Plain English Meaning
Whether a ground-based navigation aid is working normally, partially working, or not usable right now. Pilots check this before relying on it for navigation or an approach.
Full Definition
The current operational condition of a navigational aid (such as a VOR, ILS, or NDB), indicating whether it is in service, out of service, operating with restrictions, or undergoing maintenance or flight check. NAVAID status is published through NOTAMs, ATIS broadcasts, and controller advisories, and directly affects whether a may legally and safely use that facility for navigation or .