The article analyzes the meaning of the term "equivalent flight safety". The need for such an analysis is due to the fact that there is no definition of this term in the guidance documents on engineering and aerodrome flight support. This creates the ambiguous interpretation of the meaning embedded in this term and the possibility of non-compliance with the necessary flight safety measures at the aerodrome. As a result of the analysis, the expediency of the use of the term "equivalent level of flight safety" when determining the aerodrome operational suitability is substantiated. Management of the state of the aviation system from the point of view of information theory is considered. As a result, it was established that the ability to assess the impact of each element of the aviation system on its security against the effects of hazardous factors makes it possible to increase the efficiency of managing the state of this security. Dependence of the aerodrome flight safety level on the legality of the aerodrome operation is shown. The feasibility of achieving the equivalent level of flight safety using a new indicator, the equivalence coefficient, is substantiated. The formula that allows to calculate this indicator is derived. The numerical value of the equivalence coefficient depends on the values of the coefficients of compliance with the aerodromes operational suitability standards. The minimal set of evaluated elements is shown which determines the value of each coefficient of compliance with the aerodromes operational suitability standards. A mathematical model that reflects the dependence of the coefficient of compliance value with the operational suitability standards on the estimated indicators is constructed. The coefficients and indicators considered in the article in aggregate represent a new approach to assessing the level of aerodrome flight safety. This approach can be successfully applied in assessing the level of flight safety by any element of the aviation system.

The article based on the method of statistical frequency stabilization deals with the issues of increasing frequency stability and synchronization of the forming HF signals in a transmitting device of a localizer using a multichannel variant of construction. It was demonstrated that the available digital unit of frequency and phase correction allows easy application of the proposed method. Two main features of the localizer operation affecting frequency stability and phase synchronization of HF signals are noted. The first factor is determined by deviation of the present -HF signal frequency (on the measurement interval) from the average ⁽ⁱ⁾ frequency value in n-channel. The second one is related to average frequency variation of each of the forming HF signals and its deviation within the ⁽ⁱ⁾ value from the nominal value during localizer operation. On the basis of HF signals description in channels of the transmitting device of a localizer ratios are obtained determining optimal values in terms of the method of least square method as ⁽ⁱ⁾ deviations of the present frequency values from the average value as well as variations of average frequency values during localizer operation. The article considers the most significant, from an applicatory point of view, case of assessment covering only deviations of the present HF signals frequency values from the average value on the measurement interval. It is shown that application of the method of statistical frequency stabilization allows the transmitting device of a localizer including N channels of HF signals formation to increase frequency stability and HF signals phase synchronization times. That enables to improve accuracy of forming integrated and difference directivity diagrams and setting heading in the runway direction as well. Apart from that, on the basis of the received values of frequency parameters estimation and relative instability of the forming HF signals a decision can be made about the condition of the controlled parameter by the criterion STANDARD-DETERIORATION-ACCIDENT.

The problem of foreign-made spare parts and components import delivery is relevant because international cooperation in aviation industry has become widespread. Logistics provides not only new components procurement but also borrowing, renting, leasing or exchange operations. To control the process effectively, it is necessary to decompose the import delivery process, as effective integrated logistics provides spare parts and components delivery within the shortest time and the lowest costs. Project management methods are used for this purpose. The object of the research is import delivery of foreign-made spare parts and components to maintenance and repair center. For the shortest delivery time and the lowest delivery costs it is necessary to describe the import delivery structure, to determine the import delivery works interrelations and their duration and to standardize implementation costs. The research describes the foreign-made spare parts and components import delivery structure, explains the operations sequence, sets the approximate work duration. The import delivery network schedule was also made. Implementation of the resulting structure in project management software will allow to control import delivery time and costs, to make out reports on resource usage. The import delivery project passport will help to manage the resources costs, used for spare parts and components delivery as well as to optimize the project.

The construction and useful practice of gas-turbine engine diagnosis systems depend largely on the availability of the engine mathematical models and its certain components in their structure. Utilization of multi-stage axial flow compressor performance with account for erosive wear of its parts during the operation fundamentally raises possibilities of such systems as erosive wear of flow channel, blade rings of impellers and vane rings of multi-stage compressor is a common cause of preschedule gas-turbine engine detaching from an aircraft. As evidenced by various contributions presented in the article, special emphasis on abrasive wear impact assessment on axial flow compressor performance is placed upon rotor-wing turbo-shaft engine due to their particular operating conditions. One of the main tasks in the process of mathematic simulation of an axial flow compressor blade ring is consideration of its wear type that again has a nonlinear distribution along the level of the blade. In addition, wear rate at entry and exit blade edges often have different principles. Detecting of these principles and their consideration when constructing the compressor mathematical model is a crucial task in diagnostic assessment and integrity monitoring of rotor-wing turbo-shaft engine in operation. The article represents a concept to an estimate nonlinear erosive wear effect of axial flow compressor blades on its performance based on the three-dimensional flow approach in the gas-air flow duct of compressor with a formulation of the blade rings. This approach renders possible to take into account the nonlinearity of the compressor blades wear during their operation. Through the example of the inlet compressor stage of a rotor-wing aircraft gas-turbine engine, the engine pump properties predictions with different kind of rotor blade wear have been presented.

