Shy
Agree entirely that the 1000 ft above anything within 5 miles rule for MSA is a definition from a bygone age and quite inappropriate now. A modern IFR equiped helicopter is sure to have at least one GPS with RAIM and frankly I would trust the accuracy of this more even than a pressure altimeter - I've had failures of these and unlike the RAIM GPS there can be no warning indications. But it's not just believing the GPS - it's often very easy to verify it's accuracy to say at least a mile by cross referencing with a radar fix and VOR/DME position, particularly at Peasmarsh with the LYD next door.
I'd guess the MSA at this Peasmarsh site might be 1300ft QNH - a quite ridiculously high MDA for this site. MSA is fine and very appropriate for knowing your safe cruise altitude en route, when you're not focussed on a specific location, but it would be very and unnecessarily restrictive to IFR helicopter operations doing let downs where there is no published approach.
And let's be clear, this incident had nothing to do with the crew believing there were somewhere they were not - their GPS was accurate and they were where they thought they were, horizontally at least. It happened because they tried to fly visually without adequate references and lost orientation. Agree with Shy again what they should have done is not tried to cling on to vague visual reference at night, but after the initial approach down to a height of 300ft failed, simply gone around and climbed straight ahead back into IMC. And then gone to Lydd.
This was an incident essentially about loss of control in IIMC, not from the initial let down. They probably descended too low on that, but that phase didn't cause the incident - which was clearly very close to being Haughey style catastrophic.
Crab - do you still really think IMC let downs should never be below MSA in IFR helicopters? I guess if you have rarely operated in such a way you have little experience to draw on.
Of course what we really want is much faster and simpler CAA approvals of submitted formal IMC let down procedures.