There seems to be a bit of doubt as to how the top of the line aircraft fly NP approches and company rules and the views of some regulators differ somewhat ( so much for one set of rules under EASA ) but these are the basic rules I have flown under four EASA regulators.
I am assuming that a multi sensor FMS is fitted ( GPS, VOR, ILS, DME, IRS ).
If you need to fly an NDB approach you check that the waypoints in the database are the same as on the chart.
You then select the NDB and bring it up on the NAV display and identify it ( without this you can’t fly the approach as it is the primary aid ).
You then fly the approach using LNAV / VNAV fully coupled to the autopilot but monitoring the ADF indication.
In the event of an ADF VNAV disagree ADF info is your primary source of info, ( but I would go around and find out why the disagree happened )
Dependent on type if you go around the autopilot may disengage when you hit the TOGA button but can be re-engaged once the go around is underway.
NOTE………… You are not allowed to load any pilot generated waypoints for the approach, the approach waypoints MUST all be in the FMC data base.
I spoke to one AOC operator in Italy and his approved procedure was
Another operator, UK IIRC, had
In both cases they would ask for the “NDB” IAP, so that’s what you hear on the radio, but they would fly it using FMS guidance, with a “glideslope”, all the way to the NDB IAP minima.
AFAIK none of these systems allow a totally DIY IAP. There has to be some sort of IAP published; that is yet another reason why NDBs remain popular: you have to publish an IAP, so you have to have the actual navaid at the airport, and an NDB is the cheapest way to do it.
AFAIK GPS approach capability costs too much money for many regional ops – into 6 figures. And if there IAP already exists and the GPS/LNAV procedure gives no better minima, why bother?
It’s like asking me why I don’t spend 30k+ on installing LPV capability (2×IFD540; could do it for a lot less but it would be a bodge). From the UK, I have to fly to a customs/immigration airport, and thus far I have not come across a single such airport which had LPV and didn’t have ILS, or didn’t have ILS but had a conventional IAP and the wx was not well above the IAP minima and there was no ILS alternate (e.g. an ILS on Mali Losinj would be somewhat wasted, when Pula has an ILS) 
I am throwing all this into the pot to illustrate why LPV is slow coming in the UK and elsewhere. Nobody will do anything for GA. All the services we use are for commercial traffic and some (FIS) are ICAO obligations. Ask any NATS person and they will tell you pretty directly this is because “you” are under 2000kg. An airport won’t install LPV unless they can see enough extra traffic, and currently almost no GA has LPV, even less CAT has LPV, and most people won’t install the aircraft kit unless there is a tangible benefit (via a reduced MDA) especially if they already have GPS/LNAV+V which “works” all the way to the tarmac 
Shoreham EGKA is a good example where you have +V already, albeit with a “useless” DH of 800ft. But in pure safety terms an LPV with a DH of say 500ft won’t give you something you don’t already have flying the +V with an “imagined” DH of 500ft. Well, that LPV DH would be driven by the go-around performance requirement and that is, ahem, something else…
Cobalt wrote:
But I am not the one trying to force others to spend money (thousands) on buying and maintaining obsolete navigation equipment.
I don’t try force otehr spend a lot of equipment on obsolete equipment. On upgrades, if there is panel space, and the equipment is working, I will always recommend to leave it installed.
Like A_and_C I think most people seem to think of GPS as a system which can not fail. That is not true, and the problem is likely with their own aircraft. One would have to be aware of this issues, and think about this. Then decide on what kind of equipment you want or want to get rid off.
Especially with removal of DME. Using GPS as DME has shown to be deadly on more then one crash.
Wether you like it or not, modern avionics are much less reliable then older avionics, when they were new.
I agree with the need for a DME when flying ILS/DME approaches, since trying to substitute is fraught with likely operational errors, and have argued the case for having it myself. Nothing to do with likely failure of equipment, though.
I object to the general “you need a mandatory backup for GPS because it might fail.”, having LPV approaches with ADF as required go-around aid introduces such a mandate.
Timothy wrote:
The argument for DME is not to do with loss of GPS, but in the common errors in interpreting it as a fix substitution aid. That was the fatality I pointed to.
But this results from the fact that DME, in spite of its name, does not display distance from the station at all time, but in many cases something else. This comes from a time when it was not easy to simply define an arbitrary sequence of points as an approach. With GPS (or multi-sensor FMS) it is now possible, therefore IAP designs should utilise this capability completely. And the discrepancy between the DME value and the GPS distance is more like an argument for removing references to DMEs in IAPs, not for the carriage of DME…
Jesse wrote:
I do not know what was the cause on the photo from Timothy, but it clearly shows that GPS can fail inflight. Having a second GPS is not always the answer. From that point of view I think A_and_C has valid arguments.
I don’t agree with the proposition that if you fly the approach with a functioning WAAS GPS to LPV minimums that there is any substantial risk flying the remainder of the procedure using GPS. If a GPS fails in flight, sure it can’t be used, but you won’t be flying the approach in the first place.
Neil wrote:
Are there any approaches in the USA that use NDBs in the MAP? I have not flown extensively in the USA except in sims, but all the GPS approaches I have come across use GPS for the missed.
No. Not in the over 14000+ RNAV approach procedures in the US. If the approach is RNAV, then an appropriate GPS is all that is required to fly the procedure.
Timothy wrote:
Let us remember that the bulk of overlays in USA are approved as RNAV approaches.
There are very few overlays remaining in the US. Those that do exist are titled with “or GPS” and are not RNAV procedures. The overlay program was instituted when there were almost zero GPS stand alone procedures. When RNAV procedures were published, the overlays were eliminated, so now, most VOR or NDB based approaches in the US do not have a GPS option and pilots may not fly these procedures without the VOR/ADF being in service, the equipment installed, and the CDI/RMI displaying the course. You can use GPS, but the ground based Navaid CDI/RMI is primary for course guidance.
RobertL18C wrote:
AandC this applies to airways? In the approach environment the line of sight for DME/DME might not be available, especially with planned de commissioning of VOR/DME and VORTAC stations.
In the US, VOR’s are being decommissioned, but not DME. When a VOR-DME or VORTAC is decommissioned, the DME remains to be available to support DME-DME RNAV. In fact some places, DME’s are being added.
I have been speaking with a Proline 21 bizjet pilot.
It sounds like what it does is:
It appears that +V is never flown, and may be unsupported by Proline.
