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CNS/ATM Steering Group WGS-84 P-RNAV issue Pierre Gayraud Thales Avionics Brussels 01-02/07/2008. Issue : Some States Publish P-RNAV procedures Do not use WGS-84. Regulation TGL 10 : « All routes/procedures are based upon WGS 84 co-ordinates » (ASSUMPTIONS 4b) PANS-OPS
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CNS/ATM Steering GroupWGS-84 P-RNAV issuePierre GayraudThales AvionicsBrussels 01-02/07/2008
Issue : • Some States • Publish P-RNAV procedures • Do not use WGS-84 Aéronautique
Regulation • TGL 10: • « All routes/procedures are based upon WGS 84 co-ordinates » (ASSUMPTIONS 4b) • PANS-OPS • « Waypoints and DME station coordinates must meet the WGS-84 requirements »Chapter II-3-2 (RNAV ARRIVAL AND APPROACH PROCEDURES BASED ON DME/DME): • Annexes 4, 11 and 15: Accuracy • En-route navaids and fixes, holding, STAR/SID points: . . . . . .. . . . . 100 m • Final approach fixes/points and other essential fixes/points comprising the instrument approach procedure . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . 3 m • PBN Manual • All routes must be based upon WGS 84 (all Nav Specs) • RNP 4 Nav Spec only • WGS-84 or an equivalent earth reference model must be the reference earth model for error determination. • If WGS-84 is not employed, any differences between the selected earth model and the WGS-84 earth model must be included as part of the path definition error. • Errors induced by data resolution must also be considered. Aéronautique
A number of countries do not use WGS 84 • China: « For the time being, WGS-84 has not been adopted » (AIP GEN 1.7-5 §3.6.4) • Russia: « World Geodetic System-1984 (WGS-84) is not applied as the horizontal reference system. The National Geodetic System -1942 is used » (AIP GEN 1.7 §3.7.1) • Belarus… • What operators should consider? • P-RNAV operations are not possible in countries non WGS 84 compliant? • P-RNAV operations are possible under the condition they check the difference between the reference systems are smaller than TBD (for example 0.1 RNP = 185 m)? • … • => Operators need guidance to cope with this situation Aéronautique