RNAV Approaches

New: RNAV Approaches Leaflet (PDF)

Instrument approach procedures using RNAV with GPS positioning have been possible since 1998 when ICAO published the Basic GNSS approach design criteria. Certain ECAC states introduced GPS approach procedures based upon these criteria and used the JAA TGL 3 guidance material to develop national regulations for certification and operational approval.

The JAA subsequently decided that TGL 3 provided insufficient guidance on the subject and proposed to develop a new guidance document (AMC 20-27). In 2001 ICAO published procedure design criteria for RNAV approaches using Barometric VNAV and certain States have conducted trials based upon these criteria. The RNAV/Baro VNAV criteria are based upon a lateral navigation performance associated with RNAV (GNSS) or RNP 0.3 and a vertical navigation performance based upon the use of Barometric inputs with a VNAV functionality in the airborne system.

AMC 20-27 addresses RNAV approach operations down to LNAV/VNAV minima as well as RNAV approach operation down to LNAV. An additional document, AMC 20-26 covers RNP AR operations within terminal airspace, including RNP AR approach operations down to RNP 0.1. Following EASA Decision 2009/019/R on 23^rd December 2009, AMC 20-26 and 20-27 are available for applicants.

EGNOS becomes operationally available in 2010 and will be used to support RNAV approach operations down to LPV minima; once the service provider has been certified under the European Single Sky Regulations. ICAO has also published design criteria for SBAS approaches and EASA is preparing AMC 20-28 to include LPV operations.

ICAO have recommended that States plan the implementation of approach procedures with vertical guidance (APV) for all instrument runway ends, either as the primary approach or as a back-up for precision approaches by 2016. This recommendation covers the publication of either or both RNAV approach down to LNAV/VNAV and LPV minima (also called respectively APV Baro and APV SBAS)

EUROCONTROL is working on the development of a Generic Safety Case covering RNAV approaches (LNAV and LNAV/VNAV) and LPV operations. . It has developed an OCA/H Estimator tool (MET Tool) to assist States in deciding which approach variant to implement at any given airport.  In addition a tool has been developed which can generate the Final Approach Segment (FAS) data-block for SBAS Approaches, compute the relevant CRC and generate an electronic file of this FAS DB. Finally EUROCONTROL, the FAA and ICAO has recently agreed that EUROCONTROL will be the focal point in Europe for SBAS channel number allocation useful for the publication of RNAV approach down to LPV minima. This is an interim solution until the ICAO puts in place a unique and world-wide solution.

Note: “RNAV approach” is the name of the chart for approach procedures which comply with ICAO PBN navigation specifications for RNP Approach (RNP APCH). In the near future, the ICAO PBN Manual will include a 3^rd navigation specification for RNP APCH in addition to the two already existing:

- RNP APCH without vertical guidance (down to LNAV minima),

- RNP APCH with barometric vertical guidance (down to LNAV/VNAV minima) and

- RNP APCH with vertical guidance based on SBAS (down to LPV minima).