In the scope of assessing the impact of the delegation of crossing operations to the flight crew, an experiment with twelve controllers from different European countries has been carried out. The airspace simulated was a part of the Paris area, and consisted of two measured sectors with varied conflict situations. The controllers' feedback is positive: delegation would allow solutions to be selected sooner, would induce less time-critical instructions and therefore would provide them with a higher availability. However, controllers questioned the usability in heavy traffic conditions, e.g. with more complex situations. The quantitative objective measurements match the subjective feedback from the controllers in suggesting potential benefits from delegation in en-route. A reduction of the number of manoeuvring instructions has been measured. The analysis of the distribution of manoeuvring instructions shows that the instructions are given earlier. No significant impact in terms of flight efficiency was observed, although for the crossing point considered trajectories become straighter. At this point, no significant impact on safety was observed.