Air New Zealand Flight 901 was an international one-day sightseeing flight over Antarctica from Auckland International Airport in New Zealand. On November 28th 1979 the plane crashed into Mount Erebus killing all crew members and passengers on board.
The crew, captain Jim Collins and first oficer Greg Cassin, had not flown to Antarctica before. However, the flight was deemed a straightforward flight. Three weeks before departure the pilots attended a briefing session were they were given the printouts of previous flights to Antarctica. The plan gave the coordinates for the sightseeing trip to Antarctica and across McMurdo Sound.
On 28th November the pilots entered the series of latitude and longitude co-ordinates into the aircraft computer but the pilots did not know that the coordinates had been changed earlier that morning and when they entered into the computer it changed the flight path 45 kilometres to the east.
Around 12.30 pm the McMurdo station gave permission to Flight 901 to descend to 3050 meters and continue visually. Fifteen minutes later the captain told the McMurdo station that he was dropping further to 610 meters. At this point when the captain looked at the navigational system, but the flight 901 was not where the crew or the McMurdo station thought it was. The change in the two coordinates put the flight path across Lewis Sound and towards the 3794 meter Mount Erebus. The captain of the flight faced whiteout because the white of the ice blended with the white of the mountain therefore he could not see the slope on the land. Around 12.49 pm the GPWS gave the pilots a warning but there was no time for them to save themselves from disaster.
11 hours later the crew of a United States Navy plane found the wreckage on the side of Mount Erebus and there were no signs of survivors. After further investigation they found out that the plane crashed into Mount Erebus as a result of the airline changing the aircraft's flight path data without telling the air crew.
Aviation crash video
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Video embedded from YouTube on 14 November 2011
A Primary causation of the Erebus disaster was the crews inability to see rising terrain ahead, namely Mt Erebus and not having sufficient warning both visually and through technology to avoid controlled flight into terrain (CFIT).
The Chippendale report for the New Zealand CAA was clear, the crew had flown below MSA (minimum safe altitude) without correctly identifying their position resulting in CFIT. The Royal Commission of inquiry into the Erebus accident however did not agree solely that this was the primary cause, but merely one of many casual factors, simply the crew would not have flown into the mountain had they known about its location relative to their position or if they could see it.
Research into the accident showed that whiteout is a phenomena prevalent in Polar regions due to the lack of texture and feature caused by snow and cloud. Whiteout accounted for 40% of all US air-force accidents.
Mr Boswell's paper stated that "whiteout is an atmospheric effect which results in a loss of depth perception and is especially common in polar areas". It is a complex process of light diffusion masking undulating terrain, giving it a flat effect. It is even more common where there is a large solid layer of overcast cloud and snow covered terrain and there is no distinguishable horizon. The only effective protection is a large distinctive dark object ahead.
So why did flight TE901 not see Mt Erebus? Simply conditions were perfect. The crew were flying under 8/8 overcast skies with the sun directly behind them at the time of day. The crew were unable to distinguish between the cloud base and the rising terrain until it was too late as the ground proximity warning system (GPWS) was triggered.
Contributory factors to the whiteout were the crews lack of familiarity of operations in Polar regions and inadequate training from Air New Zealand on whiteout conditions. Had the crew known the potential for whiteout conditions despite not knowing Mt Erebus lay ahead, the crew would of be sufficiently alarmed to question their position and current flight profile.
Contributory to the whiteout was the mindset of the crew. Mindset in aviation is both powerful and dangerous.
In this case the crew had attended an Air New Zealand briefing on the 9th November 1979 for the proposed sightseeing flight. The briefing showed that the flight path would take them down McMurdo Sound. Prior to the flight the navigation officer at Air New Zealand moved the last way-point, shifting the final leg from down Mcmurdo Sound to directly over Mt Erebus. Unfortunately the crew were not informed of the decision to move the way-point. This 'mindset' was to prove pivotal as the crew lost visual reference to whiteout but still had no concern for the flight as they did not beleive they were flying towards Erebus but down Mcmurdo Sound.
Aircraft type: McDonnell Douglas DC-10-30
Departure time: 8.20
Date: 28, November 1979
Duration: 11 hour
Destination: Christchurch International Airport
Accident type: Controlled flight into terrain
Knowledge Management Space
- Published date unknown 'Aircraft Accident: DC. 10 ZK-NZP Flight 901'http://aviation-safety.net/database/record.php?id=19791128-0 retrived 23-03-2009
- Air Safety Week (07-03-2007) 'The 1979 Erebus crash' http://www.teara.govt.nz/EarthSeaAndSky/SeaAndAirTransport/AirCrashes/5/en retrieved 23-03-2009.
- Royal Commision. (1981). The Crash on Mount Erebus, Antarctica of a DC10 AIRCRAFT operated by AIR NEW ZEALAND LIMITED 1981. Wellington, New Zealand: Government printer.