Rnp and Ils, Vor approaches

[Speed Freak]

i recently went for an interview where i was asked a question:
what is the RNP value required for an ILS, VOR and a NDB approach?

i fly the airbus A-320 and this question confused me a bit and i stated that there is no relation between RNP and an ILS approach.

however, i was told that this is not the case and apparently there are RNP values of .3, .5 and .6 for the approaches respectively. i have not been able to find these values in any airbus specific or general literature on RNP.

However, on consultation with a few friends flying the Boeing 777, i found that these values are mentioned in their SOP. (the person asking the questions was a 777 Examiner).

can someone please clarify with source. the interview was a navigation interview for ATPL and feel it was not fair to be asked a 777 specific question. (my friends on the 737 say there is no such thing in their SOP).

however i wouldnt mind being contradicted.

thank you.

[STBYRUD]

Hm, for our 737s the RNP for all approaches is 0.3... Beats me where that comes from though!

[Avenger]

For Boeing, RNP Requirements are detailed in FCTM, and for Airbus in Instructor support section on GPS Primary description, although again mentioned in the training materials on approaches and NAV ACCURACY.
The whole RNP subject is also detailed in Operations Manual B for most companies, covers en-route, terminal and approach RNP requirements.
General rule is " Unable Reqd Nav Perf" or " Nav Accuracy Low" you are stuffed.

[aterpster]

Speed Freak:

however, i was told that this is not the case and apparently there are RNP values of .3, .5 and .6 for the approaches respectively. i have not been able to find these values in any airbus specific or general literature on RNP.

RNP = Required Navigation Performance. ILS, VOR, or NDB are not predicated on performance-based navigation.

Having said that, I can see the value of expressing an RNP value for VOR or NDB approaches if they are authorized for RNAV overlay flight of the final approach segment; i.e., "VOR or GPS Runway36," for example.

But, for ILS it makes no sense at all because ILS, per se, must be used to fly the ILS final approach segment and, in the U.S. at least, the ILS intermediate segment as well.

[Denti]

RNP values for non precision approaches is of course something kinda old as many airlines use LNAV/VNAV to fly them for quite a long time (we use LNAV for more than 15 years now, VNAV for 10+ years and only recently, 5 years ago, switched to IAN), of course with full approval by the relevant authority. But same as others i fail to see the relevance for an ILS as long as only the ILS is meant. I can understand a RNP value for initial approach and missed approach, but not the final or intermediate approach.

[LLLK]

VOR, NDB and ILS are 'conventional' approaches. There is no associated RNP value. The RNP values only apply to RNP APCH (charted as RNAV(GNSS)), where the final approach segment is always 0.3 and all the other segments are 1.0, and RNP AR APCH (charted as RNAV(RNP)) where any leg can be as low as 0.1.

[Speed Freak]

RNP = Required Navigation Performance. ILS, VOR, or NDB are not predicated on performance-based navigation.

thats what i said and even went on to explain that suppose my rnp falls below 0.3 does that mean i cant even do an ils approach. how do i land then:confused:

told them of the 320 where if my nav accuracy falls below 1 i just switch to raw data and continue. he wasnt convinced at all.

Having said that, I can see the value of expressing an RNP value for VOR or NDB approaches if they are authorized for RNAV overlay flight of the final approach segment; i.e., "VOR or GPS Runway36," for example.

i hope he was talking about this but i doubt it.

RNP Requirements are detailed in FCTM, and for Airbus in Instructor support section on GPS Primary description

will try to refer to them

RNP values for non precision approaches is of course something kinda old

1 nm as per 320 sop.

[aterpster]

LLLK:

RNP AR APCH (charted as RNAV(RNP)) where any leg can be as low as 0.1.

True of initial, intermediate, or final. Feeder cannot be less than 1.0. Missed approach can start out at value of final segment, but must increase incrementally ("telescope" expansion) to RNP 1.0. Incremental increases are predicated on presumed IRU performance assuming failure of GPS in the final segment.

For aircraft without at least one IRU minimum leg performance is 0.3, and missed approach must be RNP 1.0 or greater.

[mustafagander]

Speed Freak,

The simple (and most correct) answer to this RNP thingo is that, for the approaches listed, there is no such thing because they do not depend on GPS or any form of RNav.

AFAIK most RNav approaches have a limit of 0.2 for the final approach segment just for interest.

[Avenger]

Spead Freak,

I would be very cautious of some of the advice here!

Approach Requirements Relating to RNP:

" With appropriate operational approval, approaches requiring RNP alerting may be conducted in accordance withe the following provisions:"

The source of information I suggested then expands the subject:ok:

[LLLK]

Aterpster:

Agreed - the RNP(AR) was really a brief aside comment to the main question - where the answer is simple - ILS, VOR and NDB (in fact all conventional NPAs) have nothing to do with RNP!:ugh:

[engfireleft]

Speed freak

Your understanding is exactly right. RNP values have absolutely nothing to do with any conventional navaid based procedures. Although we use managed nav to fly non-precision approaches, the primary reference is still the navaid itself which must be tuned, identified and displayed. In the case of an ILS you are actively tracking the radio beam itself.

Think of it this way, if an RNP were required how is it that a steam aircraft that has no RNAV capability whatsoever is able to fly the approach? In the case of the Airbus, both FMGC's could completely fail and you are still perfectly able (and legal) to fly any conventional navaid based procedure.

Whoever interviewed you does not know their stuff as well as you do.

[FlightDetent]

told them of the 320 where if my nav accuracy falls below 1 i just switch to raw data and continue. he wasnt convinced at all.


The way you explain the question, I would give similar answer. EPE is relevant for NAV use, when out of limits use raw data if it helps. When on raw data mode such as GS/LOC, both actual EPE and database coded accuracy limit are irrelevant.

FD (the un-real)

[aterpster]

mustafagander:

AFAIK most RNav approaches have a limit of 0.2 for the final approach segment just for interest.

Most have 0.3 as the performance value for the final approach segment. LPV is quite different, as is RNP AR.

[FE Hoppy]

Not applicable.

The guy asking the question was talking *6576çç???

[Denti]

As long as you use raw data as primary source of navigation there is no RNP, agreed. However, if you have the approval to fly non precision approaches without the need to tune and use the real nav source at all and without the need for an existing RNAV overlay approach, would you still fly it without any RNP?

[Avenger]

With respect to the contributions, the interviewer asked a question for which there is a published answer in both Airbus and Boeing manuals, they are simply probing your understanding of the systems as installed and operations of advanced naviagtion systems. I would not tell the Chief Pilot he was talking S,,,t, I would conceed I didn't know... simple as that. The concept using raw data as the primary source is not normal in airline transport operations.

