Yesterday I was in a meeting with most of the people in the CAA who are likely to have an opinion on this (ie people from Flight Standards, Operations and Legal, as well as management) and there was a view, which no-one contradicted, that it is perfectly acceptable to request from ATC an alternative MA procedure which does not require the ADF.
And, when you think about it, 90% of approaches where an MA is expected, whether in training or in bad weather, ATC will give a different or non-procedural instruction, like “in the event of a missed approach climb on runway heading to 2000’”
So, if you are going to Cambridge or Gloucester, or somewhere where the NDB is specified in the MA, and they haven’t already given you an alternative, you simply say “I am not equipped with ADF, request alternative missed approach instructions.”
Fine, but nobody is going to do that anyway. Everybody (except maybe A&C) is going to fly it using the GPS.
Timothy said:
Yesterday I was in a meeting with most of the people in the CAA who are likely to have an opinion on this (ie people from Flight Standards, Operations and Legal, as well as management) and there was a view, which no-one contradicted, that it is perfectly acceptable to request from ATC an alternative MA procedure which does not require the ADF.
And at Kirkwall, which is non-radar, that would still be simple: fly the MAP as for the VOR or ILS IAPs…
boscomantico, while you are quite right, the point I was making was about the legality. If anyone really is concerned about enforcement action for not having an ADF, they can use that alternative form of words.
A_and_C wrote:
No one has yet been able to tell me how they are going to find the missed approach holding point if their GPS fails for some reason.I can’t understand why those of you who own aircraft are so reluctant to carry an ADF box, they are light, reliable, don’t take much panel space and some of them even have Superflag output to make them safer for your EFIS systems.
You’re not going to have even started an RNAV LPV approach with a failed GPS, so having to hold is a moot point, and the probability of the GPS failing just as you need to fly the missed approach is infinitesimally small. If it were me I would just use Skydemon to find the holding point. The iPad has a dual GPS/GLONASS receiver so it would take both constellations to go down at the same time, and if that happens I’m probably more worried about the nuclear bombs that caused it than flying some NDB hold.
ADF boxes do take panel space. Unless you’re flying a cabin class twin, panel space is absolutely at a premium and given the choice, an ADF is pretty much at the bottom of the list if it means not having one of the following: VOR/DME receiver, Strikefinder, fuel/engine monitor, second GPS etc. ADF is also inherently unreliable – it is affected by coastlines, lightning strikes etc. Unless you can afford an EFIS equipped plane, the ADF is also more workload to use than pretty much any other electronic navaid.
It is certainly a weird attitude that says “I trust my GPS to point me at the ground at 200’ in IMC, but I don’t trust it to find my way back to the overhead at 2000’”
Having said that, I can’t agree that the ADF is a high workload device. Yes it has some horrible errors and quirks, not only coastlines, mountains and CBs, but it’s own errors like dip and quadrantal; but in terms of display, I have to say that it is the simplest of all the instruments we have to interpret. An unequivocal “It’s over there”.
I fly glass, I teach on glass. I have taught on most of the glass setups available. They are all subject to massive interpretation problems. I have seen many more looks of bewilderment with glass navigation than single needle ADF.
Timothy wrote:
I have to say that it is the simplest of all the instruments we have to interpret. An unequivocal “It’s over there”.
It’s simple if all you need to know is “it’s over there”, but often there’s a need to fly a particular course. Those of us in the hand-to-mouth end of general aviation without RMIs or other fancy stuff have to twiddle the card manually and potentially be doing mental arithmetic if we want to fly an approach or a hold based on one, and manually correct for wind, which is much more workload than just setting the OBS for a VOR receiver, or following a magenta line on an IFR GPS, particularly if you’re single pilot.
The one think I have learnt in my 40 years in the aviation business is that when things start going wrong it has a habit of going wrong all at once, GPS signals are very weak and so are subject to being blocked by interfearance both human & atmospheric so this is why total reliance on GPS is unwise.
The airline business is into multi sensor navigation in a big way with the primary back up to GPS being DME/DME. This is the favoured option as for normal navigation there is no difference and for approaches the limits are much the same as NP GPS approaches.
The one chance that GA had to go multi sensor was totally ignored in the scramble to go all GPS, so having ignored the logical multi Sensor option the only way to get an aircraft back into the safe area of the missed approach holding fix is to revert to navigations dark ages and use the ADF or VOR.
I do realise that my Luddite ways will be seen like a red rag to a bull by some of the pro GPS crowd in not just defending ADF but DME as well ……. But I don’t intend to set myself up for a pilot generated CFIT?
The ADF is great if, in a dire emergency and totally overloaded, you want an instant clue where the beacon is.
But it is an absolute bastard to use for tracking radials/bearings while correcting for wind offset. That’s why all the masochists purists in the CAA and FTO business love the ADF. It’s mastery is the ultimate demonstration of your balls (apologies to any girls who had to do this) being truly connected to the aircraft.
Glass cockpits confuse the hell out of all but really current and clever pilots, as do modern avionics generally, but they are here and people don’t get a choice.
On a practical note, the NDB will be with us “for ever” because it is the cheapest way to enable commercial (AOC) flights to some little airport. Most AOC flights have to be done under IFR (officially) and that requires a navaid, and an NDB is the cheapest navaid. I think you can get one for about 10k, especially used, plus maybe 2-3k p.a. for a service contract. A VOR or an ILS costs 10x to 100x more. Most low-end AOC ops cannot fly a GPS approach because their business model is based on shagged out planes and running them into the ground. In fact the vast majority of airlines cannot fly a GPS approach (not approved in the ops manual). But it doesn’t bother them because all airliners and most bizjets can fly a virtual ILS to anywhere, via an FMS-generated “ILS”. Accordingly they don’t need LPV – except for the lower minima.
Peter wrote:
But it doesn’t bother them because all airliners and most bizjets can fly a virtual ILS to anywhere, via an FMS-generated “ILS”.
?!?
What’s a virtual ILS?
