Improving of the aircraft continued airworthiness system is currently becoming of particular importance applied both to aircraft of domestic and foreign production, used in civil aviation of Russia. This article discusses the background and content of the tasks for long-haul aircraft continued airworthiness, which presents a challenge directly related to the provision of intensive, regular, economically viable, and safe operation of assigned airline fleet. A special place among the problems of continued airworthiness is held by the creation and organization of mechanisms and methods of resource status and age of the assigned airline fleet monitoring to manage its forecasting and timely updates. Not least important among the issues of resource and age structure monitoring to be considered is the need to improve the design of aircraft, taking into account preliminary technical and economic feasibility assessment of its modifications in the interests of the operator. A deep study of the contents of the monitoring allows to develop up-to-date methodological and scientific basis for building an integrated system of aircraft resource management and timing services. This system is developed based on the integrated approach that allows to provide a solution to the entire set of problems presented in this article and faced by professionals and scientists involved in the aircraft maintenance programs development on the stages of their design and manufacturing and long operation of aircraft continued airworthiness.

Avionics Technical Operation System (ATOS) is a set of objects and subjects of technical operation such as avionics itself as an object, personnel, carrying out procedures and organizing technical operation processes, as a subject, hardware and software for technical operation and maintenance and repair programs as well. ATOS is subordinated to Aircraft Technical Operation System (A/C TOS), which determines its goal and restrictions. The quality of ATOS is characterized by a set of properties that determine its ability to meet the maximum economic efficiency of the needs of A/C TOS, while ensuring the required levels of avionics reliability and availability. Avionics Maintenance System, Avionics Repair System and Avionics Operation Test System are the systems of a lower level of hierarchy in relation to ATOS, which defines the goals and restrictions of these subsystems. Based on the analysis of ATOS as an object of research, analysis of mathematical modeling as a research apparatus and the developed hierarchy of efficiency criteria for ATOS and the systems interacting with it, we formulate the overall task of the research as follows. On the set of parameters of ATOS, we have to find such parameter values that the system costs in process of technical operation reach the minimum when all the required tasks are fulfilled and all the restrictions on the system own parameters and indicators of its technical efficiency are met. To solve the general task it is necessary to solve successfully a lot of tasks, formulated in this article. The theoretical results obtained during the research can serve as a scientific basis for solving practical problems of the formation and improvement of ATOS. Formation and improvement of ATOS is a long and laborious process, requiring the usage of the most advanced mathematical methods. Thus, mathematical modeling of ATOS should significantly reduce the costs of the system's formation, since it allows us to introduce certain adjustments in the early stages of its operation on the basis of available and constantly updated information.

The article deals with the civil aviation industry educational cluster which consists of the civil aviation educational establishments of the Russian Federation, comprising structural divisions (constituents) that provide specialist training for both higher and secondary vocational educational programs. Innovative requirements for aircraft maintenance specialist training challenge for a complex of modernization measures intended to provide educational system compliance with the needs of the aviation enterprises. In order to formulate the mentioned measures, the research separates basic structural components of the educational cluster, which change within the modernization process under the influence of the external environment. The article suggests the hierarchical model of the educational cluster modernization process management. Basing on the expert monitoring assessment principles, the educational establishment structural-functional model representing the hierarchical relations of the industry educational cluster objects is developed. Considering that these relations elements interact ambiguously which results in the system properties uncertainty, the research demonstrates the need to create an algorithm for the educational system integral quality assessment system. On the grounds of integral assessment comparative analyses for both the functioning and modernization modes, the work suggests the decision-making mechanism for the measures to be taken. A conclusion is made that the model-based approach allows to choose the best option among the modernization measures (synchronized with the current functioning and at the same time providing civil aviation educational cluster innovative development) step-by-step for a certain calendar period.