[engfireleft]

There is nothing in any Boeing or Airbus manual I've ever seen that says you must meet an RNP criteria for conventional navaid based approaches, nor is there a regulatory requirement. And there's a very good reason for that. The two have absolutely nothing to do with each other.

Only if you are conducting an RNAV procedure (SID, STAR or Approach) are you required to comply with the RNP value for that procedure. Non-RNAV procedures have no RNP value to maintain because the procedure is done in reference to a navaid.

The two are mutually exclusive.

One is done with reference to the navaid only. And the other is done referencing the RNAV capability of the aircraft independent of ground based navigation aids.

Apple and oranges.


"The concept using raw data as the primary source is not normal in airline transport operations."

Are you suggesting airline transport operators never conduct ILS, VOR or NDB approaches then? Because raw data on all of those procedures is the primary source?

[FE Hoppy]

With respect to Avenger could you give references please?

The question specificly asks for ILS, VOR and NDB for which there are no RNP values required, anywhere in the world.

[aterpster]

FE Hoppy:

The question specificly asks for ILS, VOR and NDB for which there are no RNP values required, anywhere in the world.

It's a matter of FMS "overlay" authorization for VOR or NDB, not a RNP specification for the procedures in general.

[engfireleft]

An overlay approach shares the plate and minimums with the VOR or NDB procedure, but beyond that it has nothing to do with the VOR or NDB. If you do a GNSS overlay approach you are doing an RNAV approach, which you must be trained, equipped and authorized to do.

The actual VOR or NDB could have been dynamited into oblivion years before and it doesn't matter, because you aren't flying a VOR or NDB approach.

[Avenger]

Boeing FCTM Page 193 section on Non ILS Approaches and also the section relating to ILS approaches " Approach Requirements Relating To RNP" values are tabulated. Boeing are certified to use the FMS as primary source of naviagtion provided the RNP values are met.. Interesting stuff this..

[engfireleft]

Right Avenger. Boeings, Airbus's, Embraers, Bombardier's, Gulfstreams, many aircraft are certified for RNAV operations. That doesn't mean the crews are though.

For commercial operations an operations specification must be obtained from the regulator before conducting any kind of RNAV approach, and that ops spec will not be issued unless the aircraft is certified and the crews are properly trained and checked on RNAV procedures.

What does any of that have to do with ILS, VOR or NDB approaches?

[Denti]

engfireleft, an overlay approach is simply a normal RNAV approach, which uses a specified RNP.

Completely different from that however is the authorization to fly any non precision approach, without the need for any existing RNAV approach being published, by FMC guidance alone. The 737 FCOM even tells us about raw data monitoring during non ILS/GLS approaches "For airplanes with two operational FMC, two IRS and two GPS receivers (or two DME receivers if GPS updating is not available), or if the FMC is RNP/ANP capable, raw data monitoring is not required." Which means only one RNP/ANP capable FMC is enough to fly non precision approaches without using any raw data source related to the procedure. However we do have to keep within certain RNP limits, since we are no longer able to check with raw data if we are within the limits of the procedure.

Of course you need to train the crews for that, same as you train them to fly ILS, GLS or RNAV approaches.

The approach in itself does not have a RNP value, however if you are authorized to fly it without using raw data as primary means of navigation you most probably have to conform to a certain RNP. The values and certification process are of course something to check with both the local regulator and the OEM.

[engfireleft]

This is the confusion we have generated in the last 20 years by using the FMGS to fly non-precision approaches.

To reiterate: If you are flying a conventional non-precision approach i.e. LOC, VOR or NDB, then the navaid must be tuned, identified and displayed at all times and it is your primary reference.

We can and do use the FMGS for guidance, meaning using it to steer the airplane, but at all times the primary reference is the navaid stated in the procedure you are flying. That is a regulatory requirement everywhere in the world and there is no relief from that. If the raw data shows you going off track, then you have to do something different to bring it back. Nowhere do you reference RNP because your reference is the navaid.

If your only reference is the FMGC, then you are doing an RNAV approach and they all, without exception, have an RNP attached. Usually it is 0.3 for basic RNAV, but there are RNAV AR and RNP approaches that are more stringent. Conventional navaids are not part of the RNAV picture in any way with the exception of critical DME's in the case of RNAV 1 SID's and STAR's if your aircraft is not GPS equipped.

I can't make it any simpler than that. If you are doing an ILS, VOR or NDB the navaid is your primary reference and has to be there by regulation. The use of FMGC's for guidance in that case is a technique, but doesn't negate the requirement for the navaid.

[aterpster]

enginefireleft:

I can't make it any simpler than that. If you are doing an ILS, VOR or NDB the navaid is your primary reference and has to be there by regulation. The use of FMGC's for guidance in that case is a technique, but doesn't negate the requirement for the navaid.

You, and Denti in the post immediately above your's, are in direct contradiction. My vote goes with Denti.:)

[engfireleft]

Ok, how about this?

Do you agree that an overlay approach is an RNAV approach? If yes, then:

Do you agree that if a VOR is unavailable but there is an overlay you can still fly the approach using the overlay (RNAV)? If so, then:

Do you agree that if the VOR is unavailable and there is no overlay, you may not fly the approach, since there is no RNAV procedure?

If you understand all that, and understand that an RNAV has as much relationship to a VOR approach as an ILS does, what is this discussion about? You can do RNAV, or ILS, or VOR, or NDB. You can't do a combination of them.

ILS requires a functioning ILS transmitter
VOR requires a functioning VOR transmitter
NDB requires a functioning NDB transmitter
and RNAV requires a specific navigation performance be met along with crew qualification etc.

[Denti]

Sadly it is not as simple as that, and additionally a lot depends on local regulations. Lets think about some tiny airport out there that has only one IFR approach, lets say it is a VOR approach. No RNAV approach, no ILS, GLS or MLS.

Now, according to what we are allowed to use we would set up the VOR approach in the FMC and fly it using IAN which makes it look and act like an ILS, autopilot or not and flight director or not doesn't matter, i can fly it either way. However we do not tune the VOR as we are not required to do that, perhaps set up the approach for our alternate, or some nav aids used during the missed approach or simply forget about it all since we do not need to tune anything, we just have to make sure there is no ILS tuned, but that is simply an autoflight system restriction (approach mode would try to intercept the tuned ILS instead of the IAN approach if one is tuned).

