The article presents the technique of fuzzy expert assessment of risk that existed at the time an event occurred. The risk assessment is based on matrix proposed by the Airline Risk Management Solution (ARMS) Group. The matrix allows assessing such risks in the numerical values of the conditional average. The values of the indicators in the cells of the matrix obtained by use of data processing got from aviation insurance.In practice the risk assessment that existed at the time of the event is largely based on expert opinions, however ARMS Group does not offer the method of forming estimates expert group total opinion. Conventional methods of expert estimation and averaging of final grades is difficult due to the exponential nature of changes in risk values recorded in thecells, when considered by columns and by rows of the matrix.The proposed method of risk assessment uses the approach adopted in the formation of membership functions according to expert estimates in the theory of fuzzy sets. Experts are invited to classify each event according to one of the categories of potential damage and the effectiveness of barriers parry (defenses) using all available information. Processing of results is conducted using the method of expert analysis of fuzzy data based on the approach of fuzzy set theory. The seriousness (damage) of the occurrence and effectiveness of the barriers considered as linguistic variables, each of which has four term sets. This approach allows taking into account the opinions of experts and obtaining valid estimates of risk do not necessarily coincided with fixed values of matrix cells.

The paper presents a mathematical formulation of the problem formalization of the subject area related to aviation security in civil aviation. The formalization task is determined by the modern issue of providing aviation security. Aviationsecurity in modern systems is based upon organizational standard of security control. This standard doesn’t require calculating the security level. It allows solving the aviation security task without estimating the solution and evaluating the performance of security facilities. The issue of acceptable aviation security level stays unsolved, because its control lies in inspections that determine whether the object security facilities meet the requirements or not. The pending problem is also in whether the requirements are calculable and the evaluation is subjective.Lately, there has been determined quite a certain tendency to consider aviation security issues from the perspective of its level optimal control with the following identification, calculation and evaluation problems solving and decision making. The obtained results analysis in this direction shows that it’s strongly recommended to move to object formalization problem, which provides a mathematical modeling for aviation security control optimization.In this case, the authors assume to find the answer in the process of object formalization. Therefore aviation security is presented as some security environment condition, which defines the parameters associated with the object protec-tion system quality that depends on the use of protective equipment in conditions of counteraction to factors of external andinternal threats. It is shown that the proposed model belongs to a class of boundary value problems described by differential equations in partial derivatives. The classification of boundary value problems is presented.

The authors’ original problem-solution-approach concerning aviation security management in civil aviation applying parallel calculation processes method and the usage of neural computers is considered in this work. The statement of secure environment modeling problems for grid models and with the use of neural networks is presented. The research subject area of this article is airport activity in the field of civil aviation, considered in the context of aviation security, defined as the state of aviation security against unlawful interference with the aviation field. The key issue in this subject area is aviation safety provision at an acceptable level. In this case, airport security level management becomes one of the main objectives of aviation security. Aviation security management is organizational-regulation in modern systems that can no longer correspond to changing requirements, increasingly getting complex and determined by external and internal environment factors, associated with a set of potential threats to airport activity. Optimal control requires the most accurate identification of management parameters and their quantitative assessment. The authors examine the possibility of application of mathematical methods for the modeling of security management processes and procedures in their latest works. Parallel computing methods and network neurocomputing for modeling of airport security control processes are examined in this work. It is shown that the methods’ practical application of the methods is possible along with the decision support system, where the decision maker plays the leading role.

