Desert Dingo -Toss the following thought around in your head: The pilots left the briefing thinking that they would fly down McMurdo Sound direct to McMurdo Station
They could have thought down McMurdo Sound was direct to McMurdo Station?
Rubbish.
Go and review all the testimony about pilots at the briefing estimating how far to the West of McMurdo station the track down McMurdo Sound was going to take them. For more than a year the briefed flight plan had the destination waypoint in McMurdo Sound then returning back to Cape Hallet. The pilots were trying to work out the track and distance for the left turn and visual leg for sightseeing over McMurdo Station.
This was a fundamental factor in the accident. This waypoint was changed and the crew were not told.