Air New Zealand Flight 901

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Air New Zealand Flight 901

Wreckage of Air New Zealand Flight 901 on the side of Mount Erebus, Antarctica.
Summary
Date	28 November 1979
Type	Controlled flight into terrain
Site	Mt. Erebus, Ross Island, Antarctica
Fatalities	257
Injuries	0
Aircraft
Aircraft type	McDonnell Douglas DC-10-30
Operator	Air New Zealand
Tail number	ZK-NZP
Passengers	237
Crew	20
Survivors	0

Air New Zealand Flight TE901 was a scheduled Antarctic sightseeing flight from Auckland International Airport in New Zealand. The Antarctic sightseeing flights were operated with McDonnell Douglas DC-10-30 aircraft and began in February 1977, with this being the 14th flight. On 28 November 1979 the flight crashed in Antarctica, killing all 237 passengers and 20 crew members aboard.

[edit] Flight details

The flight was designed and marketed as a unique sightseeing experience, carrying an experienced Antarctic guide who pointed out scenic features and landmarks using the aircraft public-address system. Such flights had been operating since February 1977. Passengers enjoyed a low-flying sweep of McMurdo Sound, returning to New Zealand the same day. ^[1]

Dignitaries such as Sir Edmund Hillary had acted as guides on previous flights. Indeed, Sir Edmund had been scheduled to act as the guide for the fatal flight, but had to cancel due to other commitments. Sir Edmund's long-time friend and climbing companion, Peter Mulgrew, stood in as guide. The flights usually operated at about 85% of capacity; the empty seats, usually the centre ones, allowed passengers to move more easily about the cabin to look out of the windows.

[edit] Accident

[edit] Circumstances surrounding the accident

Captain Jim Collins and co-pilot Greg Cassin had never flown to Antarctica before, but they were experienced pilots and the flight was considered a simple one. On 9 November 1979, 19 days before departure, the two pilots had attended a briefing in which they were shown a flight plan used by previous pilots on their own flights to Antarctica. The plan gave coordinates for the trip to the continent including a scenic detour around McMurdo Sound. These coordinates, when entered into the plane's computer, would automatically direct the plane through the flight. ^[1]

The coordinates had been entered into the computer by hand years previously, and during this process a single digit had been typed incorrectly. This resulted in the flight plan, which was originally intended to fly directly over Mt. Erebus, being shifted some miles to the west, with no high ground in the vicinity.

[edit] 8:21am-12:30pm: Changes to the coordinates and departure

Collins and Cassin input the coordinates into the plane's computer before they departed at 8:21am NZDT from Auckland International Airport. The flight was supposed to arrive back in Auckland at 6:09pm. ^[2] Unbeknown to them both, the coordinates had been modified earlier that morning to correct the error introduced years previously and undetected until now. These new coordinates changed the flight plan to fly 45 kilometres (28 miles) east of where the pilots intended the plane to fly. The coordinates instructed the plane to fly not over McMurdo Sound, but over Lewis Sound and directly over Mount Erebus, a 4,024 metre (13,200 ft) high volcano. ^[1]

After a smooth take-off from Auckland, about four hours into the flight it was 70 kilometres (42 miles) away from McMurdo Station. The radio communications center there allowed the pilots to descend to 10,000 ft (3,050 metres) and to continue "visually." Air safety regulations at the time did not allow flights to descend to lower than 6,000 ft (1,830 metres), even in good weather. Collins believed the plane was over flat, low ground. ^[1] The flight that day was being operated by the DC-10 ZK-NZP, which was just under five years old.

[edit] 12:30pm-12:50pm: Collision with Mount Erebus

Collins then told McMurdo Station that he would be dropping further to 2,000 ft (610 metres), at which point he switched control of the aircraft to the automated computer system. Unfortunately, at the time there was a layer of cloud that blended with the white of the volcano, forming a sector whiteout. There was no contrast between the two to warn the pilots.

