Video simulation images have emerged showing the final moments of the Aeroflot-Nord Boeing 737-500 that crashed in Perm, Russia, illustrating that the aircraft entered a steep left roll from which it did not recover.
The simulation - which appears to have been released by the Russian Interstate Aviation Committee (MAK), the investigators of the accident - clearly reveals the instability of the aircraft's flight path at the time.
While the simulation shows daylight conditions, the flight was actually operating in darkness and cloud during the early hours of 14 September last year.
MAK concluded that the 737's crew became disorientated while trying to prepare the jet for its landing approach, and identified poor training, problems interpreting the flight instruments and a lack of crew resource management as being partly responsible.
Russia's transport minister, Igor Levitin, has ordered an assessment of aviation training centres to check compliance with licensing requirements, in the wake of the accident which killed all 88 on board.