Navigation Specifications and RNAV

Navigation Specifications

The following Navigation Specification approvals have been granted to The Company (refer to AOC Operations Specifications) and are in use within Company's area of operations:

RNAV 5 is an en-route navigation specification which may be used for the initial part of the STAR outside 30 NM and above MSA.

Note(1): The area of application can only be used after the initial climb of a missed approach phase.

RNAV 10

RNAV 10 is an oceanic or remote area specification requiring the aircraft to maintain a track-keeping accuracy of +/- 10 NM without regular updates from ground-based navigation aids. RNAV 10 approval can be based on IRS performance alone (with a time limit of 6.2 h since IRS ground alignment or 5.7 h since last FM radio update).

RNAV 10 airspace supports 50 NM lateral and longitudinal distance-based separation minima, and examples of RNAV 10 airspace exist over the Indian Ocean and in the AFI, SAM and PAC regions.

Contingency procedures for the area in which RNAV 10 operations are to be conducted should be checked and briefed.

RNAV 5

For operations in RNAV 5 airspace, aircraft require a track-keeping accuracy of +/-5 NM for 95% of the flight time. RNAV 5 does not require a navigation database, it only requires the flight management system to store four waypoints, and it does not require waypoint flyby functionality.

In the event of the communications failure, the flight crew should continue with the flight plan in accordance with the published communications failure procedure.

RNAV 2 and RNAV 1

The RNAV 1 and 2 navigation specification is applicable to all ATS routes, including routes in the en-route domain, standard instrument departures (SIDs), and standard arrival routes (STARs). It also applies to instrument approach procedures up to the final approach fix.

RNAV 1 and RNAV 2 routes are envisioned to be conducted in direct controller-pilot communication environments.

During operations in airspace or on routes designated as RNAV 1, the lateral total system error must be within ±1 NM for at least 95% of the total flight time. The along-track error must also be within ±1 NM for at least 95% of the total flight time.

During operations in airspace or on routes designated as RNAV 2, the lateral total system error must be within ±2 NM for at least 95% of the total flight time. The along-track error must also be within ±2 NM for at least 95% of the total flight time.

An RNAV 1 or RNAV 2 SID or STAR must not be flown unless it is retrievable by route name from the on-board navigation database and conforms to the charted route. However, the route may subsequently be modified through the insertion or deletion of specific waypoints in response to ATC clearances. The manual entry or creation of new waypoints by latitude and longitude is not permitted. Additionally, pilots must not change any RNAV SID or STAR database waypoint type from a fly-by to a fly-over or vice versa.

The terminal procedure (RNAV SID, RNAV STAR, RNAV TRANSITION, ...) must be loaded from the FM navigation database and checked for reasonableness, by comparing the waypoints, tracks, distances and altitude constraints (displayed on the F-PLN page), with the procedure chart.

The flight crew must not modify the procedure that is loaded from the navigation database, unless instructed to do so by the ATC (DIR TO, radar vectoring, insertion of waypoints loaded from the navigation database).

The flight crew must notify ATC of any loss of the RNAV capability, together with the proposed course of action. If unable to comply with the requirements of an RNAV route, the flight crew must advise ATS as soon as possible. The loss of RNAV capability includes any failure or event causing the aircraft to no longer satisfy the RNAV requirements of the route.

In the event of a communications failure, continue with the RNAV route in accordance with established lost communications procedures.

RNAV Approach

Not approved.