In modern conditions of limited budget for enterprises of aerodrome operators, the task of optimizing decision making in flight safety management is becoming extremely urgent. Management decisions, which are a safety management tool, must be not only effective in terms of expected improvements in safety, but also cost-effective and appropriate for the enterprise. Optimization in this article should be understood in terms of the mentioned criteria. The article presents a method for supporting management decision-making as part of a safety management strategy for the activities of aerodrome operators. In the presented methodology, an important place is given to indicators of the level of safety of flights and their use in making managerial decisions. Along with the safety indicator, an indicator of financial damage from recorded events is used, which is calculated in value terms taking into account direct and indirect damage to the aerodrome operator. Regression modeling is used in conjunction with the decision-making technique of “human-machine procedures”. Regression analysis is performed using STATISTICA software, and allows you to identify the dependence of indicators on the degree of influence of hazard factors. The resulting model, based on data from last year, makes it possible to forecast the values of indicators for the next. Using the decision-making methodology of “human-machine procedures”, an assessment is made of the priority of implementing managerial decisions based on an integrated criterion. The methodology ensures compliance with the requirements of Russian and international air legislation for operators of certified aerodromes. The scope of its application can be expanded to SMS of all aviation service providers, taking into account the relevant specifics of the services provided and the existing hazard factors.

On the basis of the study of air flight control, as well as the need to take into account the regional parameters of the airspace, the expediency and the need for mathematical modeling of the air navigation environment were identified. The article deals with the features of the model of air navigation environment, in which the base of the study adopted the basic information used to describe the plan for the execution of air flight. In the study, it was found that in navigation main feature is the geodesic of abstraction, however, such information was found, is not complete for the plan for air flight. The study emphasized the role of taking into account all the restrictions by which certain prohibitions on the use of specific volumes of airspace are imposed. Based on the results obtained, a graph of the geometric representation of the airspace with constraints was constructed. The results of the study allow us to conclude that the construction of a mathematical model of the air navigation environment allows us to achieve the following results: optimization of the distribution of the EAP loads by sectors, visualization of the air navigation situation in the region, the establishment of critical load directions, the collection of data on the load, the study of the factor effects on the regularity and safety of the aircraft movement. The mathematical model of the aeronautical situation was built with the help of a composition of hierarchical type. As a result of such construction of mathematical model its transformation with addition of new models is possible. Using the proposed mathematical model in the framework of discrete event systems can be used to simulate complex air navigation environment with a large number of aircraft. The use of the formalism presented in this study allows a clear distinction between the mechanism of information processing and the information itself in the process of modeling.

Projects and experimental models of innovative concepts of VTOL aircraft with a hybrid propulsion system are attracting great interest and investment inflow all over the world. In this regard, when developing new concepts, it is important to understand how much better they will be than the currently operated rotorcraft and convertible aircraft in terms of reliability and flight safety, to be able to use them for passenger transportation in the future. In addition, when designing and choosing the optimal layout, it is necessary to know the contribution of each element and unit to the reliability of the aircraft as a whole in order to meet the requirements. To calculate the reliability indicators, the method of structural diagrams was chosen, and the calculation methodology was developed. The general classification of modern innovative concepts of convertible aircraft is considered, schematic diagram of hybrid propulsion system and its main parameters are determined. The article discusses the influence of the number of lifting rotor groups and their location on the possibility to continue the flight in hover mode in case of failure of one rotor group, the necessary power reserve of lifting electric motors is determined to ensure the given safety condition. In accordance with the adopted structural diagram, the main functional groups of the hybrid propulsion system of convertible aircraft operating in different flight modes are determined. The basic modes of a typical flight profile of a convertible aircraft are considered, time intervals characteristic for each mode are set. For each flight mode, a structural scheme of reliability of functional groups of a hybrid propulsion system is constructed, having a serial or parallel connection of elements, depending on their influence on the consequences of failure, the equation for calculating the probability of fail-free operation is derived. For lifting rotor groups, a combination of critical failures of more than one group is considered, and the equation is composed to calculate the probability of a catastrophic event in hover mode. Based on the obtained equations, the resulting calculation of the probability of fail-free operation, the probability of failure per flight hour for each flight mode was carried out separately and in total for the entire flight. Thus, for all flight modes, the probabilities of a catastrophic and emergency event, as well as a difficult situation in flight, are considered. A comprehensive analysis of the obtained results of reliability indicators calculation for convertible aircraft with six lifting rotors and two turboprop engines made it possible to conclude that it meets the requirements of the 25th part of aviation regulations for transport aircraft. A good potential margin of up to 10-2 was determined for the probability of a catastrophic failure in take-off, landing and transitional modes. The elements and subsystems that are critical for fail-free operation are identified, and ways to improve their reliability and the aircraft as a whole are proposed.