The paper presents the authors’ view on one of the most important issues of civil aviation under current conditions – ensuring aviation security of civil aviation objects. The authors understand "aviation security" in terms of the definition given in the Air Laws and Regulations. The authors consider it possible to speak and use nothing but the term "aviation security" since the term "transport security", introduced relatively recently, does not fundamentally contradict the term "aviation security" insofar as it concerns civil aviation. An original approach of the authors to the functional-essential understanding of air transport security is proposed. The approach is based on the analysis of sufficiently new security-related terms that have not been used so far in air transport security studies. It is bodily security, common security and indivisible security. As a result of the implemented study, the authors propose a new term: integral air transport security. Besides, the authors give the definition of integral security term, structure the term and provide an analysis of the functional relationships of the structure elements. The statement of the issue of modeling the security (danger) of the object in the format of a hypothetical field that represents some state of the environment as a security space is presented. It is shown that the methodology of the study of integrated security is reduced to assessing security level and deciding the issue of its acceptability. For this reason, it is necessary to solve the issues of formalization and modeling. The authors believe that the mathematical apparatus of the theory of boundary value problems,  that are described by a system of partial differential equations, is the most adequate for formalization out of the many methods that field theory offers.

Currently, special attention is paid to the aircraft fuel quality as a component of safety to ensure trouble-free operation of the fuel system. The existing system of quality control involves periodic sampling of the fuel in the container and their subsequent control by the normalized quality indicators that do not identify possible reasons for the deterioration of these indicators to remove them for trouble-free operation and do not identify the factors of pollution sources. The monitoring system generally ensures the implementation of measures to preserve the quality of aviation fuel and flight safety of serviced civil aviation airlines at current level according to regulatory requirements. The article describes the mathematical model for calculation parameters of indicator filtering partitions based on cascade filtration theoretical studies of mechanical impurities. Pores of indicator filtering partitions calculated by means of mathematical model have been experimentally tested on simulator stand and showed a good convergence of calculated and experimental results. The use of cascade filtration of fuel with different indicator partitions parameters made it possible to develop a device for fuel purity monitoring, allowing continuous (inline) monitoring the level of liquid flow contamination at various points of technological equipment (for example, after the pump, at the inlet and outlet of tanks and units, the output of the filter, etc.) and to carry out functional diagnostics of units condition process equipment by monitoring changes of particle parameters and the wear occurrence.

The research determines the problems of pilot studies to assess the adequacy of the results of simulation in simulators operators of radio electronic equipment for air traffic control. Hardware requirements to conduct flight experiments to assess the adequacy of training facilities by members of the flight management group for air traffic control in the near field zone are formulated. For the probabilistic assessment of simulation adequacy in training facility radio electronic means (REM) operators the generalized criterion "Fisher - Chi-square" is selected, which allows to obtain the updated value of the significance level using the Fisher criterion, and based on this, using the goodness of fit Chi-square to produce a quantitative assessment of the adequacy of the simulation in the training facility radio electronic equipment. In order to improve the quality of training of the trainees (members of the flight management group) and a greater degree of approximation of processes that are modeled in training facilities at the ATC in the near field zone to the real conditions, the research proposes a method to evaluate the adequacy of the simulation results in training equipment operators REM ATC on the basis of the flight experiment. It is shown that when implemented on the basis of the flight experiment of the proposed method of assessing the adequacy of the equipment operators REM ATC, the reliable values of accuracy can be obtained simultaneously for ground and in-flight tracking of air objects that are used in their simulation models in training facilities for the traffic controllers training procedures. Experimental assessment of the air traffic control equipment operators adequacy allows the authors to come to the conclusion that the results obtained on the basis of the Fisher-χ2 and on the basis of the generalized distribution law can be used to form areas of implementation of means of conflict-resistant automated control system for RES operators training management.

