As the Unmanned Aerial System (UAS) Level Of Automation increases, Mission Planning relevance raises. A mission plan can be defined as all the information needed to reach the assigned goals, and it is composed by several sub-plans. In particular, the mission plan core is represented by the routes. Since the route creation process is very complex, the introduction of route creation and verification algorithms is required. These algorithms enhance also the crew replan performances during the mission execution, and permit to implement autonomous onboard replanning. Furthermore, Planning/replanning processes could also have a key role in the integration of UAS in the civil airspace. According to these considerations, a Mission Planner embedded in the Alenia Aermacchi UAS Ground Control Station has been developed, comprised of advanced planning algorithms. kts Knots LAT Latitude LOA Level Of Automation LON Longitude LOS Line Of Sight MALE Medium Altitude Long Endurance NAS National Airspace System NAVAID Navigational Aids RF Radial to Fix RTI Run Time Input SAR Synthetic Aperture Radar SATCOM Satellite Communications SESAR Single European Sky ATM Research