The VOR on the ground has to be serviceable of course or ATC could not clear us for the approach. But we won't use it, except as backup, since all we need to fly the VOR approach is one FMC, and we got two of those. Now, how do we now that we are still within the limits of the approach? By using a generic RNP of 0.3 which is database coded into the approach. The approach in itself does not have any RNP, however if you want to fly it using the FMC as sole guidance you have to use an RNP and it is part of your companies approved procedures and therefore part of the AOC.

The need to tune, identify and display the navigation source for a non precision approach is not there anymore. That bit of legislation may not have reached your company or country yet, but it will. The aircraft we use are certified for it for quite some time now, the 737 since it turned into the NG.

[engfireleft]

You don't need any FMG to fly the approach because you have the VOR.

If you use the RNP as sole guidance you are doing an RNAV approach, and must comply with all of the requirements therein.

You should probably get your hands on an ICAO PBN manual. It sounds to me like your company is doing RNAV approaches without RNAV approval and without complying with any RNAV requirements.

To use RNAV as a reference the approach must be encoded in the database as such, the tracks and distances must be checked, and nothing from the FAF in can be changed laterally for LNAV, or vertically if you're going to use VNAV. GNSS is required for any 0.3 approach (for now anyway) and RAIM must be confirmed before completing the procedure. There must also be an alerting function in the airplane that warns you when GPS is lost or the EPU exceeds the RNP for the approach.

Do you comply with any of this when you do your VOR approach using the FMGS as the only reference?

[galaxy flyer]

Guys,

There exists a breach between the FAA and ICAO on this issue. Initially, when the FAA started the "GPS overlay" approvals, they required the underlying approach navaid to be tuned and monitored. This requirement went away in FAA World sometime ago, if the FMS meet TSO-specific requirements as an approach aid, the need to tune, monitor or even to have the underlying navaid was eliminated. The ICAO and EU countries, as I understand it, have kept the requirement to tune and display the underlying navaid, unless it is a RNAV approach.

In my plane, we can fly any NPA, using FMS approach, without the navaid tuned or displayed, as long as "APP" or "GPS APPR" is annunciated before the FAF. This is common in the US, but not so in many regulatory regimes.

This from FAA AC 90-94, 1994

(1) Phase I. This phase ended in February 1994, the date when
the FAA declared GPS operational for civil operations.
(2) Phase II. This phase began on February 17, 1994 when the FAA
declared the system suitable for civil operations. Certified GPS
equipment can be used as the primary IFR flight guidance to fly an
overlay to an existing nonprecision approach without actively
monitoring the applicable navaid(s) which define the approach being
used. However, the underlying ground-based navaid(s) required for the
published approach must be operational and the associated avionics
must be installed and operational. The avionics need not be operating
during the approach if RAIM is providing integrity. Pilots can tell
that Phase II applies because "GPS" is not included in the title of
the approach.
(3) Phase III. Phase III began April 28, 1994, when the first
instrument approach procedures were published to include "or GPS" in
the title of the published approach procedure. Neither the aircraft
traditional avionics nor the underlying ground station navaid(s) need
be installed, operational, or monitored to fly the nonprecision
approaches at the destination airport. For GPS systems that do not use
RAIM for integrity, the ground-based navaid(s) and the airborne
avionics that provide the equivalent integrity must be installed and
operating during the approach. For any required alternate airport, the
traditional ground-based and airborne navigational equipment that
defines the instrument approach procedure and route to the alternate
must be installed and operational.

This authorization is expressly limited to FAA regulated airspace. Also, the TERPs standard used to designed the approach was that for the ground-based navaid, not RNAV. So, one can fly a VOR approach, with approved equipment, as an FMS approach without use of the ground-based navaid in US airspace. It will not be an RNAV approach, it will be a VOR standard approach flown using FMS.

GF

[Zeffy]

AC 90-94 was cancelled about two years ago, superseded by AC 90-105 (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/742a9eb4802111b48625754e005fe2e7/$FILE/AC90-105.pdf).

[Denti]

The ICAO and EU countries, as I understand it, have kept the requirement to tune and display the underlying navaid, unless it is a RNAV approach.

The ICAO maybe, the EU has changed things as well.

Of course you can fly it using the old fashioned procedures by tuning the VOR, calculating your rate of descent (drive and dive is not allowed anymore) and flying it in VORLOC using V/S. But that is not necessary anymore of course. And of course we are certified for RNPs down to 0.3 with either GPS or only DME/DME and down to CAT I (currently flying CAT IIIb tests) using GBAS or anything inbetween.

[galaxy flyer]

Zeffy

Yes, it was and AC 90-105 doesn't address the issues of AC 90-94 directly, but state, "However, previous approvals under these two ACs (AC 90-94 and AC 90-97) are still valid for the operations and conditions stated."

I posted the reference to point out the historical background as to how the use of GPS and FMS evolved.

GF

[aristoclis]

1. In which european countries exactly is it allowed to fly VOR or NDB approaches without referring to the basic navaid? (assuming FMGC is certified to fly NPAs in nav mode)

2. Even if what Denti says is right, the instructor mentioned RNP for ILS approaches as well, so I don' t think all these make any sense.

:rolleyes:


My vote goes for engfireleft

[galaxy flyer]

There is simply no way RNP relates to ILS. Unless one forces the issue and tries to apply RNP calculations to LOC accuracy, a bit like calling MNPS RNP 12.6. If track spacing works out to a bit under 60 nm, then 95% of the time the plane must be within 12.6 nm of actual position because it must be within 60nm 99% of the time.

GF

[changer]

The concept using raw data as the primary source is not normal in airline transport operations.
Not sure what you're thinking here, but it's misleading to say the least. Every autopilot uses LOC and GS for autolands. The missed approach procedure may be flown with LNAV, which may require a RNP, however



I would be very cautious of some of the advice here!


Now I'll agree with you there, Avenger!

[Kirks gusset]

Changer, I am not sure how autoland has creeped into this thread, as you are aware, not all ILS end in autoland, are you suggesting the aircraft cannot land without a traditional Glide slope and localiser signal? Our caompany procedure is to fly all approaches using the FMS as the primary source of nav if the RNP is achieved and " where available, monitor raw data" , this is referred to in the Boeing FCTM. I believe, Avenger was referring to the orignal question, and the fact that generally, it is not a good idea to tell the interviewer they are talking rubbish, when clearly, as demonstrated by the answers here, he/she had a vaild question.

