Walter.......
...the request was for a list of co-ordinates you used........a diatribe about headings does not show anything....
..plotting all the GPS locations from the RACAL report , Aldergrove , waypoint change , last steering update , powerdown and the last unprocessed location from the Trimble GPS itself......you can see that they are all in a straight line.....Robin....
....plot them on a map or use software , I prefer a Garmin programme which I have , but Google earth will show the same......
rgds Robin........