I have been following this thread and have learnt a lot about radar theory and EGPWS use, so I thank you fellow pilots out there for teaching me some new tricks. If I can maybe raise a few points ( I am a SAR pilot with similar systems in my aircraft type):
1. Many posts have been critical of the descent profile and why they made such a long flight at 200ft. I suspect that because the APBSS approach is not an IFR procedure, the crew realised they would have to get visual below the cloud (300-400ft) to then track toward Blacksod via the APBSS guidance (I would love to know the purpose of the APBSS, VFR vs IFR, what is it there for?). To do this descent, many operators have a 'no closer' clause in their OM so I would think they have to descend clear of all land (looking at the map, it might be 5-10nm) to get visual below cloud before they then would be allowed to turn back towards their fuelling point. If they were any higher, they would have been IMC and since there appears to be no IFR arrival plate to Blacksod, then this would not have been feasible.
2. NVG would have definitely been a final safety feature as they (I believe) would have seen the large rock ahead of them. I have flown a lot of NVG over water and even on the darkest nights, the contrast should have alerted a scanning pilot as to their danger.
3. Some people have mentioned lack of talk on the CVR as complacency. I don't believe this for a second as this crew were at low level, in the dark and in an unfamiliar area. I bet their arousal level was through the roof.
I look at this sad and preventable accident and see much to learn on a personal and organisational level. I am not going to armchair quarterback the crew as I am honest enough to think that some of the decisions made would have been the same if I was in the aircraft. I think the basic problem was the crew did not realise the BLKMO was 300ft high and for some inexplicable reason, they did not see it on radar. If only Blacksod had an IFR RNAV approach, this accident would not have been occurred and four fine persons would still be doing the job they loved.