The resolution of conflicts between n aircraft is highly combinational and cannot be optimally solved using classical mathematical optimisation techniques. Using a priority order to solve a n-aircraft conflict is much easier but the solution is not optimal. However it is difficult to determine the best order, or even an order that is good enough to ensure that a solution exists. In this paper, a comparative study on a set of proposed heuristics to provide a suitable order is presented. Heuristics are tested on simulations using real traffic data.