Designing a Control Simulator involves many difficult problems: modeling conflict detection, trajectory uncertainties, solving conflict inside sectors, respecting military areas constraints, coordinating aircraft between sectors, etc\ldots Moreover, the n-aircraft conflict resolution problem is highly combinatorial and cannot be optimally solved using classical mathematical optimization techniques. The set of admissible solutions is made of many unconnected subsets enclosing different local optima, but the subset enclosing the optimum cannot be found a priori. In this paper, we present a conflict solver and its implementation in an Air Traffic simulator, with statistical results on real traffic in a French Sector. This solver, which takes into account real flight plans, solves every conflict inside a sector or over the French airspace on a loaded day.