At 12:49pm, the Ground Proximity Warning System began sounding a warning that the plane was dangerously close to terrain. Although Collins immediately called for maximum engine power, there was no time for either Collins or Cassin to divert the aircraft, and six seconds after the warning began blaring, the plane collided with the side of Mt Erebus and disintegrated, instantly killing all on board. Most of the aircraft was smashed into small pieces (with the exception of the empennage). The wreckage burned vigorously in a pool of jet fuel, with much material sinking into the melted ice, which later re-froze.

McMurdo Station attempted to contact the flight after the time of the crash, and informed Air New Zealand headquarters in Auckland that communication with the plane had been lost. United States search and rescue personnel were placed on standby.^[1]

[edit] 12:50pm on: Search and discovery

At 1:00pm New Zealand time, a United States Navy situation report was released, stating:

Air New Zealand Flight 901 has failed to acknowledge radio transmissions. ... One LC-130 fixed wing aircraft and two UH-1N rotary wing aircraft are preparing to launch for SAR effort. ^[3]

New data gathered at 3:43pm was added to the situation report, stating that the visibility was 40 miles. It also stated that six aircraft had been launched to find the flight. ^[4]

At 10:00pm New Zealand time, about half-an-hour after the plane would have run out of fuel, Air New Zealand informed press it believed the aircraft to be lost. Rescue teams searched along the assumed flight path, but found nothing. At 12:55am, the crew of a United States Navy plane discovered unidentifiable debris along the side of Mount Erebus. ^[5] No survivors could be seen. Twenty hours after the accident, helicopters with search parties managed to land on the side of the mountain. It was confirmed that the wreckage was indeed that of Flight 901 and that all 237 passengers and 20 crew members had been killed. The aircraft's altitude at the time of the collision was 445 metres (1,465 feet).

Efforts for recovery following the discovery was extensive, owing in part to the pressure from Japan, from which 24 passengers had been on the plane. The operation lasted until 9 December 1979, with as many as 60 recovery workers on site at a time. Bodies and fragments of the aircraft were flown back to Auckland. ^[6]

The dead included 200 New Zealanders, 24 Japanese, 22 Americans, six British, two Canadians, one Australian, one French, and one Swiss. The remains of 44 of the victims were not individually identified, and a funeral for them was held on 22 February 1980.

The accident is exceptional in that, to this day, controversy exists over the true cause of the accident, and in the amount of responsibility the airline and crew should assume. Public opinion also remains polarised.

The prevailing two opposing theories are listed below, together with their main points.

[edit] Accident inquiries

Page four of the situation report about flight TE901 released by the United States Navy at 12:55am, with the text: "Debris at crash site being blown by the wind. No apparent survivors."

[edit] Official accident report

The accident report compiled by New Zealand's chief inspector of air accidents, Ron Chippindale, was released on 12 June 1980. It cited pilot error as the principal cause of the accident and attributed blame to the decision of Collins to descend below the customary minimum altitude level, and continue at that height when the crew was unsure of the plane's position. The customary minimum altitude prohibited descent below 6,000 feet (1,830 metres) even under good weather conditions, but a combination of factors led the captain to believe the plane was over low, flat ground, and previous flight TE901 pilots had regularly flown low over the area to give passengers a better view.

[edit] Mahon Inquiry

Due to public demand, the New Zealand Government announced a further one-man Royal Commission of Inquiry into the accident, to be performed by Justice Peter Mahon.

Mahon's report, released on 27 April 1981, cleared the crew of blame for the disaster. Mahon said the single, dominant and effective cause of the crash was the changing of the aircraft's navigation computer co-ordinates to route the aircraft directly towards Mt Erebus without the crew being advised. The new flight plan took the aircraft directly at the mountain, rather than along its flank. Due to whiteout conditions, "a malevolent trick of the polar light", the crew were unable to visually identify the mountain in front of them. Furthermore, they may have experienced a rare meteorological phenomenon called sector whiteout which creates the visual illusion of a flat horizon far in the distance. Mahon also found that the radio communications centre at McMurdo Station had authorised Collins to descend to 1,500 feet (450 metres), below the minimum safe level.