[aterpster]

kitks gusset:

Our caompany procedure is to fly all approaches using the FMS as the primary source of nav if the RNP is achieved and "where available, monitor raw data"

Because you state "fly all approaches using FMS as the primary source..." does this include ILS? If so, what do you use to replace the ILS glideslope?

[engfireleft]

"Our caompany procedure is to fly all approaches using the FMS as the primary source of nav if the RNP is achieved and " where available, monitor raw data" , this is referred to in the Boeing FCTM."

If you are conducting an approach using the FMS as the primary source of navigation you are doing an RNAV approach. The requirements for doing those are pretty much universal and becoming more refined as time goes along and the world converts to PBN. You're suggesting your company does conventional NPA's and if the signal is not available, no problem, we'll just use the FMS.

If you don't mind my asking, what country is your company based in? Also if you don't mind saying what company is it?

[galaxy flyer]

I beg to differ, engfireleft, if the approach is on a ground-based navaid (for the pendants: VOR, VOR/DME, TACAN, NDB, that is non-LOC) it is an FMS approach flying an overlay. The approach is drawn to TERPS, PANS-OPS standards for the terrestrial navaid, not to RNAV or RNP standards. There is no specified RNP because it is a conventional approach flown on the FMS. the crew must be trained appropriately, the database current and used. The Canadian-built and trained business aircraft is flown and trained thusly.

GF

[changer]

are you suggesting the aircraft cannot land without a traditional Glide slope and localiser signal?
If we're doing an ILS approach, then Yes!

Every ILS, autoland or not, the airplane does the exact same until you hit the disconnect button. Afterall, it doesn't know if/when you're going to disconnect.

Boeing airplanes have two different buttons to hit to commence the approach, and which button you hit depends on what kind of approach you're doing. If you're doing an ILS approach (autoland or not) you hit the APProach switch. That connects the autopilot and/or Flight Director to the LOC and GS. If you're doing a RNAV approach, you hit the LNAV button, which does NOT connect the AP/FD to the LOC/GS

[Denti]

Boeing airplanes have two different buttons to hit to commence the approach, and which button you hit depends on what kind of approach you're doing. If you're doing an ILS approach (autoland or not) you hit the APProach switch. That connects the autopilot and/or Flight Director to the LOC and GS. If you're doing a RNAV approach, you hit the LNAV button, which does NOT connect the AP/FD to the LOC/GS

I beg to differ, newer boeings do it all with the APProach button.

[aristoclis]

Irrelevant. Airbus does it all with the approach button as well (for those who beg to differ), but in the case of ILS it tracks the beam, in the case of NPA (except LOC) it goes to FINAL APP (LNAV/VNAV). And in that case monitoring of raw data for non RNAV approaches (navaid and baro altitude) is mandatory (still waiting for the countries where it's not).
Again all this is irrelevant. The interviewer' s question still makes no sense.

:ugh:

[engfireleft]

I beg to differ, engfireleft, if the approach is on a ground-based navaid (for the pendants: VOR, VOR/DME, TACAN, NDB, that is non-LOC) it is an FMS approach flying an overlay. The approach is drawn to TERPS, PANS-OPS standards for the terrestrial navaid, not to RNAV or RNP standards. There is no specified RNP because it is a conventional approach flown on the FMS. the crew must be trained appropriately, the database current and used. The Canadian-built and trained business aircraft is flown and trained thusly.




A bit of history and explanation. If you don't want to read it skip right to the end.

When regulators first realized GPS could be used to fly an approach they invented "GPS" approaches. There were very few of them around however so as a quick, cheap and easy means of getting more of them out there they created "overlay" approaches. These used existing NPA approaches and effectively bolted an RNAV procedure over top. The design criteria was as for a conventional approach as well as the minimums. We were just permitted to use the RNAV capability of the aircraft to fly it. These types of approaches are disappearing as proper standalone RNAV approaches are built to replace them.

The naming convention for RNAV approaches used to be all over the map. RNAV approaches are all called "RNAV" now because under the Performance Based Navigation (PBN) concept it is recognized that any system that meets the performance requirement of the approach is acceptable. That's why GPS approaches are disappearing. Some may specify GNSS as a requirement but the type of approach is still titled "RNAV". Even further some approaches require specific additional RNP values and you will see (RNP) in the title. These approaches require special authorization, or "AR".

On generic RNAV approaches you may see up to three separately named minima boxes, (LNAV), (LNAV/VNAV) and (LPV). These are not just different minima for the same approach. They are in fact three separate types of approach each with their own design criteria.

LNAV is much like existing NPA's in that they have a stepdown obstacle clearance criteria. They can still be flown using VNAV, but only down to 0 degrees C, because below that the correct clearance may not be maintained. (Exception is with temperature compensating FMS systems).

LNAV/VNAV must be flown using a constant descent and VNAV because it is a sloping obstacle clearance criteria that is certified down to a temperature clearly stated on the chart. Below that temperature the LNAV/VNAV approach may not be flown, unless you have a temperature compensating FMS.

LPV approaches are also sloping, but can be flown at any temperature. That's because they require WAAS (or soon dual frequency GPS receivers) and provide vertical as well as lateral positioning guidance, unlike LNAV and LNAV/VNAV which use BARO-VNAV.

In all of these approaches the procedure must be pulled from the database and not modified in any way from the FAF to the threshold, unless you do not use VNAV then the altitude at the FAF may be modified. The waypoints, tracks, distances and altitudes must also be verified from the plate.

Overlay approaches are RNAV approaches even though the term RNAV does not appear in the title. They are flown using the FMS as the sole reference just like standalone RNAV approaches, and are therefore subject to the same restrictions and operating procedures. The aircraft must be certified, and the crew must be properly trained and certified to conduct RNAV approaches as well.

[FE Hoppy]

@ engfireleft

I would make just one correction, there are NO RNAV approaches beyond the FAF in the PBN concept. The approaches are either RNP APRCH or RNP AR APRCH.

The lowest value for RNAV is RNAV1

All of which is irrelevant to the original question, for which the correct answer is still that there are NO rnp requirements for ILS, VOR or NDB approaches.

Many people on this thread have answered the wrong question i.e. On specific equipment under specific regulations what methods of flying NPAs are certified?

For those who have chosen to answer that question I would ask, at what value EPU or ANP will your equipment alert you of error on A) an ILS b) a VOR and c) an NDB approach?

[engfireleft]

"I would make just one correction, there are NO RNAV approaches beyond the FAF in the PBN concept. The approaches are either RNP APRCH or RNP AR APRCH.

