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In an AIP, navaids that are situated at a runway direction are published in section AD 2.19 / AD 3.18 Radio navigation and landing aids.
Significant Point
in In AIXM 5, the instance of a Navaid class is related to the SignificantPoint class (see also topic SignificantPoint [SPN]). The Significant point may be used as start or end point of a route or terminal procedure, or the centre point of a TAA/MSA, to describe the horizontal border of an airspace, etc.
Hence, navaids that are used as significant point have to be encoded using the Navaid class, whereas other navaids may be just encoded as NavigationEquipment (e.g. a marker beacon that is part of an ILS installation or a DME that is part of a VOR/DME).
Coding Rules for Basic Data for Navaid
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