Paul Holmes and Erebus

[ampan]

That was definitely what was said to the crew of the flight. They were even given copies of the script as part of their briefing materials. Mahon accepted all this, but said that other materials indicated a route down the Sound and said that “these displays would, not unnaturally, take precedence over the spoken words indicating a direct track from Cape Hallett to McMurdo Station.” (page 60 of the Royal Commission report)

But it would never have happened like that. The pilots would not have sat there thinking ‘eenie meenie’. They would have raised the issue, as they were obliged to do. Mahon’s “displays” were promotional materials, not charts. The only navigational map they were given at the briefing was a photocopy of the inset of this chart:
Antarctic Ross Sea Region | Land Information New Zealand (LINZ) - Toit

If you have the whole chart, you don’t even need a straight edge to tell that a track from Cape Hallett to Mac Station goes over Ross Island. But if you only have the inset, you can’t tell. All the pilots must have left the briefing on the understanding that their track was to Mac Station, but some may well have thought that such a track would take them down the Sound with Erebus to the left.