[UK] Air Traffic Control Data - RNAV SUBSTITUTION

INTRODUCTION

Modernising the UK airspace design, UK ground-based radio navigation infrastructure is partially decommissioned to create an ‘exclusive use of PBN’ by the use of RNAV Substitution. Relevant information is contained in CAP 1926.

（使）現代化 Modernizing is predominantly used in American (US) English ( en-US ) while modernising is predominantly used in British English (used in UK/AU/NZ) 退役專用的/獨佔的

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RNAV Substitution depends on a coding of the conventional procedure into the navigation data base whereas it has not been originally designed with that intention. As a consequence, there are limitations associated with RNAV Substitution and required operating procedures, in order to maintain the same level of safety.

In the UK, RNAV Substitution may be envisaged in a number of operational scenarios:

設想/展望可能發生的事態

Short-term ground-based radio navigation aid outage (notionally one NOTAM cycle) due to maintenance or failure.

DVOR/DME/NDB rationalisation where there will be a long-term (greater than 90 days) outage due to planned decommissioning of a ground-based navigation aid which supports conventional procedures or segments, pending the introduction of new PBN procedure.

New aircraft delivery without ADF installed or Minimum Equipment List (MEL) dispatch relief. 救援?

Instrument Approach Procedures with a Missed Approach segment defined by reference to ground-based navigation aids.

Requirements

Operator/pilot may fly conventional procedures using the FMS/Area navigation system for primary navigation without monitoring the raw data of the radio navigation aids designated by the conventional procedure, provided that the operational criteria for RNAV Substitution are complied with. The use of an FMS/Area navigation system without monitoring the primary navigation aid is subject to the criteria outlined per CAP 1926. Where the provisions cannot be complied with, monitoring the conventional radio navigation aids will still be required. A specific operational approval or authorization is not intended to do so.

Commercial Air Transport (CAT) operators are expected to have made the appropriate amendments to the Operations Manual detailing procedures and flight crew training pertinent to the use of RNAV Substitution. Operators should manage associated risks in implementing RNAV Substitution operations.

實施/貫徹

For other commercial and non-commercial operators/pilots, this guidance should be read in conjunction with other applicable regulatory material.

Scope and Limitations

RNAV Substitution may be used in all phases of flight in UK airspace, except to provide lateral guidance in the final approach segment of an Instrument Approach Procedure (IAP). Applications of RNAV Substitution include:

determination of aircraft position relative to or distance from:

a Very High Frequency Omnidirectional Radio range (VOR);
a Marker;
a DME fix; or
a named fix defined by a VOR radial or Non-Directional Beacon (NDB) bearing and DME distance.

– navigation to or from a VOR, or NDB, except as lateral guidance in the final approach segment of an Instrument Approach Procedure (IAP);

– holding over a VOR, NDB, or DME fix;

– flying an arc based upon DME;

– where a route or procedure is defined by reference to conventional radio navigation aids and coded as an overlay which may be selected from the navigation data base and executed: （尤指有計劃地）實施

flying a departure or arrival route (SID or STAR); or
flying the Initial, Intermediate or Missed Approach segments of an Instrument Approach Procedure (IAP).

NOTE: Operators/pilots may apply RNAV Substitution as an alternative means of compliance where charts indicate that a published route or instrument approach procedure segment is not available without a particular conventional radio navigation aid e.g., NDB(L).

RNAV Substitution for ADF, VOR or DME may be used where the aircraft equipment is not installed or is inoperative and/or the ground-based radio navigation aid is either inoperative or unreliable. For the Initial, Intermediate and Missed Approach segments of an Instrument Approach Procedure (IAP), the entire procedure must be coded as an overlay procedure, from which it may be selected from the navigation data base and executed.

For VOR and DME, RNAV Substitution should not encourage operators/pilots to remove VOR or DME, which remain as standard equipment.

RNAV Substitution shall not be applied to any route or procedure where RNAV Substitution has been indicated as “not authorized” in the UK Aeronautical Information Publication (AIP) entry or by NOTAM.

Additional information regarding the validation of procedures and the use of radio navigation aids is provided in the Quality Assurance Manual for Flight Procedure Design (Doc 9906), Volume 5 - Validation of Instrument Flight Procedures; and the Performance-based Navigation (PBN) Manual (Doc 9613).

Operating Procedures

The pilot-in-command is responsible for:

applying pre-flight procedures associated with GNSS use e.g., Receiver Autonomous Integrity Monitoring (RAIM) check, if applicable;

checking that the navigation database is current;

ensuring that any procedures and waypoints used are retrieved from the navigation database;

verifying waypoint sequence, reasonableness of track angles, and distances of any coded overlay procedure used and in particular, where the use of RNAV Substitution is used to replace offset DME with a zero-range indication, associated with an ILS;

ensuring that FMS/Area navigation system and the GNSS systems are operational; and

complying with any limitation on RNAV Substitution in the AFM and manufacturer’s documentation.

The pilot shall be aware of the limitations of RNAV Substitution and familiar with the operator’s policy (if applicable), and operating procedures.