The lowest value for RNAV is RNAV1"

Thank you sir. I just re-read that portion of the PBN manual and stand corrected. Hopefully this is the final version of the naming convention.

Regarding RNAV 1, interestingly the ADS-B due for implementation in the United States beginning in 2013 and mandatory by 2020 has a navigation accuracy requirement of 0.05 nm. The bar gets raised (or lowered) yet again.

[Denti]

For those who have chosen to answer that question I would ask, at what value EPU or ANP will your equipment alert you of error on A) an ILS b) a VOR and c) an NDB approach?

a) no RNP, automatic alert is based on scale deflection, but i never talked about precision approaches anyway (APV/GLS/MLS/ILS/PAR).
b) 0.3 (no need to monitor the nav source on which this approach is build)
c) 0.3 (no need to monitor the nav source on which this approach is build).

The ICAO PBN definitions allow still for a lot of different ways to implement them and most of it is not yet fully implemented in many countries.

[aristoclis]

Suppose for some reason you don't have your 0.3. (Airbus 320 FCOM 1.22.20 p.8 says 0.3 for GPS, 0.5 for other cases)
You can still do VOR and NDB approach, can't you? Even in NAV mode with positive accuracy check and raw data monitoring (FCOM 3.03.19 p.6). As far as I know every airplane has still needles...

So what is the answer to the original question:

"what is the RNP value required for an ILS, VOR and a NDB approach? "

Answer: RNP is irrelevant. :mad:

[galaxy flyer]

Engfireleft

If I go into the database, activate a VOR/DME approach to our home drome, what kind of approach am I flying, if I arm LNAV/VNAV and fly it with FMS data displayed? I would offer that it is a VOR/DME overlay. The approach was designed to TERPS NPA standards, it is flown with a CDA to a MDA.

The approach has no specified RNP value, it was not designed to RNP or PBN standards, it is not termed RNAV or RNP, it is not charted as such. Yes, this is certified, it is trained this way, we are checked flying ground-based approaches this way.


Any thoughts?

GF

[aterpster]

FE Hoppy:

I would make just one correction, there are NO RNAV approaches beyond the FAF in the PBN concept. The approaches are either RNP APRCH or RNP AR APRCH.

I would disagree with that. :=:)

1. RNAV IAPs that are not RNP AR APRCH, are nonetheless performance based, as implied in the ICAO title you state, RNP APRCH. In other words both types of approaches you cite are performance based, except in some cases the RNP AR APRCH missed approach is not performance based.

2. All approaches that are designed to be used with LNAV or LNAV/VNAV are RNAV procedures, whether at RNP 1.0 or RNP 0.1. The degree of monitoring and alerting are a different matter.

[Stratobus]

Aristoclis, surely answer would be if approcah is flown using conventional navigation then no RNP value is required, if flown using FMS as primary source then required values are XXX.. Not simply " it is irrelevant" it is definately "relevant" from what even you say

[aristoclis]

galaxy flyer,

Are you authorized to fly this specific approach you describe without displaying any VOR/DME information in addition to the FMS data? Are you authorized to fly this approach even if the radioaid is u/s?

If you are displaying VOR/DME info for monitoring then you are flying a perfectly normal VOR/DME approach, which happens to be executed by the FMS data base and crosschecked with the radioaid and baro alt as the primary means of navigation.

Stratobus,

Well, then again interviewer should make question more specific, stating clearly that he is referring to NPAs without radioaid referrence. But again the ILS thing makes the answer to his question deffinetely: "irrelevant". Sorry.

"Not simply " it is irrelevant" it is definately "relevant" from what even you say"

I said that above 0.3 or 0.5 respectively you will have "Accuracy Low", in other airplanes the approach light on the CDU will not come on. Despite that if you have a positive accuracy (radionavaid croschecking accuracy better than 1n.m.) you can still stay in NAV and monitor radionavaid. How did you come to that conclusion that even from what I say RNP is relevant?

[FE Hoppy]

FE Hoppy:

Quote:
I would make just one correction, there are NO RNAV approaches beyond the FAF in the PBN concept. The approaches are either RNP APRCH or RNP AR APRCH.
I would disagree with that.

1. RNAV IAPs that are not RNP AR APRCH, are nonetheless performance based, as implied in the ICAO title you state, RNP APRCH. In other words both types of approaches you cite are performance based, except in some cases the RNP AR APRCH missed approach is not performance based.

2. All approaches that are designed to be used with LNAV or LNAV/VNAV are RNAV procedures, whether at RNP 1.0 or RNP 0.1. The degree of monitoring and alerting are a different matter.

No mate, you're out of date. PBN is formalised and has replaced the previous RNP standards.

http://pbnwbt.ecacnav.com/pbn_package_site/enabling_pbn/topic_pages/enabling_pbn_t03_RNAV_routes/graphics/e_t3_pg1_rgt.gif

[aterpster]

FE Hoppy:

No mate, you're out of date. PBN is formalised and has replaced the previous RNP standards.

Did I say differently? What I said was that all RNP is RNAV and all RNAV is PBN, except for some RNP AR missed approach procedures (single string only), which can miss to a VOR, NDB, or just simply fly a heading. This presumes a failure of the GPS (GNSS) system, which is a mandatory part of RNP AR procedure design.

From the current U.S. AIM:

a. General. RNP is RNAV with on-board navigation monitoring and alerting, RNP is also a statement of navigation performance necessary for operation within a defined airspace. A critical component of RNP is the ability of the aircraft navigation system to monitor its achieved navigation performance, and to identify for the pilot whether the operational requirement is, or is not being met during an operation. This on-board performance monitoring and alerting capability therefore allows a lessened reliance on air traffic control intervention (via radar monitoring, automatic dependent surveillance (ADS), multilateration, communications), and/or route separation to achieve the overall safety of the operation. RNP capability of the aircraft is a major component in determining the separation criteria to ensure that the overall containment of the operation is met.

The RNP capability of an aircraft will vary depending upon the aircraft equipment and the navigation infrastructure. For example, an aircraft may be equipped and certified for RNP 1.0, but may not be capable of RNP 1.0 operations due to limited navaid coverage.

b. RNP Operations.

1. RNP Levels. An RNP “level” or “type” is applicable to a selected airspace, route, or procedure. As defined in the Pilot/Controller Glossary, the RNP Level or Type is a value typically expressed as a distance in nautical miles from the intended centerline of a procedure, route, or path. RNP applications also account for potential errors at some multiple of RNP level (e.g., twice the RNP level).

