Path planning is one of the most important tasks for mission definition and management of manned flight vehicles and it is crucial for Unmanned Aerial Vehicles (UAVs) that have autonomous flight capabilities. This task involves mission constraints, vehicle’s characteristics and mission environment that must be combined in order to comply with the mission requirements. Nevertheless, to implement an effective path planning strategy, a deep analysis of various contributing elements is needed. Mission tasks, required payload and surveillance systems drive the aircraft selection, but its characteristics strongly influence the path. As an example, quad-rotors have hovering capabilities. This feature permits to relax turning constraints on the path (which represents a crucial problem for fixed-wing vehicles). The type of mission defines the environment for planning actions, the path constraints (mountains, hills, valleys,…) and the required optimization process. The need for off-line or real-time re-planning may also substantially revise the path planning strategy for the selected type of missions. Finally, the computational performances of the Remote Control Station (RCS), where the mission management system is generally running, can influence the algorithm selection and design, as time constraints can be a serious operational issue.