In the interests of improving the quality of uncrewed aerial vehicles (UAV) group flight planning, the formulation of the problem of developing algorithms for the operational determination of the admissible monitoring and the required number of UAV when servicing the flow of applications, taking into account the impact of loss of efficiency, is formulated. The purpose of the work is to develop algorithms for planning a group flight, taking into account the priority of the object of observation, its remoteness and the flight time of the group. The novelty of the work is the proposed approach to solving the problem of pre-flight planning of UAV group flight. The approach consists in performing a procedure for calculating the rational number of UAVs for erforming flights in a given territory, followed by clustering all objects of interest to exclude intersections of their routes and implementing the developed modified genetic algorithm. At the same time, the modification of the known genetic algorithm consists in the formation of the initial "elite" of routes using two special criteria that take into account the priorities of the objects of observation, their distance from the UAV group, and the time to complete the flight task.