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), NDB (non-directional beacon), TACAN, and the ILS (instrument landing system). They are called 'conventional' to distinguish them from satellite-based navigation such as GPS.
Plain English
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.
Context Anchor
Seen in instrument procedure design and magnetic variation discussions, especially when comparing ground-based navigation with satellite-based navigation.
Derivation
Conventional' comes from the Latin 'convenire,' meaning to come together or agree. In English it has come to mean 'the established or traditional way.' Here it labels the older, established ground-based navigation aids to set them apart from newer satellite-based methods.
Why Pilots Care
Pilots must apply local magnetic variation corrections when using these aids to avoid course errors that satellite procedures largely eliminate.
Intuition Check
Conventional does not mean “best” or “most correct” here. It means traditional ground-based navigation, as opposed to satellite-based navigation.
Example Sentence 1
When flying the airway, the pilot tuned the VOR because the route was based on conventional NAVAIDs rather than GPS waypoints.
Example Sentence 2
Magnetic variation errors are more pronounced when flying conventional NAVAIDs than when using satellite-based routes.