During a flight, pilots must master complex situations, while facing increasing system complexity due to the amount and type of information available. As part of the Horizon 2020-funded programme of work, Clean Sky 2, Co2Team (Cognitive Collaboration for Teaming) pursues the idea that a system based on artificial intelligence can effectively support the pilot using cognitive computing towards single pilot operations. To create collaboration between the pilot and the intelligent agent, an innovative bi-directional communication paradigm and an intelligent allocation of roles and tasks are needed, based on the concept of keeping “pilot in the loop”. In this way it is possible to benefit and enhance the most effective skills of pilots, such as decision-making, to achieve flight objectives and guarantee a maximum level of safety and better acceptability. In our state of the art, we examine the different human factors identified in the literature that are involved in the integration of an intelligent agent for cockpit operations with all that this implies in terms of complexity.