Flight operations with the use of standards Reduced Vertical Separation Minimum (RVSM); Performance-based Navigation (PBN); auto landings on CATII CATIII ICAO categories have become common practices in relation to the relevant requirements of ICAO. In this case, operators should receive special operational permits, due to that the task of determining the feasibility of such operations became operational. Increasing the reliability requirements to estimate the accuracy characteristics quality of flight operations requires the development and improvement of methods for their evaluation. First of all, the application of methods based on more accurate representations of error models with more correct models of the error probability density distribution is required, especially in the field of large, rare errors. This article solves one of the tasks of this complex approach to estimate the accuracy characteristics – the task of processing flight information in order to determine the estimates of the accuracy characteristics of the flight-navigation complex (FNC), since the problem solving provides the possibility of obtaining an integral estimate of the accuracy characteristics based on the application of combined methods. It is shown that the power of the Nikulin criterion is almost twice as high as the Pearson power criterion, which in some cases excludes the acceptance of incorrect hypotheses about the form of the hypothetical distribution function. The use of Nikulin criterion makes it possible to significantly improve the assessments accuracy of flight quality performance characteristics according to RVSM, PBN, CATII and CATIII standards by increasing the criterion power. It significantly increases the estimates accuracy of the accuracy characteristics obtained during the deciphering of flight information.

Much attention is payed to the tasks for ensuring domestic and international aircraft safety and regularity, which are multifaceted and complex. One of them is the system of ensuring the quality of aviation fuel for refueling aircraft at airports. A significant influence of the quality, chemical composition and fuel range on the reliability and lifetime of components and parts of the aircraft fuel system was studied in the process of development and experience accumulation of aircraft operating, processes of aviation fuel production, as well as during storage, quality control, transportation, refueling preparation and aircraft refueling. Currently, work is being done to study the influence of fuel quality on the units of the technological scheme of fuel-filling complexes, which provide the required cleanliness of the fuel according to the regulations. The article describes the trend level of aviation fuel cleanliness at the stages from receipt to issuance to the refueling station. The evaluation of compliance with existing regulations on the level of jet fuel cleanliness and the efficiency of fuel cleaning facilities is carried out. It is stated that one of the problems of insufficient level of aviation fuel cleaning quality is a violation of the acceptable contamination level of the fuel before the filter. It was found that the disadvantage of the used filter paper is the fiber wash out process. According to this research it was found that while cleaning fuel from mechanical admixtures it is necessary to take into account the technical condition of the filtering element, and proposal was developed for fuel-filling systems to ensure aviation fuel cleanliness in compliance with regulations.

Dispatch reliability – is one of the key criteria of aircraft technical operation process efficiency which reflects economic efficiency of airline activity. The higher the operational reliability, the better the level of aircraft operation in airline, the higher maintenance quality and safety policy is more effective. Due to the lack of unified procedure of dispatch reliability control both for aircraft manufacturers and Russian Federation aircraft operators and based on international experience it was concluded that there is a need for dispatch reliability specification by introducing a number of parameters, definitions and development, thereby the unified updated methodic of calculation. In this work six basic and three auxiliary parameters are introduced, the following terms and definitions are established: dispatch reliability, operational reliability, ground operational interruptions, operational interruptions, in-flight  interruptions. A unified actualized methodic of dispatch reliability and operational reliability calculation is developed, which is reasonable and more accurate. Since the aircraft dispatch reliability includes the notion of Regularity and Punctuality, definitions and criteria calculation are given.  The detailed example of criteria calculation is shown: dispatch reliability, dispatch regularity, flight punctuality, operational reliability, flight delays for a hundred landings, aircraft changes for a hundred landings, flight cancellations for a hundred landings.

