A Multi-stage Centralized Approach to Formation Flight Routing and Assignment of Long-haul Airline Operations Topics: Air, Road, and Rail Traffic Management; Cognitive and Context-aware Intelligence; Cooperative Driving and Traffic Management; Engine-Efficiency and Emissions Control; Traffic management Reporting Systems In Proceedings of the 4th International Conference on Vehicle Technology and Intelligent Transport Systems VEHITS - Volume 1, 47-58, 2018 , Funchal, Madeira, Portugal