Tec, BOAC was right to correct you, pls read the post again, it's not that hard: there was a route planned by another officer (RN) that would have done the job and would have been the ideal route if WX had been too bad for crossing the Antrim Hills or going anywhere near the Mull;
this route was Aldergrove - H, thence to B;
I posted a long time ago an explanation for the odd letter sequence - I'll leave you to look that up yourself;
because of the requirement for the Chinook to be capable of flying on one engine for this sortie, the all up weight limit left this flight fuel critical - all the sums had already been done Ald-H-B and so provided they did not extend the path beyond this planned length, they could have an excursion - Ald-A-then across as a parallelogram as per the schematic got them to the Mull without any change to fuel calcs nor schedule.
Perhaps I should have done two separate schematics - or labelled a point where the line from the Mull going NW intercepts the 028 track from H-B - they would have been joining the H-B track somewhere near one of the islands (Islay or Jura, cant be bothered to check now).
Tec, if you read my posts, I have always said that they could not have done anything else BUT do a straight line at high cruise speed on 027 from Ald to waypoint change - you can do better than this.
Chugalug et al
What is it you do not understand about analysis of the known data pointing to a planned approach viewed with regard to practical airmanship in the prevalent conditions deducing that they had to have had a local reference of a certain type? Further, that such equipment was denied strongly but such was the confidence in the analysis that this line was investigated and later it was found to have been fitted.
Is the concept of QED familiar to you? - in science it rather proves the theory.
