I’m not saying this is sensible.
But I find the ADF the most useful Nav aid in aircraft that I fly and I find it far more useful than the VOR. I basically fly two/four seat training aircraft usually at lowish levels and frequently IMC outside of controlled airspace. These aircraft tend to have minimal equipment and very few have an approved GPS or if they did the database is out of date.
Most if not all airports that have commercial traffic have an NDB with a range of something like 25 nm and used in conjunction with touchdown DME this tends to give you a half decent position fix.
You can also tune in to commercial radio stations and using these you frequently get ranges of 100nm and these are excellent for long range navigation.
As for VOR well they are not really located anywhere useful anymore. Newcastle VOR has gone for instance (but the NDB is still there). Also the number is being reduced and at low levels you can’t always tune one in let alone two.
Another plus for the ADF is I can practice ADF approaches and holds for free using a local radio stations plus you don’t have the hassle of not being able to “book the beacon” and some spaceport than has two flybe movements a day.
These aircraft tend to have minimal equipment and very few have an approved GPS or if they did the database is out of date.
In a practical sense, it does not make sense to maintain an ADF and DME (in a very basic plane) and not have a decent GPS in there. Such an existing configuration must be maintained for a specific reason, and it is not one connected with flying from A to B…
I really don’t want to be over-assuming something but it is well known that the UK IR/ATPL training business deliberately flies with an out of date GPS database, to make sure that the GPS cannot be used in the test. Then, they don’t need to teach it. I have this from a source who is extremely familiar with the UK scene.
You can also tune in to commercial radio stations and using these you frequently get ranges of 100nm and these are excellent for long range navigation.
If you know where the transmitter is, which a lot of the time is not known, short of intimate local knowledge.
Another plus for the ADF is I can practice ADF approaches and holds for free using a local radio stations plus you don’t have the hassle of not being able to “book the beacon” and some spaceport than has two flybe movements a day.
That’s true… but this is an issue only because NDB holds are still in the syllabus. It is a self perpetuating system. They have to be in the syllabus because the IR is supposed to enable the holder to fly anywhere IFR, and there are loads of airports with NDB holds.
The activity around airspace, OPS and FCL these years is all about the transition into Performance Based Navigation, which is GNSS (increasingly with SBAS/EGNOS/WAAS), with ILS’s available at larger airport for some more years, and DME to back it all up. VOR’s and Locators/NDB’s are simply not there in the future navigation system. Even ILS’s have started being decommissioned in France, to be replaced by the much cheaper (for the airport) LPV and LNAV/VNAV approaches. And those GPSS approaches are popping up at smaller airports at a high rate all over Europe.
From 2018 any newly rated IFR pilot will have to be PBN/RNAV/GPSS trained and tested, and from 2020 it will no longer be possible to have an IFR rating without having been trained for the PBN/GPSS. Keeping up the NDB/ADF system by then will simply not make sense.
UK being UK may continue with conventional navigation for a little longer against everything EASA and Eurocontrol says, but IFR is an international thing. I have already said that I enjoy playing the ADF very much, but to go back to the original question: installing an ADF today would simply be a poor investment.
Peter wrote:
If you know where the transmitter is, which a lot of the time is not known, short of intimate local knowledge.
The Australian AIP includes frequencies and Lat/long of AM transmitters and the are marked on the WAC charts….very useful for listening to the cricket…
It does not require a lot of research to find the coordinates of MW stations in Western Europe, either. A/M becoming more and more a HAM thing, a lot of information is available in HAM environments, websites not excluded.
One could consider setting up a table of them on the www, for the benefit of those last Mohicans carrying an ADF around, but I see little practical use to it, in these days of GPS.
As a backup to GPS – one never knows when it becomes unavailable! – I understand DME is the generally preferred alternative.
Your GPS receiver is orders of magnitude more likely to fail than the space segment, so a backup for GPS is a second GPS, preferably with primary (non rechargeable) cells. Same goes for an electrical failure in your plane which is also orders of magnitude more likely to happen than the GPS network going down and staying down.
DME is not easy to use for navigation because it generally picks up only the DMEs in enroute VORs. The range of terminal DMEs is a lot less. And it just gives you triangulation, so you have to plot your position circles and see where they intersect…
At a Eurocontrol conference a few years ago it was made very clear that ATC regards itself i.e. radar control as the backup for navigation. So you need to make sure you have a spare radio…
I know NDBs of decades ago, with powers in six figures, provided great navigation facilities. And over water, or fairly uniform terrain, and with classy aircraft equipment, they can be accurate in bearing to better than 1 degree (as good as a VOR on a good day). This was proven many times, as any old RAF hand will tell you. And the ADF in my plane has repeatedly shows itself to be that good (a degree or two, for an NDB waypoint straight head, in the middle of “featureless” N France). But that is not the typical GA flight scenario.
