The vision of SESAR is to integrate and implement new technologies to improve air traffic management (ATM) performance. Enhanced automation and new separation modes characterize the future concept of operations, where the role of the human operator will remain central by integrating more managing and decision-making functions. The expected changes represent challenges for the human actors in the aircraft and on ground and must be taken into account during the development phase. Integrating the human in the ATM system development starting from the early design phase is a key factor for future acceptability. This paper describes the adaptation of currently applied Cockpit Human Factors processes in order to be able to design the aircraft for the future ATM environment. Starting with the Airbus experience in successfully integrating Human Factors (HF) in the design and certification of aircraft, factors are described that identify how human actors can be integrated during the system engineering process when taking an air/ground perspective. For aircraft, the real added value of HF has been shown in being able to identify the real and relevant HF issues and to permanently adapt the methods to design and demonstrate efficient, easy to use, and safe aircraft. Building new technologies in aircraft for the future ATM requires not only to strive for a Human Factors Integration focusing on systems and Human-Machine Interfaces (HMI) but also integrating concepts of inter- and intra-organizational human cooperation on the level of an operational concept. Lessons learnt will be developed by combining principles of a human-centered approach and system engineering processes to support designing aircraft for a future ATM environment in a coherent and efficient manner. Examples such as 4D operations will be used to demonstrate facilitators or showstoppers for successful air/ground Human Factors integration from an aircraft manufacturer perspective.