(a) Standard RNP Levels. U.S. standard values supporting typical RNP airspace are as specified in TBL 1-2-1 below. Other RNP levels as identified by ICAO, other states and the FAA may also be used.

(b) Application of Standard RNP Levels. U.S. standard levels of RNP typically used for various routes and procedures supporting RNAV operations may be based on use of a specific navigational system or sensor such as GPS, or on multi-sensor RNAV systems having suitable performance.

(c) Depiction of Standard RNP Levels. The applicable RNP level will be depicted on affected charts and procedures.

[galaxy flyer]

Aristoclis

In FAA, display of the underlying navaid is NOT required, all done on FMS data. If display is not required, no need for the navaid to be on the air, either. It is still a VOR/DME approach flown with an overlay. The FMS must show APP, indicating the RAIM is good and scaling is appropriate. This is according to AFM, manufacturer and training establishment.

Aterpster. Any inputs on flying overlay approaches?

GF

[aterpster]

GF:

Aterpster. Any inputs on flying overlay approaches?

In the U.S. Joe Aviator can only fly them with his TSO 129 or 145/146 navigator if the chart says "VOR/NDB or GPS." Unless the IAP says that, the procedure will not be in his database as an LNAV IAP; rather an advisory IAP with no approach mode.

The high-end FMS stuff is much more varied and complex. There is overlay without it being authorized on the VOR/NDB chart. That becomes a matter of OEM, state, and aviation authority authorization.

Suffice it to say, some biz jets (which is what I work with these days) can fly a VOR or NDB IAP without "..or GPS" in the title. And, so long as the RNP value is met for LNAV overlay, that seems to me to be better than flying the raw data.

I believe others here have said most of the modern air carrier birds have the same ability, provided all the authorizations are there.

I am always learning. :)

When I flew the 767 before GPS, we used LNAV for VOR or NDB, but with the PNF monitoring raw data.

[galaxy flyer]

Aterpster

Thanks, that is my experience, Global Express and Challenger 605. We have th have APP or GPS APPR showing to pass the FAF. The Rockwell Collins system has a VGP function for APPR with VNAV, then the path acts like a glide slope with the altitude selector set for missed approach altitude.

GF

[engfireleft]

If I go into the database, activate a VOR/DME approach to our home drome, what kind of approach am I flying, if I arm LNAV/VNAV and fly it with FMS data displayed? I would offer that it is a VOR/DME overlay. The approach was designed to TERPS NPA standards, it is flown with a CDA to a MDA.

The approach has no specified RNP value, it was not designed to RNP or PBN standards, it is not termed RNAV or RNP, it is not charted as such. Yes, this is certified, it is trained this way, we are checked flying ground-based approaches this way.


Any thoughts?

It doesn't matter which type of approach you activate in your FMS, what matters is what you are using as a primary reference. If you are flying an NDB or VOR approach then you must have the radio tuned and displayed as your primary reference. It then doesn't matter what is in your FMS, in fact your FMS could blow up in your face and you are still able to fly the approach.

If you are using the FMS as your sole reference it doesn't matter what the approach is called in the box. It could be called the moon7 approach, but if you are using the FMS as the primary reference then you must comply with the same procedures as an RNAV approach. Why? because you are using the FMS as a reference.

Why do you think they have all those procedural and certification requirements for RNAV approaches, but wouldn't have them for an overlay when you are using the same reference?

You either fly a VOR approach, or you fly an overlay approach. They use the same profile, they use the same approach plate, but the biggest difference you seem to be missing is that they use entirely different references. Using the VOR has its requirements, and using FMS has different requirements that are the same for standalone RNAV approaches.

[galaxy flyer]

engfireleft

If you are flying an NDB or VOR approach then you must have the radio tuned and displayed as your primary reference.

As I said, that is NOT true. One, with FAA approval, can do so with the proper equipment. There is no requirement on a Global or Challenger (ProLine 4 or 21) to tune, display or monitor the underlaying navaid. Obviously, you must have and use a current database, have the crew training, and have the correct annunciations. There is no RNP associated with the underlying approach, so no need for a specified RNP. We just need to have APPR annunciation, indicating proper RAIM calculations and, at least, 1 nm scaling.

With 2,000 hours in these types, I understand what navigation sources are being used or not. It is a matter of regulatory approval. Here is the relevant part of AC 90-94

Phase III. Phase III began April 28, 1994, when the first instrument approach procedures were published to include “or GPS” in the title of the published approach procedure. Neither the aircraft traditional avionics nor the underlying ground station navaid(s) need be installed, operational, or monitored to fly the nonprecision approaches at the destination airport. For GPS systems that do not use RAIM for integrity, the ground-based navaid(s) and the airborne avionics that provide the equivalent integrity must be installed and operating during the approach. For any required alternate airport, the traditional ground-based and airborne navigational equipment that defines the instrument approach procedure and route to the alternate must be installed and operational.

It is OBE, but does apply for systems approved under it.


GF

[changer]

this conversation is getting interesting!http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/thumbs.gif

I beg to differ, newer boeings do it all with the APProach button.I'm curious which Boeings you're referring to. I'm on the 777 now, and have flown the 757/767 previously. The approaches are flown in these airplanes just as I described (below)

...Boeing airplanes have two different buttons to hit to commence the approach, and which button you hit depends on what kind of approach you're doing. If you're doing an ILS approach (autoland or not) you hit the APProach switch. That connects the autopilot and/or Flight Director to the LOC and GS. If you're doing a RNAV approach, you hit the LNAV button, which does NOT connect the AP/FD to the LOC/GS

[9.G]

galaxy flyer, true or not true depends entirely on OPS specs of the operator and state approval e.g. AIP. FAA does allow the nav aid to be u/s EU OPS doesn't, as simple as that. :ok:

[Denti]

@changer, the 737NG and 787 can do it all using the APProach mode, older 737 still have to use LNAV/VNAV, and of course if you are equipped to fly other than ILS precision approaches, for example GLS (standard for the last 5 years on our 737s) or MLS, there is no LOC/GS to connect to in the first place. It's called IAN and provides a FMC generated localiser and glide slope alike presentation for NPA approaches.

galaxy flyer, true or not true depends entirely on OPS specs of the operator and state approval e.g. AIP. FAA does allow the nav aid to be u/s EU OPS doesn't, as simple as that.

True, however EU OPS does not require that it is displayed and monitored. Might be a special approval since we used that allready back when JAR-OPS was current and it is now grandfathered in, but i seriously doubt that.

