the availability of a NavaidEquipment should only be coded in case a navaid is composed of more than one navaid equipment, whereas at least one of them has a different availability than the others. If for one navaid equipment the availbility is coded, the availability has to be coded for all other navaid equipments of that navaid. For the navaid itself no availability will be coded. E.g. for a VOR/DME, in case the DME and VOR have different working hours, the availability will be encoded for both navaid equipments separately, but not for the navaid.
In case of a navaid composed of one single navaid equipment or a navaid composed of more navaid equipments all having the same working hours, the availability will only be coded for the Navaid. It is not necessary to copy it for the individual navaid equipment(s) (e.g. in case of an ILS, where all components (LOC, GP, Markers) have the same working hours, the availability will only be coded for the navaid).
The NavaidOperationalStatus class carries two attributes:
The signalType attribute may be used to indicate the type of information transmitted by a navaid or other radio emission source (e.g. azimuth or distance) .
The operationalStatus indicates the state of the navaid:
| Value | Description |
|---|---|
| 'OPERATIONAL' | Operating normally. |
| 'UNSERVICEABLE' | Not available. |
| 'ONTEST' | On test, do not use. |
| 'INTERRUPT' | Expect interruptions of the signal. |
| 'PARTIAL' | Operating with limited capabilities. For example, used when just the DME part of a VOR/DME is working. |
| 'CONDITIONAL' | Operative subject to published limitations or conditions. |
| 'FALSE_INDICATION' | Giving false indication, do not use. |
| 'FALSE_POSSIBLE' | False indication possible, use with caution. |
| 'DISPLACED' | Displaced |
| 'IN_CONSTRUCTION' | In Construction |
| 'OTHER' | Other |
For the AIP data set the default value for the hours of operation for a navaid will be 'OPERATIONAL'. Most of the others status are only relevant for an application of the Digital NOTAM concept.
In addition, although not required by PANS-AIM for the minimum AIP data set, the NavaidEquipmentMonitoring class is used to define if the navaid equipment is monitored ('YES') or not ('NO'). Corresponding Timesheet may be used to define the corresponding time constraints.
For details of how to encode the Timesheet see topic Common coding patterns.
Coding Examples
See also topic Navaid [NAV].
Coding examples can also be found in the AIP Data Set - Specimen (DONLON):
| No. | Description | XPath Expression |
|---|---|---|
VOR-EX-01 DME-EX-01 | VOR/DME with hours of operation H24 | //aixm:VORTimeSlice [@gml:id ='VOR_BOR'] | //aixm:DMETimeSlice [@gml:id ='DME_BOR'] |
| NDB-EX-01 | NDB with unknown hours of operation | //aixm:NDBTimeSlice [@gml:id ='NDB DON'] |