No. RNP is not just another name for GPS. It is a slightly different tech.
In this context the approach is exactly the same. Using the same technology. Yes RNP is a different standard from RNAV. But the “tech” is the same.
It is a bureaucrat’s dream. We chart the exact same procedure as RNAV (GPS).
placido wrote:
on my Zurich RNAV (GNSS) RWY 14 plate there is no EGNOS channel reference why does it appear on the RNP plate?
Because that approach is not an SBAS (EGNOS) approach, doesn’t have LP/LPV minima (only LNAV, LNAV/VNAV). Therefore, there’s no EGNOS channel number.
USFlyer wrote:
No. RNP is not just another name for GPS. It is a slightly different tech.
It’s not even “different tech”, is comparing apples to, well, orchards…
ICAO wants to go away from the traditional way of thinking about specific navigational aids (NDB, VOR, GPS, INS etc.) and instead use the concept of Performance-Based Navigation (PBN). The idea is that a flying in a particular airspace, or along a particular route or on a particular approach should no any longer require particular navigational aids. You could use any navigational aids as long as the nav system in the aircraft is certified to have the required performance.
PBN navigation systems are divided in two groups: RNAV and RNP (Required Navigational Precision). As USFlyer pointed out, the difference between the two is that RNP requires on-board integrity monitoring while RNAV does not.
Within both the RNAV and RNP groups, there are different “navigation specifications” that call for different “performance”. “Performance” in this context is a combination of navigational accuracy and nav system functionality. One such specification is RNAV 5 which is essentially the same thing as B-RNAV, another one is RNP APCH which is what you need for a regular RNP approach.
Thus when RNAV or RNP is specified you can use any navigational aid (e.g. GPS, GLONASS, Galileo, INS, VOR/DME, DME/DME etc.) as long as the nav system in the aircraft can achieve the required performance.
So, while this might possibly be a “bureaucrat’s dream”, the point is not to make bureaucrats happy, but to attempt to make a certification framework which is independent of future technological advances in navigation systems. E.g. if eLORAN should ever become a widely used back-up system for GPS, then you could at once fly every RNP approach using eLORAN instead of GPS as long as the nav system achieves RNP APCH performance.
Yes but for light GA, if you can fly a GPS approach now, you can fly it when it is branded RNP. RNP is different but the differences have almost no practical impact on your typical PA28 flying an LPV into Calais.
More complex is enroute and terminal RNP such as RNP1 which may require approvals and may not be authorised for existing equipment.
Does that mean that my LPV approved system (Avidyne, GNS430W) is approved for RNP aswell?
It should be. Check for RNP APCH in your documentation. Alternatively if it mentions compliant with AMC20-28 that is enough for LPV RNP APCH.
From AMC20-27 (for LNAV approaches) -
8.3 Existing Installations
… An existing statement in the AFM that indicates the aircraft is approved:
to perform RNP 0.3 GNSS approaches or, for instrument approaches including a specification of RNP GNSS capability that
meets RNP 0.3 is considered acceptable for lateral performance.
NCYankee wrote:
So GPS was the name for approaches, no that is not good enough, they are RNAV (GNSS), no that is not good enough, RNP. Finally the FAA grew a pair and said enough is enough, we are not renaming the 13000+ approaches. In the US, they will remain RNAV (GPS). Before it is all over, ICAO will have a dozen new names that mean precisely the same thing, glad we are not playing that game any more.
While I sympathise with the frustration, if you’re going to divide PBN ops into categories without on-board monitoring and alerting (RNAV) and with on-board monitoring and alerting (RNP), then GPS approaches are and always have been a flavour of RNP. But it does lead to some difficulties with terminology migration. For those less familiar with the issue than NCYankee…
There are two specs, RNP APCH (normal ones, flyable with standard GPS equipment) and RNP AR APCH (special ones, which most GA aircraft will never be equipped to fly).
Here’s the ICAO spec from the amendments proposed in State Letter 24 2013, which is hardly a model of clarity.
1.4.2.2 Until 30 November 2022, approach charts depicting procedures that meet the RNP APCH navigation specification criteria shall include the term RNAV(GNSS) in the identification (e.g. RNAV(GNSS) RWY 23) or, alternatively, as described in 1.4.2.3.
1.4.2.3 From 1 December 2022, charts depicting procedures that meet the RNP APCH navigation specification criteria shall include the term RNP in the identification (e.g. RNP RWY 23). …
1.4.2.4 Until 30 November 2022, charts depicting procedures that meet the RNP AR APCH navigation specification shall include the term RNAVRNP [RNP is usually written as a suffix] in the identification (e.g. RNAVRNP RWY 23) or, alternatively, as described in 1.4.2.5.
1.4.2.5 From 1 December 2022, charts depicting procedures that meet the RNP AR APCH navigation specification shall include the term RNP in the identification with a parenthetical suffix (AR). (e.g. RNP RWY 23 (AR))
The Sylt plate is an example after 1.4.2.3, where the DFS have renamed their charts earlier than the 2022 deadline. The Avidyne manual quoted by Placido is referring to approaches using the old terminology of 1.4.2.4.
IMHO the RNP is not correct in this case as indeed PBN specifies for on board performance monitoring. This is not the same as having just an annunciator…This requires NAV system Monitoring etc..So there we are with the IAC harmonisation… 
Look at EBAW they have new almost the same IAC with LPV but its called GNSS (RNAV) RWY 11.
One side note LPV has the same minima as LNAV 
bookworm wrote:
1.4.2.3 From 1 December 2022, charts depicting procedures that meet the RNP APCH navigation specification criteria shall include the term RNP in the identification (e.g. RNP RWY 23). …
The US has declined the invitation to rename its approaches and will not comply.
