Description: In the article were considered methodological foundations for ensuring of the functional stability of aircraft flight and navigation complex. They include a set of scientific methods and mathematical models, approaches and mechanisms to solve the above-mentioned scientific problem. The basis for ensuring of the functional stability of aircraft flight and navigation complex in the article are procedures for maintaining of the separate modules knowledge bases of the distributed system in the valid condition which is solved through the organization of the dynamic verification of such knowledge bases during their application. The diagnosis of aircraft flight and navigation complex refusal according to the method proposed in the article is based on the principle of probabilistic diagnostic core, which includes: performing tests in flight and navigation complex system, which takes into account the random structure of diagnostic connections, the accumulation of diagnostic information in the memory of flight and navigation complex elements, the determination of the sufficiency of diagnostic information for performing its analysis, decoding of diagnostic information to determine the condition of the flight and navigation complex information modules. Based on the verification of the flight and navigation complex information modules a recovery management is formed and, based on the conditions for satisfying the main task of the flight and navigation complex, the probability of performing the full target during the flight on the route or at other flight modes is determined. To solve the problem of ensuring the steady functioning of the aircraft navigation aids system in the conditions of perturbed space weather, a general complex model of the functioning of satellite navigation system (SNS) under the influence of destabilizing heliogeophysical perturbations is considered. The main mechanisms of functional stability of aircraft navigation means in conditions of destructive influence on them of perturbed space weather are defined.
Keywords: flight and navigation complex, destabilizing factors, functional stability