B-RNAV OPERATIONS IN EUROPEAN AIRSPACE

AREA NAVIGATION (RNAV)

• A method of navigation which permits aircraft operation on any desired flight path.

NAVIGATION PERFORMANCE ACCURACY

• Total navigation accuracy based on the combination of the navigation sensor error, airborne receiver error, display error and flight technical error. Also called system use accuracy.

REQUIRED NAVIGATION PERFORMANCE (RNP)

• A statement of the navigation performance accuracy necessary for operation within a defined airspace.

RNP CONCEPT

• RNP concept applies to navigation performance within an airspace and therefore affects both the airspace and the aircraft.

• RNP is intended to characterize an airspace through a statement of the achieved navigation performance accuracy to be achieved within the airspace. Contd..

..RNP CONCEPT

• The development of the RNP concept recognizes that the current aircraft navigation systems are capable of achieving a predictable level of navigation performance accuracy and that a more efficient use of available airspace can be realised on the basis of this navigation capability.

DEFINING RNP AIRSPACE

• RNP may be specified for a route, a number of routes, an area, volume of airspace or any airspace of defined dimensions which an airspace planner or authority chooses.

Some potential applications of RNP include..

• A defined airspace, such as MNPS airspace; • A fixed ATS route, such as between Sydney, Australia and Auckland, New Zealand; • Random track operations, such as between Hawaii and Japan; and • A volume of airspace, such as a block altitude on a specified route.

RNP ROUTES

• Fixed RNP Route - Permanent, published ATS routes.

• Contingency RNP Routes - published ATS routes during limited time periods (Hours, Days, Seasons). They may also be established to meet unusual, temporary requirements arising at short notice.

CONTAINMENT VALUE

• The containment value is the distance from the intended position within which flights would be found for at least 95% of the total flying time.

RNP TYPE

• The RNP type is based on a navigation performance accuracy value which is expected to be achieved at least 95% of the time by the population of aircraft operating within the airspace.

RNP TYPES

• Accuracy - 95% position accuracy in the designated airspace.

– RNP1 + 1.0 NM (+ 1.85 km) – RNP 4 + 4.0 NM (+ 7.4 km) – RNP 12.6

+ 12.6 NM (+ 23.3 km) – RNP 20 + 20.0 NM (+ 37 km)

RNP COORDINATE SYSTEM

• ICAO has chosen World Geodetic System (WGS)-84 as the common world geodetic datum as there is a need to : – convert coordinates of airport key positions and ground-based navigation aids to a common geodetic reference datum; – ensure that all such locations are surveyed to a common standard which provides optimum accuracy, such as that obtained by GNSS surveying techniques; and – ensure that all FMS software is referenced to a common geodetic datum.

BASIC RNAV

+ 5 NM ( + 9.26 km )

(95% CONTAINMENT VALUE) B-RNAV Operations commenced in European airspace on the 23rd of April, 1998.

EUROCONTROL STANDARD

• The carriage of B-RNAV equipment approved for RNP5 operations is mandatory on the entire ATS route network in the ECAC area including designated feeder routes (SIDs & STARs) in / out of notified TMAs.

• RNP5 (B-RNAV) - effective 23rd April, 1998.

• RNP1 (Precision R-NAV) - to be implemented in 2005.

B-RNAV APPROVAL

• Airworthiness approval.

– Boeing 747-200/300/400 – Airbus 310-300 • Operational approval.

AIRBORNE NAVIGATION EQUIPMENT

• They encompass..

– Systems which use external navigation aids such as VOR / DME, DME / DME, GNSS, OMEGA / very low frequency (VLF), LORAN-C; and – systems which are self-contained, e.g. INS, or inertial reference systems.

Required Functions of B-RNAV Navigation Equipment

• Continuous indication of aircraft position relative to track displayed on a navigation display to both the pilot flying and the pilot not flying.

• Display of distance and bearing to the next active (TO) waypoint.

• Display of ground speed or time to the next active (TO) waypoint.

• Storage of waypoints; minimum of 4.

• Appropriate failure annunciation of the RNAV system, including sensors.

Recommended Functions of B RNAV Navigation Equipment

• Autopilot and / or Flight Director coupling.

• Present position in terms of latitude and longitude.

• “Direct To” function.

• Indication of navigation accuracy (e.g. quality factor ).

• Automatic channel selection of radio navigation aids.

• Navigation data base.

• Automatic leg sequencing and associated turn anticipation.

FLIGHT CREW CONTINGENCY PROCEDURES • In case of contingencies, (equipment failures, weather conditions) crew should notify ATC about the ability to maintain navigation accuracy, state its intentions, co-ordinate a plan of action and obtain a revised ATC clearance. • If unable to notify ATC, crew should follow established contingency procedures and obtain ATC clearance as soon as possible.