Look at LKKU – there is NDB app 21C using two NDBs. Can´t be substituted by GPS strictly legally speaking. no comment on this.
Don’t know how it is in the UK, but here in NL you’re supposed to fly an approach or holding with the procedure loaded on the GPS.
I did a VOR/DME approach during the profcheck earlier this year, keeping the GPS OBS in the middle. VOR OBS was 1/4 scale off all the way to the RWY. No one complained.
you are completely right: In Russia there used to be practically no VORs as these would be pretty useless for the distances there, that´s why NDBs were the norm. So for “precision” approaches there were two NDBs for each approach area and a marker antenna in the aircraft sending audio signals to the headsets when overflying the outer marker ca. 5km distance and so on. The ADF had two frequencies to dial directly to switch between them for approaches.This system worked quite effectively for decades, I guess – with Russian avionics, that is, no US crap.
I say NDBs will be around for quite some time being very cheap to run but VORs will be torn down for cost cutting reasons rather sooner than later while most nav duties relying on GPS systems. I have seen VORs disappear but no NDBs yet.
I have seen VORs disappear but no NDBs yet.
In Switzerland, all but one NDB (rumour says on the request of flight instructors) have disappeared.
Switzerland is different though. I think they take advantage of not being in the EU so they can ignore EASA regs as they wish, which is probably what enabled a Swiss pilot I personally know to do his initial IR test using the GPS instead of the ADF. The examiner said to him “why use the ADF when the GPS is so much more accurate and it’s what everybody uses to fly NDB approaches”.
The Russian dual-NDB system is interesting, as I believe it eliminates the worst errors. If you have the two needles pointing on opposing bearings then you “must” be lined up with the runway. Not sure, however… since individually they can still both point to the nearest TS.
NDB’s are slowly disappearing from Belgium, too. WW near Antwerpen was deactivated a couple of years ago, for example. I suppose that, even when the actual transmitters are gone, the names will remain in the navigation databases as mere waypoints, so many pilots are so used to them for enroute navigation. MAK is a good example, I think nobody flies into Kortrijk without referencing it.
But, where we sometimes hear the trend is towards DME/DME as an alternate for GPS, I hear of no DME stations being added. We already have quite a few on our little territory, though.
I think they take advantage of not being in the EU so they can ignore EASA regs as they wish
I wish it was like that, but this couldn’t be farther from the truth. FOCA tends to start to implement EASA rules when they’re at the commenting stage.
I suppose that the names will remain in the navigation databases
Not normally. When TGO (Tango) was decommissioned, they put an intersection named TEDGO at its location. EUR (Eurach) doesn’t seem to have an intersection, NINUR is close but not exactly where Eurach was
I think they take advantage of not being in the EU so they can ignore EASA regs as they wish, which is probably what enabled a Swiss pilot I personally know to do his initial IR test using the GPS instead of the ADF. The examiner said to him “why use the ADF when the GPS is so much more accurate and it’s what everybody uses to fly NDB approaches”.
That is what my German examiner told me as well. When I was trying to tune the ADF he said “what you doing? You have GNS430, don’t mess with this useless ADF, use the best tools you have”.
Everybody substitutes in reality but the regulations are a bit behind on that. Can’t remember when I last used the ADF.
But, where we sometimes hear the trend is towards DME/DME as an alternate for GPS, I hear of no DME stations being added. We already have quite a few on our little territory, though.
It was mentioned at a Eurocontrol “nav workshop” a few years ago that another 500 DMEs were to be installed in Europe, to support DME/DME navigation.
The “slight problem” is that there isn’t a GA product which does that, and is never likely to be. GPS caused the bottom to fall out of the nav market many years ago and it will never recover.
One could build one easily enough, because any modern DME is remotely tuneable so all you need is a starting position (use a GPS for that) and a database of the DMEs, and if you get an initial direction vector then you are all set to go. No way to make it certifiable, but who cares? It would just be a switch, selecting whether your DME gets its frequency selection from the NAV radio(s), or from your gadget, and a connector in the panel. The whole thing could run on a little processor board, which would output NMEA, radiated over bluetooth to emulate a standard NMEA (non-Apple preferably) bluetooth GPS! Anybody fancies building such a thing?
As you said Peter, that would make an interesting project for someone who enjoys tinkering with microcontrollers. I reckon the gimmick would have to read data from the DME receivers over ARINC, just like it would use ARINC to set them to the required frequency?
But, also as you said, there can be little if any interest for it if it is uncertified. Certified as a backup location detector it could perhaps have some value, but I doubt if the cost of certification could ever be recovered – a device of this kind will not sell by the thousands anyway.
BTW I think the need for a GPS for initial location could be eliminated, aiding a bit in simplifying the thing and perhaps a bit more in getting it certified. And to offer any added value, GPS-independency is a first requirement.
