This paper presents the initial evaluation of the EACAC study, which is investigating delegation by the controller to the pilot of some tasks related to separation assurance. The concept is applied in managed airspace for two classes of application: crossing and passing in enroute, and sequencing in Terminal Manoeuvring Area. The concept relies on two key points discussed in the paper: “limited delegation” and “flexible use of delegation”. The initial evaluation using a simplified ATC environment has been set up to get “feedback” from both controllers and pilots, and to assess the operational feasibility and potential interest of the concept. The overall feeling about the method is “promising” with a “great potential”, and could reduce workload. The notion of “flexible use of delegation” would enable the gradual growth of confidence and would also provide flexibility to use the method under different conditions (traffic, airspace, practice level). It has been highlighted and observed however that the conditions of applicability of the method must be respected, otherwise it could worsen the situations, resulting in an increase of workload and communication. The next step of the study will therefore be a “quantitative” experiment with the objective of evaluating expected gains of the method.