• The PBN specifications are described in the ICAO PBN Manual, Doc 9613, where safety assessment considerations and implementation guidance for the identified navigation specifications are considered together with the background and purpose for each specification. 

    The implementation considerations for the ANSP, the approval processes, the detailed aircraft requirements and operating procedures are identified along with specific pilot knowledge and training where applicable.  The navigation specification also details any requirements for control of navigation database and oversight of operators.

    The transition to PBN

    The ambition for deployment of PBN in UK airspace is the utilisation of the most relevant PBN specification for the intended operation.  Although RNAV 1 is the basis of future terminal airspace developments, this does not preclude the use of RNP 1 or Advanced RNP performance and functionality where appropriate.  As airspace redesign developments are introduced, choice of navigation specification will need to have regard to the aircraft fleet capability.

    PBN terminology

  • RNAV is a method of navigation which permits the operation of an aircraft on any desired flight path; it allows its position to be continuously determined wherever it is rather than only along tracks between individual ground navigation aids.

    RNP specifications have an additional requirement for on-board performance monitoring and alerting. This means that if the RNP system does not perform the way it should then an alert should be provided to the flight crew.

    In practical terms what this means is that ATC can have greater confidence in the track keeping performance of the aircraft and this greater confidence translates into being able to place routes closer together.

    Repeatable and predictable turn performance:

    • Maintaining the same spacing between routes on straight and turning segments without a need to increase route spacing on the turn;
      and
    • Means of enabling curved approaches, particularly through terrain rich areas (applicable to RF only).

    Both functionalities are associated only with RNP specifications. RF is a path terminator used for SIDs, STARs and Approach. FRT is a leg transition used when the FMS is in the en-route mode.

    A PinS approach is an instrument RNP APCH procedure flown to a point-in-space from which a Missed approach or visual approach to land can be instigated. It may be published with LNAV and/or LPV minima.

    Comprises various elements outlined in this RNP approach overview.

  • Applications

    The International Civil Aviation Organization’s (ICAO) PBN Manual (Doc 9613) identifies three RNAV navigation specifications with their intended applications: 

    • RNAV 10 for use in en-route oceanic remote airspace;
    • RNAV 5 is for continental en-route applications;
    • RNAV 1 is principally a terminal airspace application, including departures and arrivals and including approach transitions.  RNAV 1 may also be applied in continental en-route applications such as ATS or user defined routes.

    Doc 9613 identifies seven RNP navigation specifications with their intended applications:

    • RNP 4 is for oceanic and remote continental navigation applications; 
    • RNP 2 is for en-route oceanic remote and en-route continental navigation applications; 
    • RNP 1 is for arrival and initial, intermediate and missed approach as well as departure navigation applications;
    • Advanced RNP is for navigation in all phases of flight;
    • RNP 0.3 is for the en-route continental, the arrival, the departure and the approach (excluding final approach) phases of flight and is specific to helicopter operations;
    • RNP APCH is for navigation applications during the approach phase of flight;
    • RNP AR (Authorisation Required) APCH requires a Specific Approval and is used in approach applications where reduced obstacle assessment, lower than standard RNP lateral accuracy and use of RF inside the final approach segment, might be used.
  • Related Information

    The ICAO PBN Manual (ICAO Doc 9613 Edition 4) consists of two volumes:

    Volume I

    • Part A describes the PBN Concept, its role within the airspace concept and how the PBN Concept is used in practice;
    • Part B provides Implementation Guidance for ANSPs in the form of the processes, phases and steps;
      Attachments describe RNAV and RNP systems, data processes and an outline of the operational approval process. 

    Volume II

    • Part A provides a general introduction to the navigation specifications, including specific guidance on on-board performance monitoring and alerting, safety assessments and navigation service monitoring;

    • Part B contains the RNAV navigation specifications, to be used by States as a basis for certification and operational approval;

    • Part C contains the RNP navigation specifications to be used by States as a basis for certification and operational approval;

    • Attachments describe Barometric VNAV and provide sample airspace concepts based on navigation specifications.

    ICAO Manual on the use of Performance-based Navigation (PBN) in Airspace Design (ICAO Doc 9992 Edition 1)
    Performance-based Navigation (PBN) Operational Approval Manual (ICAO Doc 9997 Edition 2).