Mission planning can be considered from the point of view of artificial intelligence, control theory, formal methods and hybrid systems. An automated mission planning can enable a high level of autonomy for a variety of operating scenarios. The mission planning has to define a series of steps to define a flight plan. A strategic level regarding the choice of the way-points must be made before the operational decisions. These decisions are strongly related to factors such as UAV range and endurance, topography and communications and the mission requirements. The calculation of a flight plan involves the consideration of multiple elements. They can be classified as either continuous or discrete, and they can include non-linear aircraft structure and performance, atmospheric conditions, wind forecasts and operational constraints. Moreover, multiple flight phases can also be considered in flight planning [79]. Scheduling algorithms must be integrated into an embedded architecture to allow the system to adapt its behavior to its state and dynamic environments. The approach can reduce the uncertainty inherent in a dynamic environment through on-line re-planning and incorporation of tolerances in the planning process [57]. The motion plan is constrained by aircraft dynamics and environmental/operational constraints. In addition, the planned path must satisfy multiple, possibly conflicting objectives such as fuel efficiency and flight time. Integration in route optimization must take into account that the activation calculations plan is triggered by events.