Air traffic demand is expected to increase, while the system is already working at its limits. New decision support tools with higher levels of automation that allow for four- dimensional (4D, i.e., space and time) trajectory-based operations are proposed to cope with the increase in traffic demand. This research presents a conceptual interface that allows for flow-based perturbation management in air traffic, based on the principles of Ecological Interface Design and by means of influencing a trajectory planning algorithm. A first evaluation of this interface, in which five participants were asked to structure a perturbed airspace as they saw fit, showed that the participants were able to influence the algorithm as they wanted in most cases and were supported by the ecological interface that visualized the workings of the algorithm. However, human influence predominantly did not improve the solution in terms of robustness and efficiency. Improvements to the interface are suggested and its use case needs further research. ... Read more