AINS-70 Navigation
Ampan wrote in #523, "The crew thought they were identical, but they were not. It may be that the check was performed using the earlier flightplan. But they shouldn’t have used either of the printed flightplans. The digits on the printed flightplans did not tell them where they were going. The digits that told them where they were going were those that had been entered (my bold) into the AINS before take-off, and that’s where they should have looked."
That makes it sound as if some anonymous person or device had entered the waypoints into the AINS-70. Remember, there was no company route for Antarctica on the AINS-70 flight data tape. Waypoints had to be entered manually, just as in any INS of the day.
I have never seen or heard of an airline operation where manual waypoints are entered by anybody other than the flight crew. That person would have used the flightplan as source of the waypoints' lats/longs.
When another of the crew verified the correctness of the waypoints, he would have used the same flightplan. If they had used an earlier flightplan, they would have been steered clear of Erebus.
Having a National Geographic map of Antarctica onboard for plotting their course - would have made the difference.
GB