BRNAV OPERATIONS IN EUROPEAN AIRSPACE AREA NAVIGATION RNAV

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. – RNP 1 – RNP 4 – RNP 12. 6 – RNP 20 + 1. 0 NM + 4. 0 NM + 12. 6 NM + 20. 0 NM (+ 1. 85 km) (+ 7. 4 km) (+ 23. 3 km) (+ 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 groundbased 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 23 rd of April, 1998.

EUROCONTROL STANDARD • The carriage of B-RNAV equipment approved for RNP 5 operations is mandatory on the entire ATS route network in the ECAC area including designated feeder routes (SIDs & STARs) in / out of notified TMAs. • RNP 5 (B-RNAV) - effective 23 rd April, 1998. • RNP 1 (Precision R-NAV) - to be implemented in 2005.

B-RNAV APPROVAL • Airworthiness approval. – Boeing 747 -200/300/400 – Airbus 310 -300, 330, 340 • Operational approval.

AIRBORNE NAVIGATION EQUIPMENT • They encompass. . – Systems which use external navigation aids such as VOR / DME, DME / DME, GNSS, 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 BRNAV 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.