The avionics concept of the maintenance-free on-board equipment implies the absence of necessity to maintain onboard systems between scheduled maintenance, preserving the required operational and technical characteristics; it should be achieved by automatic diagnosis of the technical condition and the application of active means of ensuring a failsafe design, allowing to change the structure of the system to maintain its functions in case of failure. It is supposed that such equipment will reduce substantially and in the limit eliminate traditional maintenance of aircraft between scheduled maintenance, ensuring maximum readiness for use, along with improving safety. The paper proposes a methodology for evaluating the efficiency of maintenance-free between scheduled maintenance aircraft system with homogeneous redundancy. The excessive redundant elements allow the system to accumulate failures which are repaired during the routine maintenance. If the number of failures of any reserve is approaching a critical value, the recovery of the on-board system (elimination of all failures) is carried out between scheduled maintenance by conducting rescue and recovery operations. It is believed that service work leads to the elimination of all failures and completely updates the on-board system. The process of system operational status changes is described with the discrete-continuous model in the flight time. The average losses in the sorties and the average cost of operation are used as integrated efficiency indicators of system operation. For example, the evaluation of the operation efficiency of formalized on-board system with homogeneous redundancy demonstrates the efficiency of the proposed methodology and the possibility of its use while analyzing the efficiency of the maintenance-free operation equipment between scheduled periods. As well as a comparative analysis of maintenance-free operation efficiency of the on-board system with excessive redundancy and on-board system with rational redundancy serviced by the strategy of "to failure" is carried out.

A special aspect of aircraft test is carrying out both flight evaluation and ground operation evaluation in a structure of flying aids and special tools equipment. The specific of flight and sea tests involve metering in offshore zone, which excludes the possibility of fixed geodetically related measuring tools. In this regard, the specific role is acquired by shipbased measurement systems, in particular the mobile modular measuring systems. Information processed in the mobile modular measurement systems is a critical resource having a high level of confidentiality. When carrying out their functions, it should be implemented a proper information control of the mobile modular measurement systems to ensure their protection from the risk of data leakage, modification or loss, i.e. to ensure a certain level of information security. Due to the specific of their application it is difficult to solve the problems of information security in such complexes. The intruder model, the threat model, the security requirements generated for fixed informatization objects are not applicable to mobile systems. It was concluded that the advanced mobile modular measuring systems designed for flight experiments monitoring and control should be created due to necessary information protection measures and means. The article contains a diagram of security requirements formation, starting with the data envelopment analysis and ending with the practical implementation. The information security probabilistic model applied to mobile modular measurement systems is developed. The list of current security threats based on the environment and specific of the mobile measurement system functioning is examined. The probabilistic model of the information security evaluation is given. The problems of vulnerabilities transformation of designed information system into the security targets with the subsequent formation of the functional and trust requirements list are examined.

The current state of airborne measuring-and-computing complexes (MCCs) is characterized by the inclusion of distributed strapdown inertial navigation systems (SINSs) as components of these complexes. This is associated with the necessity of the provision of navigational support not only for aircraft (Acft), but also for airborne Earth surface surveillance systems in which the SINSs are included as components. Among such systems are radar systems, video monitors, laser scanners (lidars), and other surveillance devices. At the same time, when the DSINSs are united into a single structure, new functional possibilities for such integrated navigation systems appear, namely: redundancy and mutual support of SINSs, and also an increase in MCC information reliability on this basis; mutual monitoring and mutual diagnosis of SINSs; optimization of DSINS structure for providing the required accuracy of navigation and attitude control under severe conditions of Acft operation. Such conditions are connected with Acft maneuvering, with a loss of the signals of satellite navigation systems (SNSs). The purpose of this paper is to study the capabilities of DSINS which are built around fiberoptic and micromechanical sensors when they are united into a closely connected information-measuring structure. In the solution of the problem formulated above, an object-oriented modular technology for the creation of integrated navigation systems was taken as a basis. The use of such a technology has permitted us to realize the new functional possibilities of the DSINSs, and also to take into account the following features of the construction and functioning of DSINSs as components of MCCs: need for mutual information exchange among DSINS modules via an MCC airborne top-level computing system; synchronization of measuring-and-computing procedures that are realized in the DSINS. In addition, due to restrictions on overall dimensions and weight, SINSs of surveillance systems are built on the basis of microelectromechanical sensors (MEMSs). Such sensors have a wide insensitivity zone and low accuracy. Taking into account the above-mentioned features, SINS-MEMSs must rely on a base high-accuracy SINS which forms part of an Acft navigation complex. Moreover, the SINS-MEMSs cannot execute the initial alignment from attitude angles in the autonomous mode. Because of this, the initial alignment of such SINSs is realized from information obtained from the base system. Mutual support of integrated inertial systems which include satellite receivers is necessary not only for continuous updating of SINS-MEMSs coordinates but also for the refinement of attitude angles of the places where surveillance systems are mounted. It should be noted that the frequency of updating the coordinates that are determined by an SNS is several units of hertz, and that are determined by a SINS is several units of kilohertz. The features mentioned earlier were taken into account in a DSINS developed by the NaukaSoft Experimental Laboratory, Ltd. (Moscow) and by the Bauman Moscow State Technical University in cooperation. A breadboard model of the MSINS includes the SINS-500NS system based on fiber-optic gyros developed jointly by the “NaukaSoft EMNS” and by the “Optolink” RPC (Zelenograd); micromechanical SINS-MEMSs built on the basis of the ADIS16488 measuring modules developed by the Analog Devices Co. The paper presents the results of fullscale experiments performed at the Ramenskoye Instrument-Making Plant.

