ADF and European navigation (merged)

It would depend on what I wanted to do with the aeroplane, where I wanted to fly. I agree with others, DME is more valuable to me. But if I could get used units in good condition and install them without significant expenses (I’m talking mainly about paperwork, I don’t know the requirements in your case), I would probably take both. And I would be looking into installing them remotely.

Jan_Olieslagers wrote:

Talking of that, did I understand the Russians had at one time a kind of standard (more or less) precision approach, basing upon two NDB’s, located a bit like an ILS’s outer and middle markers?

I think dual-NDB approaches are still there a perhaps elsewhere in the eastern part of Europe. AFAIK there are several variants. I think you can also find them in South America. I vaguely recall two ADFs being required down there somewhere.

Peter wrote:

I don’t know the current situation but it seems obvious to me that with there being no GPS substitution concession in Europe, there cannot be a way to avoid the issue other than to find the right sort of approach.

I remember reading a warning fairly recently that if your aircraft doesn’t have the needed equipment (for the approaches that are available more locally), the test might take longer than usual (as you’ll have to fly somewhere suitable).

I remember reading a warning fairly recently that if your aircraft doesn’t have the needed equipment (for the approaches that are available more locally), the test might take longer than usual (as you’ll have to fly somewhere suitable).

Very much so.

Or, it rules out NDB approaches altogether. In the UK, the CAA examiner always had that option (I got a VOR+ILS) but you could not ask for it. And there are definitely VOR/DME approaches, which any half reasonable IFR plane can fly.

Locators/NDB’s are going away fast worldwide, so no. The last time I used an ADF for navigation other than training/test was in 2001 when I was directed towards an en-route NDB holding in Southern Norway. The equipment is heavy, expensive, draws a lot of current and is not very reliable. Remember, there is no warning or flag if the needle suddenly becomes unsafe to navigate by – which is why some sadistic instructors insist that the ADF should ident loudly through the audio during the whole approach.

But I am going to miss the old boxes for a number of reasons:

• You can use it to adjust the DI / check the compass even when airborne because the ADF is the only nav.instr. whose indication relates to the orientation of the aircraft
• You can tune strange radio stations from far away (or can you still? I haven’t done that for many years now)
• You can use the outer ring of the needle clock to set the cleared altitude (I do that as a matter of routine when IFR)
• You can use erratic movements of the needle to indicate the direction of a nearby thunderstorm (or maybe it is an OWT, but I like it)
• During vectoring, in the holding or the racetrack, it takes one milisecond’s look at the needle to regain situational awareness. It is so comforting and simple with a pointer always pointing towards your reference.
• When passing the Locator inbound on final approach, you immediately know how accurate you flew by watching how fast the needle turns around
• When you use the needle to fly the beacon inbound part of the final to minimums on a partial panel in IMC and turbulence, and actually break out with the runway in front of you, the smile on your face stays for a while afterwards.

So flying is going to be easier, probably safer and, to geriatric/nerdy/masochist pilots like me, a little bit less interesting, without the ADF.

So, in summary, the arguments for ADF are: (i) legal for the MAPs at many more airfields and therefore useful for IR/IR(R) revalidation; (ii) provides more back-up options in case GPS inop.

And the arguments against are: (i) old (legacy) technology; (ii) space; (iii) power; (iv) weight; (v) cost; (vi) looks naff in a modern panel; and (vi) I’ll hardly ever use it the real world.

IMHO the disadvantages are relatively minor compared to the valuable functional benefits BUT, if WAAS only approaches were common, I couldn’t see myself fitting an ADF.

Would anyone like to guess when GPS overlay approaches might be permitted in the UK?

Well at my home airport EKRK the locator MAP could certainly be navigated using GPS during the long periods the locator was out for repair. The NOTAMs described that in detail. I even did that during my recent FI-IR skill test (I passed). The reasoning was a little foggy though. Something about although the missed is certainly part of the approach, the MAP is not … quite … as it is … or could be … the beginning of an en-route leg. But when authorities approve it and it works perfectly and safely, not many are inclined to explore deeper, apparently.

Regardless of any other factors, an ADF is really no use for

• navigation (range way too small with most NDBs in Europe)
• thunderstorm detection (the effect on the needle is pretty random, and you can’t tell it isn’t pointing at some other NDB instead)

I have asked someone I know in the UK CAA scene whether he can say something, and will post if I hear.

Would anyone like to guess when GPS overlay approaches might be permitted in the UK?

I don’t think that is the Q, because the current-product (not KLN94 ) Jepp IFR GPS databases do already contain representations of navaid approaches. The Q is whether we will ever get a formal (legal) permission to use a GPS instead of VOR or NDB. I can’t see that happening in the near future. There is no move towards this that I have ever heard of, in the EU. Switzerland has something, IIRC.

We are more likely to get new GPS approaches, which is a better way to go because the T-shape is usually shorter than the long outbound and inbound NDB etc approach.

huv wrote:

The last time I used an ADF for navigation other than training/test was in 2001 when I was directed towards an en-route NDB holding in Southern Norway.

I don’t know about Norway, but in some European countries, you can substitute ADF with GPS en-route (but not for approach).

Raiz wrote:

the arguments for ADF are

For me, there are two main arguments for: legal compliance (what exactly would you do if ATC refused your request for alternate missed approach procedure?) and in case I wanted to fly to less developed parts of the world (you think EU is backward? also, the less developed the country, the less I want to risk getting acquainted with their jails/ legal system). I wouldn’t consider ADF as a backup for navigation (approach, yes, but I would have to be rather desperate).

Raiz wrote:

Would anyone like to guess when GPS overlay approaches might be permitted in the UK?

How about never? What UK needs is to stop that NDB nonsense. AFAIK ICAO encourages member states to publish RNAV(GNSS) procedures for every instrumented runway.

Martin wrote:

you can substitute ADF with GPS en-route

I think that was always allowed everywhere, with any approved B-RNAV equipment. But NDB’s serving as en-route fix are disappearing even faster than the ones used for approach.
At the time I found it much easier to dial in a three-digit frequency on the ADF and simply follow the needle than to reprogram the GPS (maybe the thought of using “nearest” on the brand new KLN94 did not occur to me).

I agree with you (Peter and Martin) that the real issue is when the UK will publish RNAV(GNSS) approaches without the stipulation that you need to use the NDB for the MAP. The current situation where a lot of the RNAV(GNSS) approaches still contain such a stipulation is what drives the need to carry an ADF, even if just to be legal for an IR or IR(R) revalidation. This is a very different matter to the question of what one would do in the real world.

Does anyone have any insight into when the UK will publish RNAV(GNSS) approaches for most runways without NDB based MAPs?

Raiz wrote:

Does anyone have any insight into when the UK will publish RNAV(GNSS) approaches for most runways without NDB based MAPs?

When their (paying) customers demand it…