I have never understood the VMC into IMC helicopter accident
It's far easier to understand than a fixed wing event actually, helicopters have the advantage of slowing down and be on the tree tops creeping along at just a few knots. Don't ask how I know, a situation a lot, I repeat, a lot, of helo pilots have faced. Question, what minima additive you place on a NDB approach when your helo is slinging a load on a 200' long line having gone unwanted IMC in the mountains of New Guinea.