[9.G]

Denti, let's keep it simple as usual. Whatever is written on the plate shall determine the type of approach one will fly, hope we all agree so far.
Unless you fly a GPS (DME/DME if approved) raw data monitoring is required due to following:
1.8 APPROACH OPERATIONS UTILIZING BARO-VNAV EQUIPMENT

1.8.1 Baro-VNAV equipment can be applied to two different approach and landing operations:

a.
Approach and landing operations with the vertical guidance. In this case, the use of a VNAV system such as baro-VNAV is required. When baro-VNAV is used, the lateral navigation guidance is based on the RNP APCH and RNP AR APCH navigation specifications.

b.
Non-precision approach and landing operations. In this case, the use of a baro-VNAV system is not required but auxiliary to facilitate the CDFA technique as described in 1.7.2. This means that advisory VNAV guidance is being overlaid on a non-precision approach. The lateral navigation guidance is predicated on the navigation system designated on the chart.

Furthermore Airbus FM says following:

Approach Procedure with GPS PRIMARY

Before starting the approach, check that GPS PRIMARY is available on both MCDU.
If GPS PRIMARY LOST indication appears on ND during the approach, discontinue the approach unless :
‐ GPS is not required and navigation accuracy is confirmed against the radio navaid raw data, or
‐ For RNAV approach not requiring GPS, HIGH accuracy is displayed on MCDU with the appropriate RNP value.
‐ If GPS PRIMARY is lost on only one FMGC, the approach can be continued using AP/FD associated to the other FMGC.

Once again all depends on which approach you're shooting. :ok:

[9.G]

the reference made earlier to the US specs was referring to the GPS approaches as well

GPS Approach Procedures

As the production of stand-alone GPS approaches has progressed, many of the original overlay approaches have been replaced with stand-alone procedures specifically designed for use by GPS systems. The title of the remaining GPS overlay procedures has been revised on the approach chart to “or GPS” (e.g., “VOR or GPS RWY 24,” “GPS RWY 24,” or “RNAV (GPS) RWY 24”). During these GPS approaches, underlying ground-based NAVAIDs are not required to be operational and associated aircraft avionics need not be installed, operational, turned on or monitored (monitoring of the underlying approach is suggested when equipment is available and functional). Existing overlay approaches may be requested using the GPS title, such as “GPS RWY 24” for the VOR or GPS RWY 24.

NOTE: Any required alternate airport must have an approved instrument approach procedure other than GPS that is anticipated to be operational and available at the estimated time of arrival and which the aircraft is equipped to fly.

Once again it's the title in the right corner determining the primary means of navigation. OR GPS means can be flown as GPS stand alone approach :ok:

[Denti]

And apparently it depends on aircraft type. I posted above the relevant excerpt from a EU-OPS approved 737 FCOM which states quite clearly "raw data monitoring is not required".

Of course the approach is predicated on the relevant nav aid, but that doesn't necessarily mean you have to check it if there are other means of compliance which assure you stay within the limits of the relevant approach.

In terms of RNP monitoring boeing makes it very easy, it directly displays your ANP and RNP as navigation performance scales on the PFD and on the legs page on the CDU. No need to care about GPS or RAIM, as long as your ANP is within limits everything is fine.

[aristoclis]

Galaxy Flyer,



Phase III. Phase III began April 28, 1994, when the first instrument approach procedures were published to include “or GPS” in the title of the published approach procedure. Neither the aircraft traditional avionics nor the underlying ground station navaid(s) need be installed, operational, or monitored to fly the nonprecision approaches at the destination airport. For GPS systems that do not use RAIM for integrity, the ground-based navaid(s) and the airborne avionics that provide the equivalent integrity must be installed and operating during the approach. For any required alternate airport, the traditional ground-based and airborne navigational equipment that defines the instrument approach procedure and route to the alternate must be installed and operational.

This statement in bold is true as long as you have the "or GPS" on the plate.

AIM 1-32 paragraph 3 (2004)
The GPS Approach overlay Program is an authorization for pilots to use GPS avionics under IFR for flying designated nonprecision instrument approach procedures, except LOC, LDA and simplified directional facility (SDF) procedures. These procedures are now identified by the name of the procedure and “or GPS” (eg., VOR/DME or GPS RWY 15). Other previous types of overlays have either been converted to this format or replaced with stand-alone procedures. Only approaches contained in the current onboard navigation database are authorized. The navigation database may contain information about nonoverlay approach procedures that is intended to be used to enhance position orientation, generally by providing a map, while flying these approaches using conventional NAVAIDS. This approach information should not be confused with GPS overlay approach (see the receiver operating manual, AFM, or AFM supplement for details on how to identify these approaches in the navigation database.

Glad to here if something has changed in the US since then.

I am sure your airplanes are capable of doing many many things, but this is not the issue here.

Again I would be very glad to know which eu countries permit to fly a conventional VOR/DME approach when the radionavaid is unserviceable...

[9.G]

excerpt from 777 FCTM:
Raw Data Monitoring Requirements
During localizer-based approaches; LOC, LOC-BC, LDA, SDF, and IGS, applicable raw data must be monitored throughout the approach.
During non-localizer based approaches where the FMC is used for course or path tracking (VOR, TACAN, NDB, RNAV, GPS etc.), monitoring raw data is recommended, if available. Although continuous monitoring of raw data during approaches is not required, ground based navigation aid(s) should be checked for correct navigation no later than final approach.

Airbus:
VOR, VOR/DME, NDB or NDB/DME approach procedures may be performed, in NAV, or NAV and FINAL APP mode, provided AP or FD is used, and : GPS PRIMARY is available.
In this case, the reference navaid may be unserviceable, or the airborne radio equipment may be inoperative, or not installed, provided operational approval is obtained.

Without GPS PRIMARY :
The reference navaid and the corresponding airborne equipment is serviceable, tuned, and monitored during the approach, or the radio navaid coverage supports the RNP value, specified for the approach procedure, and an operational approval is obtained.

For GPS approach, GPS PRIMARY must be available.

Once again, I strongly suggest to check your part A for the operator's approval as a manufacturer recommendation doesn't imply operational approval.:ok:

Aristoclis, no matter EU OPS or AIM unless you fly a GPS approach or one of those OR GPS approaches monitoring of a raw data is required as it constitutes primary navigation means. :ok:

[FE Hoppy]

@aterpster

it was your quote:
1. RNAV IAPs that are not RNP AR APRCH, are nonetheless performance based, as implied in the ICAO title you state

that I'm not convinced by.

In the ICAO title I stated there are no approaches named "RNAV". All approaches are RNP.