I would not install an ADF in a homebuilt, though I am saying this having already collected all the papers I want (IR, etc). If I didn’t have the IR and wanted one, I would check out the non-ADF checkride options.
There are bound to be options around the place. For example in 2011 I looked at Egnatia at LGKV for the 15hr FAA IR to JAA IR conversion (they do initial IR too). They do VOR approaches at Kavala LGKV and then pop down the road to Thessaloniki LGTS for an ILS. That covered the NP and P approach as specified in the syllabus. NDBs were taught in the ground school….. I didn’t go there for mostly unrelated reasons. Another option was an outfit called FIS at Jerez, Spain, which was run from IIRC Austria and was doing the same deal (VOR at the sleepy Granada, ILS at Malaga, and NDBs taught on the ground only). This kept the conversion to 5 days (the min time was 15hrs so, hey ho, a good setup 
)! At least 2 people on here did their IR conversion at FIS, both in 5 days – until their main FI took a swim at the end of a ferry flight, very near Hawaii (the rescue is on youtube). Later, FIS became “gold plated NDB”-UK-run and joined the other Jerez outfit, FTE, as another FTO whose airline pilot students waste their life banging holds around the local NDB while sweating like pigs in their ex-Transair nylon uniforms…
As I said before, with a homebuilt you can literally pick up a 100% working KR87 off US Ebay, should you need one. No paperwork needed. In fact I have a complete system as a spare on the shelf, with 8130-3 forms, but I need it. I got it for about $2k.
I should have looked at this before – CAP773 – Flying RNAV (GNSS) Non-Precision Approaches in Private and General Aviation Aircraft
4.15 Missed approach procedures
GNSS systems are more susceptible to interference and jamming than the terrestrial
approach aids. Before commencing an RNAV (GNSS) missed approach, a MAP should
be possible without reference to GPS derived navigation so that, in the event of a loss of
GPS accuracy or loss of integrity during the approach, a safe return to above Minimum
Sector Altitude can be made. This may be possible by dead reckoning (DR) navigation
but where this is not possible and the MAP requires reference to terrestrial navigation aids,
these must be available, tuned and correctly identified before passing the IAF and remain
available throughout the approach.
(my underline)
In other words, if you can return to the MSA by dead reckoning, you don’t need to use the ground-based nav aids for the MAP. At Cambridge and Cranfield, there are no obstacles or terrain that you can’t out climb from the MAPt if you just maintain the approach heading (or any heading for that matter).
I’ve not heard of this before. Is it sufficient to make it legal? Would it count for an IR revalidation? Or, is it trumped by something else?
Raiz wrote:
In other words, if you can return to the MSA by dead reckoning, you don’t need to use the ground-based nav aids for the MAP. At Cambridge and Cranfield, there are no obstacles or terrain that you can’t out climb from the MAPt if you just maintain the approach heading (or any heading for that matter).
I’ve not heard of this before. Is it sufficient to make it legal? Would it count for an IR revalidation? Or, is it trumped by something else?
I don’t read that as an option for the pilot, but rather for the procedure designer….
AnthonyQ wrote:
I don’t read that as an option for the pilot, but rather for the procedure designer…
The document is called “Pilots’ guide to flying RNAV (GNSS) approaches in general aviation aircraft” after all, and it clearly talks about what the pilot should do. So I don’t read it that way. Also reinforced by the quote: “where this is not possible and the MAP requires reference to terrestrial navigation aids, these must be available, tuned and correctly identified before passing the IAF”. Tuning navaids is clearly something that a pilot does, not a procedure designer.
But it might be common sense and wishful thinking by the person who wrote this, without foundation in the regulations…?
Edit: Or, more likely, imprecise language and not what was really intended to say.
CAP773 is one of great many UK CAA documents which have a lot of good stuff in them interspersed with a lot of personal opinion, but there is no way to tell which bits are the regs and which bits are the opinion.
e.g.
At one level one might say: No s**t Sherlock
BUT… “in accordance with the operator’s SOP”? On a privately operated aircraft? What the hell is this about?
Has there ever been a concession in Europe enabling an IAP to be flown in any manner other than as charted?
