Plain English Meaning

Older-style radio beacons on the ground that aircraft tune in to find their position and follow courses. They are the traditional ground-based navigation system, as opposed to GPS which uses satellites.

Full Definition

Ground-based radio navigation aids that transmit signals from a fixed station on the earth's surface, which aircraft receivers use to determine bearing, distance, or course. The principal conventional NAVAIDs in U.S. airspace are the VOR (very high frequency omnidirectional range), DME (distance measuring equipment), (non-directional ), , and the (). They are called 'conventional' to distinguish them from such as GPS.