The present work focuses on the development of a waypoint-based guidance algorithm to conduct an autonomous multicopter over a number of plants (grapevines, but application to other crops is worth investigating) in order to precisely administer plant protection products (PPP). The position of each plant requesting intervention is fed into the algorithm, which will generate a feasible path by means of a Traveling Salesman Problem (TSP) solver and a suitable path planning routine (Theta*). In the second part of the work, said path is provided to the UAS's autopilot (implemented in Simulink) for the execution of the task. Since the development of the spray controller is still underway, the need for a certain flexibility in the planning effort arose and therefore this work is intended as a framework to be expanded by further research..