The Mt Erebus Disaster

By: Jay  Janarthanan for Internal Assessment AS91230

What Happened?

On 28 November 1979, Air New Zealand flight 901 left Auckland Airport for Antarctica carrying 237 passengers and 20 crew. All passengers and crew were killed instantly that day at 12:50pm when their aircraft collided with the slopes of Mt Erebus, on Ross Island, Antarctica. A timeline, based on the Civil Aviation Report and the Royal Commission of Inquiry (primary sources) has been compiled. The timeline below explains how such a tragedy occurred:

14 Months Prior to Accident
Air New Zealand computerizes its flight plans. In doing so, an operator creates a minor error in the flight plan by typing a 4 instead of a 6 into the flight plan of Air NZ Flight 901, sending it down McMurdo sound. Nobody notices that it is an error as the resulting flight plan sent the aircraft 30 miles west so that it ran down the flat sea ice of McMurdo sound rather than over the active volcano, which was logically safer.
  9 November 1979
Captain Jim Collins and First Officer Greg Cassin attend a route qualification briefing to be briefed on the rules and guidelines of the flight. They were given their navigational co-ordinates at this briefing and were told that the Instrument Flight Rule route would take them over the McMurdo sound.
 (Evening) - 27 November 1979
Captain Jim Collins plans his route for the antarctic flight with his daughters observing. He is planning using the information given to him at the briefing 2 weeks prior, and plots a chart that takes the aicraft down McMurdo sound. he never mentions Mt Erebus to his daughters.
 (Early morning) - 28 November 1979
The Air New Zealand navigation section changes the flight plan of Flight 901, believing they are making a minor adjustment. However, due to the typing error 14 months ago, the route had now shifted 27 nautical miles to the east, meaning the aircraft was now flying directly above Mt Erebus.
 (Morning) - 28 November 1979
The flight crew receive the amended co-ordinates and type them into the computer without question or verification. They have not been told of the changed co-ordinates and do not double check as it was impractical to do so in the confines of the cockpit, as well as the fact that Captain Collins had planned his route the night before.
 8:27am - 28 November 1979

Flight 901 Takes off from Mangere Airport bound on the sightseeing trip to Antarctica.

 (during flight)

Mac Centre (McMurdo Air Traffic Control) advises Flight 901 that once it is 40 miles west of McMurdo station, it could be picked up by radar and guided down to an altitude of 1500ft. This suggestion was accepted by the aircrew.


Flight 901 reports itself to be 43 miles north with a cloud layer beneath. The aircrew ask for a descent in visual conditions expecting to find a gap in the clouds. The aircraft would be flying visually and without radar. Mac Centre approved its descent as it flew at 18000ft.
The Aircraft is at 10,000ft and requests a radar descent to 1500ft. Mac Centre accepts. There is cloud cover at altitude below the aircraft.
Flight 901 informs Mac Centre that it was under visual meterological conditions and would navigate visually to McMurdo - suggesting that the aircraft had found an area free of clouds to descend from. Mac Centre advises them to keep Mac Centre informed of their altitude and to let them know when they were 10 miles from McMurdo.
Flight 901 informs Mac Centre that it is at 6000ft descending to 2000ft in VMC. Mac Centre acknowledges and expects the aircraft to come into its visual view in a few minutes. Observers at the Ice Tower note that Mt Erebus was surrounded by cloud, whereas McMurdo sound was free from cloud. Observer may have been puzzled as to the reports of cloud from Flight 901.
The Ground Proximity warning alerts the aircrew of dangerous terrain. The flight crew immediately go to go around power and begin the ascent process. The flight data recorder shows they are unaware of the approaching mountain.
 12:49pm + 6 seconds
The aircraft collides with Mt Erebus and disintegrates. All 257 passengers and crew are killed in the sudden deceleration at impact.
Ice Tower does not see the aircraft in visual view and has not had any communication in 5 minutes. Radio operators at Ice Tower and Mac Centre begin radio calls to the aircraft and to nearby aircraft in an attempt to figure out where Flight 901 is. They are unsuccessful.
The aircraft has been silent for nearly an hour. Procedure requires the aircraft to communicate to Mac Centre atleast every 30 minutes. Mac Centre contacts Air NZ headquarters and advised that there has been no contact for an hour. Mac Centre advises Air NZ to place search and rescue on standby.
The US Military begins its search for Flight 901 after the lack of radio contact since 12:50pm. A starlifter and two helicopters begin searching McMurdo sound.
The US Military decide to expand their search are to include Ross Island due to a lack of progress at McMurdo sound where the aircraft was believed to have flown.
Air NZ CEO Morrie Davis officially declares that Flight 901 is lost, and that the aircraft would now have run out of fuel.
A black smear is discovered by a C-130 Hercules on the slopes of Mt Erebus, the aircrew ask for helicopters to take a close look.
 1:25am - 29 November 1979
An American Helicopter arrives at the scene, and formally identifies the wreckage as that of Flight 901, the helicopter does not land due to weather conditions. There are no survivors.