On 26 June 1968, the United States released a “Policy Statement with Regard to Support of Foreign Government, Commercial and Private Aviation in Antarctica.” This document set down the limitations within which aviation activities over Antarctica would need to operate. Essentially it stated that, because of the limited nature of resources available, the US would only support government-operated aircraft operating as part of the US’s scientific endeavours in Antarctica; and commercial or private aircraft operations that would ‘clearly further the interests of the United States Antarctic program.’ 39
The decision as to whether a proposed flight would “meet proper safety standards” was invested in the Commander US Naval Support Force, Antarctica. This suggests that the flights proposed by Air New Zealand and QANTAS would have come under such scrutiny. Interestingly, in the post-Erebus inquiry, the Chief Traffic Controller and MAC Centre Supervisor at McMurdo Sound, Warrant Officer CR Priest, stated in his affidavit:
“We were not aware at the time of the sector within which the Air New Zealand DC10 flights were said to be required to fly. This required sector as now identified to me by representatives of the Royal Commission would in my opinion have been absurd. Any radar controls contemplated by those planning such flights for purposes of assisting in descent manoeuvres would have been virtually impossible… There could be no adequate ground based control should it have been required. I re-emphasize that to the best of my knowledge, Operation DEEP FREEZE was unaware of any officially approved Civil Aviation Division (CAD) or Air New Zealand flight plan or descent approach. However, had such a flight plan or descent approach been provided for DEEP FREEZE consideration and had DEEP FREEZE agreed to provide radar let-down assistance, I would have regarded such a plan as extremely ill-advised for the reasons stated.” 40
Another passage of interest in the US policy statement is a discussion around the unreliability of altitude-sensing devices in the Antarctic. In hindsight, the document’s words are a dark portent: “While considerable reliance must be placed on radio and radar altimeters, pilots must be constantly aware of the altitude errors inherent in emission-type altimeters when used over snow or ice surfaces. Radio and radar altimeters must be constantly monitored while operating in conditions of poor surface and horizon definition because gradual rises of upward sloping terrain masses frequently cannot be detected visually.” 41 The document also makes reference to “illusions and mirages caused by whiteout conditions.”
So, almost nine years before the first Antarctic overflight by QANTAS, the American authorities in Antarctica had expressed concern at the increasing levels of aircraft activity there. However, rather than ban or restrict such operations, their response was to draw up a set of guidelines – and set in place procedures – for the safe operation of a variety of aircraft.
And the New Zealand scientific community, at least, seemed satisfied with the preparations that had been made. RB Thomson, Superintendent of the New Zealand Antarctic Division (and subsequent commentator on several Antarctic flights) stated that “if such overflights were conducted well within the capacity of the aircraft and all normal flying regulations and procedures strictly observed, such flights would be no more hazardous than the flights that occur daily across the north polar route… such as the direct flights from Anchorage to Copenhagen.” Given that he believed the “impact of sightseeing flights over Antarctica is insignificant” he felt “inclined to support them.” 42