Jafa:
Didn't do a track check out of the last waypoint (Mt Hallet?)
Relied on the INS which they knew at that stage could have been 15 miles out.
What was the weather radar picture?
It's been a long, long time since I looked at this. Isn't Hallet some 200 miles back? A 10 mile or whatever difference in next wpt would be on the order of 3 degrees. Is that enough to trigger concern? There might be that much error reading the HSI.
The AINS-70 did triple inertial mix before the term was invented by Litton in their later LTN-72. From the 5 hours or so since last AINS position update near Christchurch, the position error was about 1.5 miles. ANZ and other KSSU configuration DC-10 operators had always seen that kind of accuracy. The crew had little reason to question the Nav system, and they obviously never checked the lat/long in their flight release against a good chart. In fact, it was the over-reliance on the AINS by the pilots and the company that resulted in complacency.
Whose responsibility was it for the pilots to have good charts appropriate for the route? The QF 747s flying Antarctica at that time didn't have AINS-70, just triple INS. What charts did they have as backup?
The RDR-1F Wx radar in the ANZ DC-10 fleet would paint only a thin line when presented with a steep mountain from 1500 feet altitude. It would have been useful before they descended, however.
GB