Definition
In NOTAM usage, NAV is the keyword identifier indicating that a NOTAM concerns navigation aids — ground-based equipment such as VORs, NDBs, DMEs, ILS components, or other electronic navigation facilities that may be out of service, on reduced capability, or otherwise affected.
Plain English
NAV is a tag used in NOTAMs to flag that the notice is about a navigation aid — for example, a VOR or ILS that is unavailable or working at reduced capability.
Context Anchor
Seen in NOTAMs as a category label for notices about navigation equipment or navigation services.
Derivation
Short for 'navigation,' from Latin navigatio, meaning the act of sailing or steering a vessel. In aviation, navigation refers to determining and following a route, so NAV-tagged NOTAMs are about anything affecting the equipment that helps pilots do that.
Why Pilots Care
A NAV NOTAM may mean a navigation aid you planned to use is out of service. If you were counting on a VOR for an approach or enroute fix, you need to know before takeoff so you can plan an alternate route, approach, or method.
Intuition Check
Do not read NAV as a general label for the whole flight plan. In a NOTAM, it specifically points to navigation aids or navigation services affected by the notice.
Example Sentence 1
During preflight, the pilot reviewed the NAV NOTAMs and saw that the destination VOR was out of service.
Example Sentence 2
Pilots check NAV status before departing into instrument conditions.