Mahon controversially claimed airline executives engaged in a conspiracy to whitewash the enquiry, famously accusing them of "an orchestrated litany of lies" by covering up evidence and lying to investigators.

[edit] Appeal to the Court of Appeal

[edit] Appeals

Air New Zealand appealed against Mahon's findings to the Court of Appeal, which set aside the costs order against the airline. Mahon in turned appealed to the Privy Council in London. His findings as to the cause of the accident, namely reprogramming of the aircraft's flight plan by the ground crew who then failed to inform the flight crew, had not been challenged before the Court of Appeal, and so were not challenged before the Privy Council. His conclusion that the crash was the result of the aircrew being misdirected as to their flight path, and was not due to pilot error, therefore remained. But the Board held that Mahon had acted in excess of his jurisdiction and in breach of natural justice by going on to make findings of a conspiracy by Air New Zealand to cover up the errors of the ground staff. In their judgment, delivered on 20 October 1983, the Law Lords dismissed Mahon's appeal and upheld the decision of the Court of Appeal. Aviation researcher John King wrote in his book New Zealand Tragedies, Aviation:

They demolished his case item by item, including Exhibit 164 which they said could not "be understood by any experienced pilot to be intended for the purposes of navigation" and went even further, saying there was no clear proof on which to base a finding that a plan of deception, led by the company's chief executive, had ever existed.

"Exhibit 164" was a photocopied diagram of McMurdo Sound showing a southbound flight path passing west of Ross Island and a northbound path passing the island on the east. The diagram did not extend sufficiently far south to show where, how, or even if they joined, and left the two paths disconnected. Evidence had been given to the effect that the diagram had been included in the flight crew's briefing documentation.

It is important to emphasise that by 'his case' King was referring to the Mahon's case for a cover-up, not the case that the crash was not due to pilot error.

[edit] Legacy of the disaster

The crash of flight TE901 remains New Zealand's deadliest disaster, followed closely by the Napier earthquake. The small size of New Zealand (at the time, the population was under three million) meant that a sizable percentage of the population was affected personally or by association.

A wooden cross was erected above Scott Base to commemorate the accident. It was replaced in 1986 with an aluminium cross after the original was eroded by low temperatures, wind and moisture.

Almost all of the aircraft's wreckage still lies where it came to rest on the slopes of Mt Erebus, under a layer of snow and ice. During warm periods when snow recedes, it is still visible from the air.

For failing to deliver the result Prime Minister Robert Muldoon expected, Mahon remains something of a controversial public hero.

In 1980 Air New Zealand decided to replace its DC-10 fleet with Boeing 747-200s. In 1981-1982 all DC-10s in the Air New Zealand fleet were sold overseas and replaced by 747s.

A television miniseries, Erebus: The Aftermath, focusing on the investigation and Royal Commission of Inquiry, was broadcast in New Zealand and Australia in 1988.

The phrases "Whoop Whoop Pull Up", (the automated ground proximity warning, recorded on the black box) and Mahon's "An Orchestrated Litany of Lies" have entered New Zealand popular culture.

[edit] See also

• Accidents and incidents in aviation
• Ansett New Zealand Flight 703
• New Zealand National Airways Corporation Flight 441

[edit] References

[edit] External links

• Aviation Safety Network: Transcript of flight 901
• US Navy Situation Report
• New Zealand Ministry of Transport Official Report parts 1, 2, 3, 4, 5, and 6 (all PDF)
• Accident details at planecrashinfo.com
• The original brochure advertising Air New Zealand flights to Antarctica
• Judgments of the Court of Appeal of New Zealand on Proceedings to Review Aspects of the Report of the Royal Commission of Inquiry into the Mount Erebus Aircraft Disaster, available freely at Project Gutenberg