That's not to say that RNP isn't a type of "area navigation" specification which uses performance as the basis for procedural design.

Semantics I know, but as a simpleton I need as much clarity as I can get. I certainly didn’t mean to cause offence.

[ImbracableCrunk]

the 737NG and 787 can do it all using the APProach mode, older 737 still have to use LNAV/VNAV, and of course if you are equipped to fly other than ILS precision approaches, for example GLS (standard for the last 5 years on our 737s) or MLS, there is no LOC/GS to connect to in the first place. It's called IAN and provides a FMC generated localiser and glide slope alike presentation for NPA approaches.

Whoa. You do LNAV approaches with APP mode in the 737NG?

From my current FCOM:

The approach mode arms AFDS to capture and track localizer and glideslope and can be engaged for dual or single autopilot operation.

One VHF NAV receiver must be tuned to an ILS frequency before approach mode can be engaged. With one VHF NAV receiver tuned, onside AFDS is enabled for guidance and operation.

Do you have a reference?

[engfireleft]

engfireleft


Quote:
If you are flying an NDB or VOR approach then you must have the radio tuned and displayed as your primary reference.
As I said, that is NOT true. One, with FAA approval, can do so with the proper equipment. There is no requirement on a Global or Challenger (ProLine 4 or 21) to tune, display or monitor the underlaying navaid. Obviously, you must have and use a current database, have the crew training, and have the correct annunciations. There is no RNP associated with the underlying approach, so no need for a specified RNP. We just need to have APPR annunciation, indicating proper RAIM calculations and, at least, 1 nm scaling.

With 2,000 hours in these types, I understand what navigation sources are being used or not. It is a matter of regulatory approval. Here is the relevant part of AC 90-94


Quote:
Phase III. Phase III began April 28, 1994, when the first instrument approach procedures were published to include “or GPS” in the title of the published approach procedure. Neither the aircraft traditional avionics nor the underlying ground station navaid(s) need be installed, operational, or monitored to fly the nonprecision approaches at the destination airport. For GPS systems that do not use RAIM for integrity, the ground-based navaid(s) and the airborne avionics that provide the equivalent integrity must be installed and operating during the approach. For any required alternate airport, the traditional ground-based and airborne navigational equipment that defines the instrument approach procedure and route to the alternate must be installed and operational.
It is OBE, but does apply for systems approved under it.


GF


If you don't have the VOR tuned you are not flying a VOR approach. If you don't have the ILS tuned you are not flying an ILS approach. If you are flying an approach using the FMS as primary guidance you are flying an RNAV approach. Your quote from the AC even says so (read the bolded sentence, if you did it back then you are flying a GPS approach, not VOR). If for instance the title of the approach was "VOR RWY 25" you could not do the approach if the VOR was not functioning. Why not? Because it didn't say "or GPS" in the title.

But even that is out of date because they are not called GPS approaches anymore although some plates may still have that in the title. According to the ICAO PBN manual they aren't even called RNAV approaches anymore, but almost all of the plates still say RNAV (in Canada overlays have (GNSS) in the title). It takes a while for naming nomenclature to make its way through the system.

Another thing I'm detecting here is too much reliance on aircraft FCOM's and FCTM's to tell the crew what they can and cannot do. If the aircraft says it will do something that doesn't mean you can from a regulatory standpoint, and vice versa. If the aircraft FMS displays a specific RNP during certain phases of flight, that doesn't mean that's the RNP that is actually required. You will notice that virtually all aircraft have the ability to input different RNP values by the crew.

One example of what I mean is GPS equipped Airbus. The RNP will automatically decrement down to 0.3 nm, but only if the approach selected from the database is titled "GPS". It won't if the approach is titled "RNAV" even though you still need 0.3. So the pilot has to select it manually.

PBN is a rapidly evolving discipline and it is impossible for a single country to keep everything up to date which is why you still have "GPS" approaches around even though they aren't officially called that anymore. When you bring different countries into the mix it is a hundred times worse than herding cats.

[Denti]

Do you have a reference?

Of course:

Airplanes with IAN are capable of using the MCP APP switch to execute instrument approaches based on flight path guidance from the navigation radios, the FMC, or a combination of both. All IAN approaches provide the functions, indications and alerting features similar to an ILS approach. Although non-ILS approaches using LNAV and VNAV can still be performed, IAN is normally used in place of LNAV and VNAV because of improved approach displays, alerts and standardized procedures.

IAN approach types:
• RNAV
• GPS
• VOR approach
• NDB approach
• LOC, LOC-BC, LDA or similar approaches.

Note: IAN annunciations are not displayed on the standby ADI or ISFD.

For LOC based approaches the localizer has to be tuned, however if the localizer is identical to an ILS you have to select G/S off on the INIT REF page or when selecting the approach. For all other approaches you have to make sure not to tune any ILS/LOC frequency, but there is no required nav aid setting (company recommends to tune the relevant nav aid, but again, it is not required).

IAN is limited to single channel autopilot usage and CAT I minima (there will be an auto-callout "AUTOPILOT" at 100ft AGL to remind the pilots to disconnect the AP), however the APProach mode works for GLS as well which is capable of autoland and automatic rollout to CAT IIIb minima (although only certified for CAT I currently) both for both engines and CAT IIIa with automatic rollout for OEI same as ILS, but different to ILS curved approaches and approaches with different descent angles during different parts of the approaches are possible.

[9.G]

to finalize the subject here is the reference from FLIGHT PROCEDURES (DOC 8168) - GENERAL PRINCIPLES Extracted from ICAO Document 8168, Volume I - Fifth Edition — Flight Procedures, PROCEDURES FOR AIR NAVIGATION SERVICES — AIRCRAFT OPERATIONS, herein known as PANS-OPS.

USE OF FLIGHT MANAGEMENT SYSTEM (FMS)/AREA NAVIGATION (RNAV) EQUIPMENT Where FMS/RNAV equipment is available, it may be used to fly conventional procedures provided:
a. the procedure is monitored using the basic display normally associated with that procedure; and
b. the tolerances for flight using raw data on the basic display are complied with. The conclusive answer is obvious. :ok:

[Topper80]

so make me clear:

VOR, VOR/DME, NDB or NDB/DME approach procedures may be performed with the FMS stored procedures, but the reference navaid must be serviceable and the airborne radio equipment must be operative and monitored... And ANP at the same time... :ugh:

[FlightDetent]

No?. 9.g provides the full verse. You may adopt LNAV or so for conventional APCHs, as long as you monitor raw data navaid and stay within its limits.

No regulatory ANP value. Not needed.