TACAN

In fact, TACAN is not covered by PANS-AIM, as it is considered as military facility, which is not under civil authority (and thus also not covered by ICAO Annex 10, Aeronautical Telecommunications).

However, as a TACAN may be used for navigation purposes for civil aviation, and in some states it is also published in the civil AIP, and is defined in ARINC 424 (VHF Navaid Section (D) and TACAN-Only NAVAID Record (DT)), it is also covered by this coding guidelines.

AIP context

The example below shows TACAN published in an AIP.

For general PANS-AIM requirements valid for all kind of Radio navigation aids see topic Navaid [NAV] and subordinated pages.

A UHF Tactical Air Navigation beacon (TACAN) is a navigation system developed by military and naval forces providing, as far as the navigating pilot is concerned and for suitably equipped aircraft, the same indication as a VOR/DME system (i.e. it provides bearing and distance information).

Hence, for a TACAN the following properties defined in PANS-AIM for the minimum AIP data set for radio navigation aids are correspondingly relevant:

identification, name, aerodrome served, hours of operation, ...channel, position, elevation, ...

...station declination to the nearest degree used for technical line-up of the aid, ...

...If the operating authority of the facility is other than the designated governmental agency, the name of the operating authority shall be indicated in the remarks column. Facility coverage shall be indicated in the remarks column.

The diagram below shows the AIXM classes, including the relevant data types and code lists, needed to encode that information. The main class is the TACAN which is a specialisation of the NavaidEquipment.


TACAN Designator & Name

In general, a TACAN will carry a three letter character identifier. The TACAN.designator attribute is used to code that data.

In case a TACAN is collocated with a VOR, both will have the same designator.

The long name given to the TACAN is coded using the TACAN.name attribute.

Aerodrome Served

See topic Basic Data for Navaid.

Hours of Operation

See topic Hours of Operation for Navaid.

TACAN Channel

The channel of the TACAN system is coded using the TACAN.channel attribute.

The corresponding data type CodeTACANChannelType contains a list of values from '1X' to '126Y'.

AIXM 5.2 Improvements

A change proposal (AIXM-543) for the next AIXM 5.2 version has been approved by the AIXM Change Control Board, where the attribute tuningFrequencyVHF is added.

The coding guidelines provided here are aligned with forward/backward conversion rules contained in the AIXM-543 Change Proposal.

Position

See topic Navaid Position & Elevation.

Elevation

As the TACAN provides distance information, the elevation of its antenna is relevant. It is coded for the TACAN.location using the ElevatedPoint.elevation attribute.

Note

The ElevatedPoint.elevation for the Navaid.location has not to be coded.

As TACAN is not covered by PANS-AIM, no accuracy value is defined for its elevation. However, AIXM provides the possibility to code it using the ElevatedPoint.verticalAccuracy attribute.

Station Declination

The angular difference between the direction of the 'zero bearing', indicated by the station and the direction of the True North at the time the VOR station is calibrated, is coded by the attribute TACAN.declination.

AIXM 5.1(.1) issue_034_TACAN Zero bearing

TACAN does not have an attribute for "zero bearing direction".

Workaround AIXM 5.1(.1): Code a corresponding Note.

Status AIXM 5.2: to be reported to AIXM CCB.

Operating Authority

See topic Operating Authority for Navaid.

Facility Coverage

See topic Facility coverage.

Navaid Collocation

See topic Landing Systems & Navaid Collocation.

Coding Examples

Coding examples can also be found in the Sample AIP Data Set (DONLON).

No.

Description

XPath Expression

NAV-EX-01

TCN-EX-01

VOR/DME

//aixm:NavaidTimeSlice [@gml:id ='NAVTSOSTO'] |

//aixm:TACANTimeSlice [@gml:id ='TACANOSTO']

References