RNAV Flight Crew Procedures - General

Apart from RNAV navigation procedures described in applicable parts of the OM Part B, the flight crew should:

• Check and review the Aircraft Technical Log and DMI to ensure that there is no defect to navigational equipment that would preclude specific RNAV operations. The MEL identifies those alleviations that are not suitable for specific RNAV operations;
• Confirm that the navigation database is updated. In exceptional circumstances, and for a limited period of time, an aircraft can continue to operate beyond the end of the database cycle, provided it is approved by the national authorities – refer to FCOM, Chapter Operations with an outdated navigation database;
• Crosscheck the cleared flight plan by comparing charts or other applicable resources with the FMS and the aircraft map display. If required, the exclusion of specific navigation aids should be confirmed;
• Note that the correct flight plan suffixes have been filed on the ATC flight plan. The letter ‘R’ should be placed in block 10 of the ICAO flight plan to indicate the pilot has reviewed the planned route of flight and determined the RNAV requirements and the aeroplane and operator approval for RNAV routes. Additional information should be displayed in the remarks section indicating the accuracy capability;
• Request or file RNAV routes only if all the criteria in the relevant State documents are satisfied. If an aeroplane not meeting these criteria receives a clearance from ATC to conduct an RNAV route, the pilot must advise ATC that he is unable to accept the clearance and must request alternate instructions;
• All pilots are expected to maintain route centre-lines, as depicted by on-board lateral deviation indicators and/or flight guidance during all RNAV 1 and RNAV 2 operations, unless authorised to deviate by ATC or under emergency conditions;
• Not modify the flight plan in the RNAV system, if ATC issues a heading assignment, until a clearance is received to rejoin the route or the controller confirms a new route clearance;
• Conduct mandatory cross-checking procedures to identify navigation errors in sufficient time to prevent inadvertent deviation from ATC-cleared routes;
• Verify that the FMS navigation database is current and appropriate for the region of intended operation; the verification must include the navigation aids, waypoints, and relevant coded ATS routes for departure, arrival, and alternate aerodromes;
• Verify proper entry of their ATC assigned route upon initial clearance and any subsequent change of route. Pilots must ensure the waypoints sequence, depicted by their navigation system, matches the route depicted on the appropriate chart(s) and their assigned route;
• Verify the aeroplane’s RNAV system is available, operating correctly, and the correct airport and runway data are loaded, prior to commencing take-off;
• Note that the FMS navigation databases are expected to be current for the duration of the flight. If the AIRAC cycle is due to change during flight, an additional navigation database with the data of the next cycle shall be uploaded. Current and next FMS navigational database must not be switched during the flight;
• Not fly an RNAV SID or STAR unless it is retrievable by route name from the FMS navigation database and conforms to the charted route. However, the route may subsequently be modified through the insertion or deletion of specific waypoints in response to ATC clearances. The manual entry or creation of new waypoints by a manual entry, of latitude and longitude or Place-Bearing-Distance values, is not permitted. Additionally, pilots must not change any RNAV SID or STAR database waypoint type from a fly-by to a flyover or vice versa;
• Extract, whenever possible, RNAV routes in the en-route domain from the database in their entirety, rather than loading individual waypoints from the database into the flight plan. However, it is permitted to select and insert individual, named fixes/waypoints from the the navigation database, provided all fixes along the published route to be flown are inserted. Moreover, the route may subsequently be modified through the insertion or deletion of specific waypoints in response to ATC clearances;
• Cross-check the cleared flight plan by comparing charts or other applicable resources with the FMS textual display and the EFIS map display, if applicable. If required, the exclusion of specific navigation aids should be confirmed. At times, pilots may notice a slight difference between the navigation information portrayed on the chart and their navigation display. Differences of 3 degrees or less may result from the equipment manufacturer’s application of magnetic variation and are operationally acceptable;
• Verify that the correct terminal route has been loaded, prior to the arrival phase. The active flight plan should be checked by comparing the charts with the EFIS map display (if applicable) and the FMS textual display. This includes confirmation of the waypoint sequence, reasonableness of track angles and distances, any altitude or speed constraints, and, where possible, which waypoints are fly-by and which are the flyover. If required by a route, a check will need to be made to confirm that updating will exclude a particular navigation aid. A route must not be used if doubt exists as to the validity of the route in the navigation database;
• Note that route modifications in the terminal area may take the form of radar headings or »DIRECT TO« clearances and the flight crew must be capable of reacting in a timely fashion. This may include the insertion of tactical waypoints loaded from the database. Any published altitude and speed constraints must be observed.