Investigation Summary
The flight was part of a popular sightseeing program. Prior to departure, the navigation coordinates for the 'McMurdo' waypoint were changed by the airline's navigation section. The new coordinates shifted the flight path from a safe route over the flat sea ice of McMurdo Sound to a path directly over the 12,448-foot Mount Erebus. On the day of the flight, the crew, believing they were on the original safe path, descended below the cloud layer to provide passengers with a better view. Due to a phenomenon known as 'sector whiteout,' the white slopes of the volcano were indistinguishable from the surrounding ice and sky, preventing the crew from seeing the mountain until it was too late.
Final Conclusions
While the initial Chippindale Report blamed pilot error for descending below minimum altitudes, the subsequent Mahon Report placed the blame on the airline for changing the flight coordinates without briefing the crew. Justice Mahon famously described the airline's defense as 'an orchestrated litany of lies.'
Video Analysis
The Mount Erebus Disaster: Air New Zealand Flight 901 — An analysis of the navigation errors and atmospheric conditions that led to the DC-10 crash in Antarctica.
Watch on YouTube ↗If playback is blocked, the owner has disabled embedding — use the link above.
Systems & Failure Modes
AINS (Area Inertial Navigation System)
The computer system used to navigate the aircraft based on pre-programmed waypoints.
GPWS (Ground Proximity Warning System)
The system alerted the crew 6 seconds before impact, but the terrain was too steep for recovery.
Interesting Facts
- 01The navigation coordinates were changed the night before the flight.
- 02The crew was never informed that the waypoint had been moved 27 miles to the east.
- 03Sector whiteout conditions made the mountain invisible to the pilots despite clear air.
- 04All 257 people on board were killed instantly upon impact.
- 05The disaster remains New Zealand's deadliest peacetime event.
Safety Actions & Advisories
Navigation Data Verification
Strict protocols were established for verifying and communicating changes to flight management system (FMS) databases.
Whiteout Training
Enhanced training for pilots regarding the optical illusions and hazards of polar flying and sector whiteout.