One of the important problems of the designing of maneuverable unmanned aerial vehicles (UAV) is to ensure aeroelastic stability with automatic control system (ACS). One of the possible types of aeroelastic instability of UAV with ACS is loss of stability in the system "surface control – actuator".  A nonlinear model for the study of the stability of the system "surface control – actuator" is designed for solving problems of joint design of airframe and ACS with the requirements of aeroelasticity. The electric actuator is currently the most widely used on highly maneuverable UAV. The wide bandwidth and the availability of frequency characteristic lifts are typical for the modern electric actuator. This exacerbates the problem of providing aeroelastic stability of the UAV with ACS, including the problem of ensuring the stability of the system "surface control – actuator". In proposed model the surface control, performing bending-torsion oscillations in aerodynamic flow, in fact, is the loading for the actuator. Experimental frequency characteristics of the isolated actuator, obtained for different levels of the control signal, are used for the mathematical description of the actuator, then, as dynamic hinge moment, which is determined by aeroelastic vibrations of the surface control in the air flow, is calculated. Investigation of the stability of the system "surface control – actuator" is carried out by frequency method using frequency characteristics of the open-loop system. The undeniable advantage of the proposed model is the simplicity of obtaining the transfer functions of the isolated actuator. The experiment by its definition is a standard method of determining frequency characteristics of the actuator in contrast to time-consuming experiments for determining the dynamic stiffness of the actuator (with the surface control) or the transfer function of the actuator using electromechanical simulation of aeroelastic loading of the surface control, that also used in research stability problems of the system "surface control – actuator".

The article raises the issue of the synthesis of power supply systems for new generation aircraft, which is understood as: the power supply system (complex) of the aircraft, which includes the power and information structures closely integrated. Using this method, the power generation, transformation and distribution functions are assigned to the power structure, and the information structure provides work algorithms. The problematic of the synthesis of the described systems is formed and its relevance is justified. The main work done abroad and on the territory of the Russian Federation aimed at solving this problem are analyzed. As a solution to the problem, it is proposed to use the actual, from the point of view of the authors, method – the structural-functional method. It is shown that the structural-functional method is applicable to solving complex engineering problems, as shown in the examples [16, 18]. The chosen method of solving this problem, like any other one, requires a sufficient number of bench-mark data. When applying the structural-functional method, which is data of the "constraint" type, i.e. GOST (All-Union State Standard) and OST (All-Union Standard) requirements, technical specifications, supplemented by data on possible elements of the synthesized scheme. This article is mainly devoted to the choice of parameters of possible elements of the synthesized circuit, namely primary electric power sources. The article defines a technique for converting discrete values of primary energy sources into functional dependencies, as well as restrictions imposed on their approximating functions. The example shows the obtaining of functional dependencies for mass-energy indicators of nickel-cadmium storage batteries produced by VARTA and SAFT. The analysis of the obtained results is shown, which showed their sufficient reliability and, as follows, their applicability in the development of aircraft power supply systems.

