In recent years, , newer and newer designs of unmanned air vehicles have been appeared and in a spread and spread area. That is why, their service and in particular their diagnostics should be carried out both before and in each flight. In this paper, a description of both unmanned air vehicle JET-2 and its units and control system are presented. The paper includes also description of signals which are transmitted in a real time from the dron to the flight control station. These signals enable to state whether the vehicle works in a correct way. An interactive diagnostics model is presented as two united equations of state which are based on an observation that the usable value of the UAV resulting from its working standards, depends on its technical condition and what is more, technical condition depends on its working condition (intensity of usage). It should be stated that technical conditions are an environment for working conditions and working conditions are an environments for technical conditions. Presented model gives a comprehensive information about technical and working capability of a vehicle. It enables to plan next flights taking into account their currant potential and capability.
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