G'day RBF,
I'm old enough to remember a time when instrument approach charts in Australia differentiated between day minima and night minima by 200 feet! I'm not, however, old enough to know whether or not this was originally mandated by ICAO but I suspect not. I do know, however, that the "infinite wisdom" of ICAO came to the fore with Pans Ops 1986, wherein the environmental factors that had to be considered in declaration of DA/MDA did not include night time.
I live in a place where the daylight and darkness graphs have little bearing on reality. The division between these two extremes is neither slow nor subtle. In fact it's more like... one minute there's sunlight and the next minute there's darkness. The cut-off is, of course, due to the effect of mountain ranges which, in general terms, form the backbone of the mainland and all of the larger islands.
Whether or not there should ever have been a compensation for that is open to conjecture. The point that needs to be made, however, is that there is no evidence that the difference has ever contributed to an incident/accident here (at an aerodrome with instrument procedures).
What I'm saying, I guess, is that pilots are given a certain amount of credit for intelligence around here. This is because they are all aware of the problem and well accustomed to it. There isn't a lot of night flying around here and the few places that are available for it have runway-aligned approaches that serve the RWY end that is most likely to need the instrument approach.
Now that's probably a new concept to some folks on here but the fact is that there's 2 kinds of weather - and 2 kinds only - here. One kind blows from one consistent direction and brings (for the most part) reasonably good visual approach conditions. The other kind blows from the reciprocal direction (or close enough to reciprocal) and is more than capable of producing the sort of weather that requires an approach right to MDA.
That's a fairly simplistic summary of a rather complex subject regarding tropical weather, but it's enough to highlight the difference between a place like this and a place like Aspen. I suspect that the problem in the USA is that charter and corporate pilots go anywhere at a moments notice, so to speak, and therefore have little time to familiarise themselves with local conditions at any specific destination.
This is a problem for crews that don't often venture into places such as Aspen. The approach in question was very complex and therefore required crews to devote a great deal of time to briefing it. While that fact should've been enough to alert the crew to the reason for the complex approach, it's easy to understand how this vital clue could be overlooked.
Now then, the FAA system also gives pilots a lot of credit for intelligence, but the simple fact is that there are a lot more pilots, and a lot more charter and corporate companies, in the USA than exist here. And there is much more competition there too. I won't say that the aviation system encourages this because the same would be true here and the accident statistics are vastly different.
I'm not suggesting that the FAA should consider the "night MDA" concept, as previously used in Oz, not even for airports in mountainous areas. It might have made a difference in the prang in question but, overall, I doubt that it would contribute anything other than a lot more missed approaches after the sun has set. I think that, despite the wording of the recommendation, the NTSB has a valid point.
The point probably should be that there needs to be an education program, perhaps compulsory, for pilots to understand that the difference between night and day on some of the (TERPs) circling approaches needs to be understood in the wider context of visual approaches after actual sunset. This is most certainly the most hazardous time, when unlit obstacles cannot be readily seen and will, therefore, be capable of wreaking havoc with any visual approach when visual conditions really don't exist.
The real problem here is, of course, that the design criteria (whether TERPs or Pans Ops) does not require all obstacles to be shown on an approach chart. Instead, the obligation is placed squarely on the pilot-in-command to have made an assessment, based on topographical charts (and local knowledge), prior to using any instrument approach. The difficulty with this is immediately apparent because, after all, who would bother to do so for an ILS approach? Yes, a precision approach is much different to a non-precision approach but the fact is that the design criteria makes no differentiation in the obstacles that need to be shown on the chart.
Large airlines have the capability to make those assessments and the responsible ones do so. Smaller companies - charter and corporate - are unlikely to have the resources for that. Thus it generally falls to the command pilot to do the necessary homework - and to do it without the advantage of knowing the details of the design criteria. Perhaps there will be a "duty of care" responsibility one day, but I suspect that it won't happen any time soon.
Thus, for many such operations, the only safe course is :- when in doubt, don't push your luck - go around and divert. That'd be a bitter pill to swallow, especially in the competitive US charter market but, until technology allows more runway-aligned approaches at difficult locations like Aspen, it's the only safe game to play. In the meantime, a public education program for pilots about the hazards of night visual approaches from circling procedures seems like the only viable option.
There's been no formal education program here but, as previously said, this is an environment where the difficulties are already well known and incorporated into line training. Thus it can be said that there has been an on-going education program here for many, many years with the result that we don't see accidents of this sort. On that basis, I'd have to say that an education program is likely to be successful in reducing the incidence of sad occurrences such as the one at Aspen.