Reliability degradation, preventive and corrective maintenance of UAV systems

In this paper we examine the problem of the preventive and corrective maintenance of UAVs systems taking into account the specific needs of the unmanned machine (and therefore completely different from the needs of a normal airplane) to define the optimal maintenance interval. In the first part, we compare the issues of the maintenance philosophy for UAVs and develop problems related to the degradation of the performance of unmanned aircraft. In the second part, we examine the problem in an analytical way: in the probabilistic computation, we will insert the concepts of preventive and corrective maintenance that consider the degradation of the system. The system itself is understood as composed of a number of subsystems also their subjects (before the real 'hard failure') to partial performance degradation ('soft failure').