How did it happen the plane crash on November 28 1979?

Answer 1

The crash of Air New Zealand flight 901, like many disasters, was the result of several factors.

1. Confusion regarding the chosen route The flights designated route had been adjusted prior to the flight without the flightcrew being notified.

2. Weather conditions. The flight was a sight-seeing flight, and in order to give passengers a view of the terrain, the flight crew had to fly below the 2000 to 3000 foot ceiling.

3. The aforementioned low ceiling caused a white-out visual illusion which prevented the pilots from seeing Mount Erebus.

4. The flightcrew, while experienced, had never flown in Antarctica before and were not familiar with the hazards antarctic flying can present.

A much more detailed description of the events can be found on the wikipedia, the corresponding page is linked below.