Hi, I’m a new subscriber, and have a question about how to interpret some of the different approach terminology used on the Jeppesen charts:
RNAV GNSS = GPS with both lateral and vertical guidance?
RNAV RNP = same as above but requiring more accuracy?
RNAV RNP AR = Authorization Required, equipment of highest accuracy?
For example, Toronto City Centre Billy Bishop Airport (CYTZ) has both RNAV (GNSS) and RNAV (RNP) approaches, which I know both use GPS - but what does the difference in GNSS and RNP signify? Is the difference the accuracy required of the equipment?
The RNAV (RNP) approach is listed as “RNAVgps” in MSFS and the new WT G1000 NXi will capture the Glide Path for this type of approach.
The problem in the MSFS standard data format (which will be used by the WT G1000NXi) is, that there are a view missing approach-types and/or approach types which are not specific in detail, like RNAV RNP … the only offer RNAV approaches. So there is no other way, to “translate” such approach-types into a more or less fitted type to avoid to remove it completely from the database.
The wording “RNAVgps” comes from the WT G1000NXi and are not part of our data.
But all in all, you have understood/explained it perfect but I´m honest, I´m not a real-world pilot so that´s only my interpretation also.
If it helps anyone else understand, it looks like this is the root of the confusion:
The FAA uses approach name titles with “RNAV (GPS)” to say “Area Navigation, using GPS”. That’s clear, but it ties the chart to a specific signal type or equipment type, and over time equipment and signal sources can evolve or change.
So the ICAO wanted to define approaches based on accuracy minimums independent of equipment. So if your plane is capable of staying within 0.30 nm of a course, and meets the performance specifications regardless of what specific equipment or signals, then it can fly the approach. Even if technology changes, the specifcations of the approach stay the same.
So as of December 2022, the ICAO has said approach charts RNAV (GPS) and RNAV (GNSS) will be named “RNP”. And for the more restrictive “Authorization Required” approaches, RNAV (RNP) will be renamed “RNP AR”.
However, the FAA is keeping the US RNAV (GPS) and RNAV (RNP) naming conventions to avoid the cost of renaming thousands of charts.
It’s unclear if the names of approaches available in the MSFS UI will reflect the new naming for international airports or not. I’ve asked but I think it depends on the data supplied to them (by NavBlue, I think?).
