ATS routes and navigation specifications

Read a route designator

The route identifier and its required capability answer different questions.

Composition

A basic ATS route designator uses a letter and a number from 1 to 999. The letter series distinguishes conventional and area-navigation routes and whether the route forms part of the regional network. A, B, G and R identify conventional regional routes; L, M, N and P identify regional RNAV routes. H, J, V and W are conventional non-regional; Q, T, Y and Z are non-regional RNAV.

A prefix such as U can indicate the upper airspace portion; K and S have their prescribed helicopter/supersonic route meanings where used. Other suffixes may describe an advisory or information-service condition as specified. Pronounce the complete applicable designator; the published AIP determines the route’s current structure and availability.

Navigation performance is not hidden in the route name

RNP means required navigation performance and is a PBN specification with onboard performance monitoring and alerting. The specification depends on the airspace concept and requirements for accuracy, integrity, continuity, availability and functionality. RNP 1 is not simply “GPS installed”.

The prescribed navigation specification is published with the route/airspace requirement; it is not an integral element encoded by the basic ATS route designator. Two routes with similar names may need different capabilities or approvals. Confirm database, sensors, monitoring and contingency requirements for the actual flight.

Can you apply the rules?

Four original questions. Choose from the facts, then review the explanation.