Definition
Ground-based or satellite-based radio transmitters that send signals pilots use to determine their position, track a course, or navigate to a specific point. Common examples include VOR (VHF Omnidirectional Range), NDB (Non-Directional Beacon), DME (Distance Measuring Equipment), ILS (Instrument Landing System), and GPS (Global Positioning System).
Plain English
Radio signals from stations on the ground or satellites in space that help a pilot know where they are and where they're going. The aircraft picks up the signals and shows the pilot useful information like direction, distance, or a path to follow.
Context Anchor
You see this term during preflight planning when checking what navigation help is available along the route and near the destination.
Derivation
Radio comes from the Latin radius, meaning 'ray' or 'beam,' and refers to invisible signals that travel through the air. A navigation aid is something that helps you find your way. Together, the term describes signals that guide an aircraft.
Why Pilots Care
They let pilots navigate accurately in low visibility and are required for most instrument flight operations.
Intuition Check
Do not read this as ordinary radio talking. Here, “radio” means signals used for navigation, not voice communication with another person.
Example Sentence 1
Before departure, the pilot identified the radio navigation aids along the route and noted their frequencies on the flight log.
Example Sentence 2
The airplane stayed on course using radio navigation aids when clouds hid the ground.