The flight plan that had been approved in 1977 by the Civil Aviation Division of the New Zealand Department of Transport was along a track directly from Cape Hallett to the McMurdo non-directional beacon (NDB), which, coincidentally, entailed flying almost directly over the peak of Mount Erebus. However, because of a typing error in the coordinates when the route was computerised, the printout from Air New Zealand's ground computer system presented at the 9 November briefing corresponded to a southerly flight path down the middle of the wide McMurdo Sound, approximately to the west of Mount Erebus. The majority of the previous 13 flights had also entered this flight plan's coordinates into their aircraft navigational systems and flown the McMurdo Sound route, unaware that the route flown did not correspond with the approved route.