Mistakenly assuming their ground speed to be faster than it really was, the crew may have deduced that they had already safely crossed the Andes, and so commenced their descent to Santiago, whereas in fact they were still a considerable distance to the east-north-east and were approaching the cloud-shrouded Tupungato Glacier at high speed. Some BSAA pilots, however, have expressed scepticism at this theory; convinced that Cook would not have started his descent without a positive indication that he had crossed the mountains, they have suggested that strong winds may have brought down the craft in some other way. One of the pilots recalled that we had all been warned not to enter cloud over the mountains as the turbulence and icing posed too great a threat.