Question regarding the coding of vertical guidance for RNP/RNAV approaches

[norman99]

Hi, I have some questions regarding RNP/RNAV approaches in MSFS when using Navigraph NavData.

Using Lockhart River (YLHR) as an example, it has 3 RNP approaches available, RNP RWY12, as well as RNP Y & Z RWY 30. The runway 12 approach includes both LNAV & LNAV/VNAV minima, whereas the RNP Z RWY 30 as LNAV minima only, and the RNP Y RWY 30 LNAV/VNAV minima only.

Using the updated WT/Asobo GNS530 (which are now LPV, LNAV/VNAV and LNAV+V capable), all three approaches are listed simply as RNAV approaches (should they be RNP?), and only ever activate in LNAV mode. At no point is vertical guidance available. I assumes that the approaches with LNAV/VNAV minima should provide vertical guidance. Is this due to the coding in the NavData or something else?

This also leads me to another question. Some LNAV only approaches are able to be flown with advisory vertical guidance with LNAV+V, when using an appropriate WASS GPS unit. With the new implementation of LNAV+V in the WT/Asobo GNS530, should vertical guidance be available for all RNP/RNAV approaches, or is it dependant on the individual approach coding?

[norman99]

Well, you can disregard my question above, as it was answered on the MSFS forum. It seems different regional capabilities are modelled in the new WT/Asoobo GNS units. I knew SBAS isn’t available in Australia, but never knew it was simulated too.

The GNS units (as in real life), can only provide RNAV vertical approach guidance if there is SBAS coverage, which Australia does not yet have. The GNS units, unlike later units like the G1000, will not give +V in these scenarios either, and they are not certified for baro-VNAV (so no VNAV vertical guidance for RNAV without SBAS).