Sven Sixtoo
ZD576 did not have radar, as far as I can gather.
Some time ago I posted a great deal on the route as apparent from the stored waypoints, etc.. - of particular note was the selection on 028 on the nav's HoSI course selector which suggested strongly the intention to head out to the route defined by waypoints H to B (028 at the time) after getting to the Mull - this would end up with them handrailing up the clear coastline Isly/Jura and if you are familiar with the Mull coastline you would understand that with the weather that day this was a sensible option as opposed to bumbling up the irregular coast north of the Mull.
With the prevailing local weather on the Mull, it made no sense, nor was it safe, to approach it as closely as waypoint change unless they had a specific reason to do so and some local reference.
There were several attempts to denigrate the significance of way point A, both in inquiries and in the various reports, suggesting that as it did not have so many decimal places (lat, long) that it was not as accurate as the other stored waypoints - I showed that the opposite was true. Whether this untruth repeated so often by the MOD. AAIB, and equipment manufacturers about the waypoints was down to laziness, stupidity, or an agreement to obstruct analysis of the route planning is open to debate.
Just scroll through my posts if you care as I am not bothering to repeat them again now.