Air New Zealand Flight 901 was a scheduled sightseeing service from Auckland Airport in New Zealand to Antarctica and return with a scheduled stop at Christchurch Airport to refuel before returning to Auckland. The Air New Zealand flyover service, for the purposes of Antarctic sightseeing, was operated with McDonnell Douglas DC-10-30 aircraft and began in February 1977. The flight crashed into Mount Erebus on November 28, 1979, killing all 257 people on board. Passenger photographs taken seconds before the collision ruled out the flying in a cloud theory, showing perfectly clear visibility well beneath the cloud base, with landmarks to the left and to the right of the aircraft visible. The mountain directly ahead was lit by sunlight shining from directly behind the aircraft through the cloud deck above, resulting in a lack of shadows that made Mount Erebus effectively invisible against the overcast sky beyond in a classic whiteout (more accurately, flat-light) phenomenon. Further investigation of the crash showed an Air New Zealand navigational error and a cover-up that resulted in about $100 million in lawsuits. Air New Zealand discontinued its flyovers of Antarctica. Its final flight was on February 17, 1980. During the Antarctic summer, snow melt on the flanks of Mount Erebus continually reveals debris from the crash; it is visible from the air.