To reduce the cost of field tests of the ballistic objects (BO) simulators reflection properties, it is advisable to develop a model and algorithm for calculation of the radar objects effective surface scattering. As a simulator of ballistic objects a complex radar reflector, made of a lossfree dielectric is chosen. It looks like a spherical Luneburg lens with a coating of high-conductivity alloy as well as a truncated cone, disk, and cylindrical elements. The stages of aperture version of reflection from the inner surface of the Luneburg lens are proposed. A physical model of the reflection on the elements of design and the technique of modeling with a calculation algorithm of the effective surface scattering are developed. The algorithm of calculation of the ballistic objects resonance effective surface scattering is worked out. This algorithm is presented in a graphical form. The interface of the computing complex is presented. As a simulator of ballistic object we selected a complex radar reflector, made of a lossfree dielectric sphere with a coating of high-conductivity alloy as well as of a truncated cone, disk, and cylindrical elements. The comparative indicatrices of ballistic objects simulator are presented. The conclusion on the comparative analysis of the results of measurements in situ and modeling results is made. The examples of numerical calculations of the ESR of the head part of the BO simulator with increased ESR and increased all-aspect view are given. The options of the BO simulator head parts with increased ESR and increased all-aspect view with optimal placement of radar dielectric reflector and a corner unit with sectional placement of dielectric reflectors are analyzed.

Air temperature is one of the most important parameter of the atmosphere. The air temperature, especially in the lower atmosphere can have a significant effect on the aerodynamic characteristics of aircraft and is one of the main elements for the preparation of aviation weather forecasts. Methods of air temperature measuring in the atmosphere can be divided into two groups. The first group which combines the methods of contact measurement assumes the direct contact of the meter with the environment. The second group of methods, is now rapidly developing, combines the methods of remote measurement of the temperature. The problem of remote measurement of air temperature in the lower atmosphere is an important task, since the contact measurements, though highly accurate and informative, are held through certain and large enough time intervals (up to two times per day). To solve the problem of remote measurement of air temperature many different theoretical solutions and technical devices developed on their basis are proposed.  All the proposed methods and techniques have limitations on their use imposed primarily by the precision with which you can define certain characteristics of the studied objects. The article considers a method that opens up the possibility of solving the problem of remote measurement of temperature in non-uniformly heated environment without losses of atmosphere type. It is based on radio emission own reception, intensity of which depends on its temperature. The proposed method of air temperature remote measurement is based on the well-known formula of S. T. Egorov and Y. M. Shestopalov. The article gives reasons for the possibility of using elliptical antennas for air temperature remote measurement in the lower layers of atmosphere.

The basis of modern radar techniques is the direct use of radio-physical data on the power of backscattering. At the same time, the data volume received from the radar allows us to form new estimates and essentially specify classical ones. Significant steps have been made in this direction, using, for example, phase (Doppler) methods. The "modified Rayleigh model" used in radar meteorology to form a scattered field on rarefied medium particles is called the Kerr-Rice model. The main advantage of the Rayleigh model is its simplicity. But it itself contains a deep contradiction, consisting in its logical completion. Based on the statistics study of the first distribution in the rains of varying intensity the authors on a large statistical material have determined the fact of their not Rayleigh form and extreme stability of the latter in relation to natural changes of precipitation intensity. The first distribution is different from the theoretically expected one in the Kerr-Rice model, which makes it possible to use linear-logarithmic detection. It is concluded that the width and the mean of the spectrum of the same signal have the expected dynamics with respect to changes in precipitation intensity and dynamic processes in them. Tables with experimental data are presented. Two main distribution models are considered: lognormal and "logo-gamma-functional". It is concluded that, despite the absence of qualitative differences, the difference in the form of the distributions obtained with different equipment can be a natural consequence of significant discrepancies in the peak power and / or the width of the antenna pattern. The graphs of the first experimental distributions of envelope fluctuations on a linear and semi-logarithmic scale are presented.