Chinook
Flipster & Co. No-one will ever know why they pressed on instead of turning up the coast. But the fact is that they should not have been there, close to the coast, in those conditions at all.
The most likely explanation of why they entered IMC over those notorious and very dangerous hills is that they were about 500 meters to the right of the track that would have taken them over the lighthouse and thus over the hill-top with around 300 feet to spare; but those 500 yards to the right of track and thus over the (somewhat similar looking) fog station site meant that the hill-top in front of them was 300 feet or more higher than they expected. They mistook one for the other. Have a look at the map and at the contours of where they crashed.
But in the end it does not matter why they did not turn away, they did not; and it had nothing to do with being distracted by a fly in the cockpit(both pilots!!!) - as has been seriously suggested, nor with a false beacon laid on the hillside by the IRA - as has also been seriously suggested in this thread.
And, just by the way, in order to deflect any further insults from those who oppose the final findings, I am nothing to do with MOD, nor with Day- I do not recall ever meeting him, nor WRatten - who I happen to have met a couple of times, nor with with the numerous Air, Flight Safety, Legal and other staff officers who supported their views at Group, Command and MOD levels. So may we please have less of the personal attack mode, and a little more objective examination of what happened. Regars to all those of goodwill. JP