Many safety advancements in aviation have been achieved, through improvements in aircraft systems technology and automation. In contrast, these same factors have been pointed as contributing factors in some aviation accidents. The increasing automation and complexity in aircraft systems may present considerable challenge to flight crews all over the world and concerns related to human machine interface appears. In an unexpected or non-normal event, mainly in high work-load circumstances, it is not uncommon to emerge problems in decision-making related to interaction with complex aircraft systems, such as loss of situational awareness, over-reliance, lack of vigilance, misprogramming, which may be affected by human performance variability into a stressful situation and potentially lead to an accident. This paper proposes use the Functional Resonance Analysis Method (FRAM) as a valuable tool in supporting safety analysis in sociotechnical systems to reconstruct an event scenario to bring clear comprehension in the everyday performance adjustments and to allow characterize the main points where the variability of human performance, in a given specific situation, could lead to an observed negative result. In this way, the main points could be monitored and damped aiming to anticipate and prevent future occurrences. In addition, this paper also proposes the application of the Perceptual Cycle Model (PCM) in the analysis of naturalistic decision-making coupled to the FRAM model.