To the east of Ben Cruachan it is highly likely that the weather was perfectly reasonable VFR. In the lee of that ridge running down the east of Loch Linnhe it would have had a very low ceiling. To the west more typical of the Tiree conditions
Over Tiree where there is a single area of high ground and the rest of the island is about 20ft high it would have been reasonable to descend over the sea and sneak in. These conditions are not unusual on the west coast and it is possible the pilot was familiar with them - or equally they were not. But being natives of the island and IMC rated? Likely they were familiar with the typical conditions.
Dar, it may have been my despair moment, that prompted you to start this new thread. I am not digging at the poster, but I am in despair that this kind of thinking prevails. There is just so much wrong here.
1. I have been lost, five miles from my local airport, in a 400 overcast. What I see very often, that at different levels, particularly under low cloud base, all of the tell tale local landmarks change perspective. In fact, the landscape, and the visual perspective, changes markedly at different levels.
2. With a low cloud base, there is generally a low forward viz.
3. Knowing the locale, scares me senseless. My view it creates a false security. The, I can find my way in/out', mentality.
4. Within mountain terrain, I defy anyone, who happens to "pop" out from cloud, to know where they are. Valleys tend to look the same.
5. The flight in question, should never have started with destination forecast conditions. Over the sea let downs, to, in this case 300', can really only end one way, unless Lady Luck is really watching over you.
6.I do not think ppl trainees are being taught any of this. It does appear that experience is the teacher, and that individuals find out, generally the hard way, what it is really like to be caught in this stuff.
7. I also get concerned on longer flights. Take off, cruise ability, and approach landing weather, must ALL be taken into consideration. Weather, spooky this, changes, not only with the prevailing forecast. The west coast of Scotland, in particular, can have some very localised weather, therefore, an achievable plan B must always be available.
8.My personal experience is that as my ratings expanded, and my Instrument flying got more involved, then my own minima, increased. I think that as a direct result from being in such IFR conditions, you soon realise what a potential disaster could unfold, unless you really were current and on top of your game. The days of winging it, certainly for me, are over. Every flight, over any distance, is thoroughly and totally planned, the most important being weather.