Hate to let you all know but many of these "speculations" are incorrect. Being the other pilot in the other aicraft and being there the day of departure I can let you all know there is no way the tank shifted aft it simply was not possible, there was light weight suitcases 2 of them put against the back wall stopping this from happening.
Going to the site it was clearly an engine failure! it is unfortuneate and extremely sad that the outcome was as such but I assure you all he done everything in his power to put it down safely but obiously there were other factors of which none of us will ever really know all I know is he was a very competent pilot.
