Definition
A NAVAID is any ground-based or space-based facility that provides signals pilots use to determine position, track a course, or fly an instrument approach. Common examples include VOR stations, NDBs, DME, ILS components, and the GPS satellite network. Each NAVAID transmits a signal that aircraft equipment receives and converts into usable navigation information.
Plain English
A NAVAID is a piece of equipment, on the ground or in space, that sends out a signal pilots use to figure out where they are or where they're going.
Context Anchor
Seen in instrument flying, approach procedures, emergency handling, and ATC instructions when navigation guidance is needed.
Derivation
A blend of 'navigation' and 'aid.' Navigation comes from the Latin navigare, meaning 'to sail or steer a ship.' A NAVAID is literally an aid to navigation — something that helps you find your way.
Why Pilots Care
NAVAIDs provide the position references ATC and pilots rely on when radar coverage is limited or during in-flight emergencies.
Intuition Check
Do not think of a NAVAID as a person helping the pilot. In aviation, it usually means equipment, a signal, or a published source of guidance used for navigation.
Example Sentence 1
The pilot checked NOTAMs and saw that the VOR NAVAID at the destination was out of service, so an alternate approach was selected.
Example Sentence 2
With the GPS out, the pilot tuned the nearest NAVAID to maintain course.