And that was the reason for making the descent requirements as they were.
If they had of been complied with there was no way the flight could have impacted on to Erebus
prospector, I have every reason to believe the crew fell foul of the whiteout condition presented to them at their 12 o'clock. 3 nautical miles (NM) prior to impact photographs show that the lateral visibility was at least 12NM from their 1,500 foot altitude. NZ's requirement was 20K vis (10.8NM). In my reading I don't see anywhere that they failed to maintain VFR below 16,000, but stand to be corrected.