In the aftermath of the tragic accident on Mt Erebus, Captain Alwyn Gordon Vette quickly began to consider that the crew was not to blame. Captain Vette thought it was inconceivable for the highly professional DC-10 crew to fly into a mountain without an unlikely level of simultaneous incompetence. Captain Vette did not accept the cause of the crash was pilot error.
While it seemed that few of his fellow pilots, aviation authorities or company management of the time were interested in investigating the possibility of unknown factors, it was not long before Captain Vette’s search for the truth of what happened at Erebus became his mission and his measure. Soon Captain Vette found himself virtually alone on his quest for the truth surrounding the fate of TE901. That fate would lead him to ground-breaking findings, discussions with international experts - and cost his career.
Captain Vette’s investigative efforts were part of the public debate and demand that precipitated a Royal Commission of Inquiry, headed by the forthright High Court Judge Peter Mahon QC, six months after release of the official accident report. Air New Zealand management at the time was avoidant and disinterested in Captain Vette’s research, so he presented it to the Royal Commission, and it was accepted.
Justice Mahon dug deeply into the planning and execution of the flight including testing Captain Vette’s hypotheses and evidence with international experts before using Captain Vette’s work as the basis for the Commission’s Report. Justice Mahon’s findings were eerie in their implications for air crew: even with the most modern instruments available, nature can still spring traps beyond reasonable prediction and even the best-run airline can become the victim of organisational weakness that allowed a simple computer error to have tragic consequences. It was a long and stressful year before Justice Mahon presented his extensive findings which supported Gordon’s provocative and original theories about the tragedy of TE901.
Captain Vette’s Hypotheses
Captain Vette developed three primary hypotheses about the causes of the accident:
- The destination waypoint near the southern end of McMurdo Sound was shifted more than 25 miles to behind Mt Erebus without notifying the crew. Instead of a safe flight path up the clear sea ice of McMurdo Sound (in accordance with their previous map preparation) the crew keyed in a route to their own demise.
- The three independent navigation systems confirmed that they were on track in accordance with the grid computerized flight plan held in the company computer.
- The visual counterfeit of Lewis Bay for McMurdo Sound, a powerful illusion caused by sector whiteout, confirmed the mental set of the crew, who saw exactly what they expected to see right up to impact – a flat white plateau of sea ice extending to the far distant horizon with textured cliffs on each side with no snow showers between them and the apparent far distant horizon.
When Justice Peter Mahon went to Antarctica to research 'Sector Whiteout', he was given a perfect illustration of how a mountain could disappear before the eyes a professional flight crew. The below photographs were taken in sequence on the helicopter ride up to Mt Erebus in 1980.
Note in picture 5 the significant difference in visual conditions.
Picture 5 - 'Sector Whiteout'