." Forget about assumed tracks and so on, but can we also agree that if the a/c had been about 500 yds to the left, (confusion between lighthouse compound and fog signal compound?- just a theory) it would have cleared the hill ahead with around 200 ft to spare, and no-one would then ever have known about this most grievous breach of airmanship ie flying blind over hills.
Sorry, JP, I didn't realize this was a serious question aimed at me.
If you are suggesting that the crew were actually intending to rely on TANS to take them in IMC to an accuracy of 500 yds within 200ft of terrain then you are indeed suggesting reckless folly and gross negligence.
I find such a plan quite incredible. Ludicrous.
You also say:
Entirely agree your "Why the chinook continued more or less straight into the Mull, instead of turning left to follow the coast below the cloud will never be known without doubt."
At last agreement, and by definition you can no longer support the case for the verdict of Gross Negligence, which relies on just such a standard of proof.