Air New Zealand Flight 901 was a scheduled Air New Zealand Antarctic sightseeing flight that operated between 1977 and 1979. The flight would leave Auckland Airport in the morning and spend a few hours flying over the Antarctic continent, before returning to Auckland in the evening via Christchurch. On 28 November 1979, the fourteenth flight of TE-901, a McDonnell Douglas DC-10-30, registration ZK-NZP, flew into Mount Erebus on Ross Island, Antarctica, killing all 237 passengers and 20 crew on board. The accident became known as the Mount Erebus disaster.
Flight 901 would leave Auckland International Airport at 8:00 am for Antarctica, and arrive back at Christchurch International Airport at 7:00 pm after flying a total of 5,360 miles (8,630 km). The aircraft would make a 45-minute stop at Christchurch for refuelling and crew change, before flying the remaining 464 miles (747 km) to Auckland, arriving at 9:00 pm.
ZK-NZP departing Auckland International,just mere hours away from the crash.
In command of this flight is Captain Thomas J.C,who has over 11,000 hours of flight time. The co-pilot is Greg Cassin,with 8,000 hours of flight time.
The flight deck of this DC-10
The flight had earlier paused during the approach to McMurdo Sound to carry out a descent, via a figure-eight manoeuvre, through a gap in the low cloud base (later estimated to be at approximately 2,000 to 3,000 feet (610 to 910 m)) while over water to establish visual contact with surface landmarks and afford the passengers a better view. It was established that the flight crew either was unaware of or ignored the approved route’s minimum safe altitude (MSA) of 16,000 feet (4,900 m) for the approach to Mount Erebus, and 6,000 feet (1,800 m) in the sector south of Mount Erebus.
The aircraft descending down towards Mount Erebus.
Collins told McMurdo Station that he would be dropping to 2,000 feet (610 m), at which point he switched control of the aircraft to the automated computer system. Outside there was a layer of clouds that blended with the white of the snow-covered volcano, forming a sector whiteout – there was no contrast between the two to warn the pilots.
Moments before disaster
At 12:49 pm, the ground proximity warning system (GPWS) began sounding a series of “whoop whoop pull up” alarms, warning that the plane was dangerously close to terrain. The CVR captured the following :
GPWS: “Whoop whoop. Pull up. Whoop whoop…”
FE: “500 feet (150 m).”
GPWS: “…Pull up.”
FE: “400 feet (120 m).”
GPWS: “Whoop, whoop. Pull up. Whoop whoop. Pull up.”
CA: “Go-around power please.”
GPWS: “Whoop, whoop. Pull-”
The go-around power was immediately applied, but it was too late. There was no time to divert the aircraft, and six seconds later the plane crashed into the side of Mount Erebus and exploded, instantly killing everyone on board.
The final analysis revealed that pilot error was the principal cause of the crash,and attributed blame to the decision of Collins to descend below the customary minimum altitude level, and to continue at that altitude when the crew was unsure of the plane’s position. The customary minimum altitude prohibited descent below 6,000 feet (1,800 m) even under good weather conditions, but a combination of factors led the captain to believe the plane was over the sea (the middle of McMurdo Sound and few small low islands).