Plain English Meaning

Groups of official airway routes that stay inside one part of the world, like Europe or North America, rather than crossing between regions. They get their own set of identifying letters when named on charts.

Full Definition

Sets of published Air Traffic Service (ATS) routes that are organized and designated for use within a specific geographic region of the world, as opposed to routes that cross between regions. Within ICAO's route designator system, regional networks are identified by a basic letter (A, B, G, R) for conventional routes or (L, M, N, P) for area navigation (RNAV) routes.

Context Anchor

Seen in instrument procedure and airway-designator discussions, especially when explaining why certain route names begin with certain letters.