This topic contains only those PANS-AIM requirements relevant for a NDB. For general PANS-AIM requirements valid for all kind of Radio navigation aids see topic Navaid [NAV] and subordinated pages.
A Non-directional radio beacon (NDB) is a low or medium frequency radio beacon which transmits signals whereby the pilot of an aircraft properly equipped can determine bearings and 'home in' on the station.
A Locator is an LF/MF NDB used as an aid to final approach.
For a NDB, PANS-AIM requires some specific properties as part of the minimum AIP data set. These are
...magnetic variation, frequency...
The diagram below shows the AIXM classes, including the relevant data types, needed to encode that information The main class is the NDB which is a specialisation of the NavaidEquipment.
NDB Frequency
In AIXM 5 the frequency of the NDB emission is coded by using the NDB.frequency attribute.
The corresponding data type contains a uom attribute. For a NDB only the value equal-to 'KHZ' shall be used.
According ICAO Annex 10, Volume 1 the radio frequencies assigned to NDBs shall be selected from those available in that portion of the spectrum between 190 kHz and 1 750 kHz.
Magnetic Variation
For NDB PANS-AIM Appendx 1 requires the magnetic variation to be provided. For details about the encoding including rules see the topic Magnetic Variation.
NDB Type
This information is not explicitly required by PANS-AIM. However, this information may be relevant for ARINC 424 coding.
In AIXM 5 the Navaid.type attribute may carry the value; 'ENR' for Enroute NDB, 'L' for Locator - low powered NDB used as an aid for final approach (also known as a compass locator) and 'MAR' for Marine beacon.
ARINC 424 contains 2 dedicated record types for NDB. One for NDB NAVAID (DB) containing all LF and MF NDBs and selected Marine Beacons defined in the enroute structure and one for the Terminal NDB (PN). Both record types contain the data field NAVAID Class (CLASS), that, inter alia, is used to distinguish between NDB, Locator and Marine Beacon (additional classification elements are part of this data field which do not fully coincide with AIXM 5 concept, e.g. codes for high powerd NDB , low powered NDB, etc.).
Navaid Component
An NDB may be co-located with a MarkerBeacon or a DME.
For details about the coding and rules see topic Landing Systems & Navaid Collocation.
Coding Rules for NDB
TBD
Coding Examples
Th efigure below shows an example of different types of NDBs published in ENR 4.1. of an AIP.
More examples TBD in the scope of the DONLON AIXM AIP data set.