If during the briefing you are shown:
In the Antarctic pack
- GNC21N a large topographic chart (105 x 145 cm) showing New Zealand, Tasmania and Antarctica. No flight plan track lines on it.
- NZMC135 another large topographic chart showing Antarctic coastline (Victoria Land) and a McMurdo Station inset. No flight plan track lines on it.
- Strip Chart (annex 1) Topographic chart showing military tracks, including the two down McMurdo Sound to Byrd waypoint and left turn to McMurdo Station.
- (DOD Strip chart Exhibit 165) Shows military route down McMurdo Sound to Byrd waypoint then left turn to McMurdo Station. Similar to Strip Chart (annex 1) but without topographic detail, just some bits of the coastline more than 100 nm from McMurdo Station.
- RNC4 Radionavigation chart showing (among others) direct track from New Zealand down McMurdo Sound to Byrd waypoint where the track ends. Flight plan track not shown.
- The famous Exhibit 164. An ANZ Nav department chart with no topographic detail but showing the two military tracks down McMurdo Sound to Byrd waypoint ending at a common waypoint with the track from New Zealand via Cape Hallet.
- A copy of a previous flight plan (flown 2 days previous to the briefing) which has the final leg from Cape Hallet down McMurdo Sound to McMurdo waypoint and return to Cape Hallet.
In the passenger pack
- Passenger map (exhibit 47) Clearly shows track down McMurdo Sound although not in great detail.
Then the slides
- Map of proposed route (Exhibit 197/8) showing track (you guessed it) down McMurdo Sound.
- Slide showing Mt Erebus “to left of track”
- Slide showing Erebus to the left “on approach from Cape Hallet” (They got this wrong. It was actually Mt Erebus viewed from the south)
- The slides appear to be taken with the aircraft over a flat surface of ice or snow, with a mountain in the distance. ( i.e. as it would appear if taken from somewhere over McMurdo Sound.)
OK, I’m starting to notice a pattern here.
Maybe the track runs down McMurdo Sound!
This is not particularly brilliant briefing material. The final waypoint (McMurdo) on the flight plan is not shown on any of the charts. So let’s locate it ourselves. The Byrd waypoint is on a lot of the charts and is in the same area.
Byrd is S77.30.0 E165.00.0
McMurdo is S77.53.0 E164.48.0
That’s 23 minutes (or 23 nm) further south and 12 minutes (or - stuffed if I know – sin or cos something or other, but less than 12 miles) further west.
Still not much use, but RNC4 shows Byrd in the middle of McMurdo Sound, and <looking at the inset to NZNC135> that is about “here” which makes McMurdo about “here” (still roughly the middle of McMurdo Sound).
So, after a left turn, the distance to McMurdo Station will be about (insert guess- Simpson & White got 10 nm, Gabriel got 50 nm.) Maybe I should do some home work and accurately plot this waypoint before I do the flight?
Now, on the day of your flight you get the same documents, with only 2 digits transposed on the flight plan, and you are expected to know that the track is (and has always been) over Mt. Erebus!
Give me a break! 
Some objections:
- There was the HI-NDB-A chart, and the NDB would have to be the final waypoint.
Yeah, fat lot of good that is. The NDB was withdrawn from service. Let’s do a let down using a non-existent aid.
- Then there is prospector’s favourite memo. NDB withdrawn. ASR monitoring requirement removed. (Quite smart that. The radar can’t see you while you are overhead doing a let-down anyway). So it is VMC descent only and in specified sector within 20 nm. Just how are you supposed to do that? Got the DME from the TACAN, but no azimuth guidance from any ground aid. Maybe that is the reason the briefing officer said to hell with that mission impossible, and you are cleared to descend visually to anything McMurdo ATC clears you to.
- Should have verified waypoint by plotting on a chart. No. The company SOPs are to check waypoint entries against flight plan data.
- Should have used the aircraft radar to verify position. No. The company SOPs prohibit using weather radar for navigation.
- Should have verified AINS accuracy before descending. No. There are 3 of the buggers for a good reason.If one develops an error it gets out-voted by the other two. Three IRSs are quite accurate, thank you. (The C141 required radar identification before his IMC descent because he had only 2 inertial systems and so was not error proof). Anyway, a VMC descent, by its very nature does not require a position fix. (Thank you Brian)
Right. Tell me again why Collins was told and should have known his track was directly over Mt Erebus, and I’ll ask you, if he knew that, was he insane or just suicidal when he engaged NAV mode when he was down at 1500 feet altitude with less than 10 miles to run to the side of a 12,450 foot high mountain.
The only rational conclusion to make is that Collins was never told anything about a track over Mt Erebus, and had every reason to believe it was down McMurdo Sound.