Problems in the sphere of an adverse ecological effect assessment of aerodrome environs aviation noise are analyzed. It is noted, that there is no modern standard and methodical base for such assessment. It is shown that when planning the building, and also when developing noise-protective actions for residential areas in the zones of aviation noise increased level impact it’s most effectively to carry out acoustic zoning of areas near airports borders and flight routes. The system of transport sources noise rationing in Russia doesn't consider the established practice of its application. The aircraft of noisy types were actively taken out of service and aviation noise impact near the airports decreased, but the problem of noise protection, demands control when planning land use. Noise measurements in residential areas, near houses and inside, showed the excess of maximum allowed level values to 25-35 dBA (on equivalent value) and to 25-40 dBA (on the maximum value).As a consequence of the European states policy in the sphere of aviation noise management and of aerodrome environs zoning noise levels at the airports of Europe and their surroundings were stabilized and the sizes of noise contours were reduced. For different countries there was made the analysis of legislative bases of the implementation of the restriction requirement for residential areas and the possibility of using the territory under noise impact. For rationing theaerodrome environs noise of the airports it’s offered to take a sound equivalent level in which admissible values are ranged on three zones for the main standard criterion. The authors present acoustic measurements results in houses near the airport Vnukovo on condition of using standard two-chamber trimmable and folding windows with the ventilating valve. It is shown that the popular window designs can't provide inside noise reduction at night to the standard L Amax level = 45 dBA from the aviation source creating noise L Amax > 75 dBA; sound insulation efficiency of the used blocks is insufficient. Criteria of aviation noise assessment for zoning of the domestic airports aerodrome environs are offered.

The article considers the choice of the lubricants for using in the bolted joints of the serial gas-turbine engine AL-31. In a modern gas turbine engine complex bolted joints operating in various conditions are used. They are subject to demolition in the repair process, in which they break as the result of burning and thus the increase of the breakaway moment. On the basis of maintenance conditions analysis there were determined the most characteristic defects in bolted joints, as well as the reasons for their occurrence. It was established that the main cause of failure of bolted joints is the increase breakaway moment of bolted joint. To reduce the breakaway moment one should choose such lubricants as to reduce the thermal influence on the bolt and prevent it from being destroyed in the disassembly process. For choosing lubrications the analysis of the requirements for lubricants for bolted joints used at high temperatures was conducted. Lubricants choice was made based on the results of a comparative study of various compositions of lubricant application in the process of field testing. This research work is aimed to improve the efficiency of bolted connections in a wide operating range and to prevent the increase breakaway moments in gas-turbine engine repair. Obtained in the process of field testing results allow to suggest a lubricant that can be used in the bolt connection operating at high temperatures and to reduce the break-away moment compared to the commercially used one.

Modern carbon nanofibers (CNF), obtained from polyacrylonitrile (PAN), do not have high tensile strength. It is because there is still no understanding how the electroforming method affects the quality of CNF.This paper investigates a process to obtain high-strength nanofibers with a carbon content of up to 90% by the method of electroforming. The research made it possible to obtain CNFs with a diameter of 150-500 nm with uniqueproperties due to our CNF continuous and combined forms, which distinguishes our CNFs from existing ones when appliedto composite materials. Such nanofibers, obtained by selecting the optimum stabilization temperature and carbonization regime, have homogeneous cross sections, and as a result of improving their mechanical properties, the aircraft structure performance can be substantially improved.

In this paper it is investigated how to make composite carbon nanofiber/ epoxy resin and carbon micro-fiber / epoxy resin. Also, these materials' features are compared and it is shown how effective and benefitial are the received products containing carbon nano- and micro-fibers.In this study, epoxy composites were prepared in order to improve their mechanical and electrical properties. Ergo, carbon nanofibers and carbon microfibers were used as fillers. On the one hand, purchased microfibers were incorporatedinto the epoxy resin to produce epoxy/carbon microfiber composites via mechanical mixing at 1800 rpm in different concentrations (0.0125, 0.0225, 0.05, and 0.1).On the other hand, carbon nanofibers were prepared via electrospining method at room temperature, then epoxy/carbon nanofiber nanocomposites were prepared at mixing temperature of 60 °C at 1200 rpm at different concentrations (0.0125, 0.05, and 0.1).Morphology of samples was investigated via Field Emission Scanning Electron Microscopy (FESEM). Mechanical properties of samples were investigated via tensile and bending tests. Tensile test results revealed that incorporation of 0.0125 wt% carbon naofibers increased the epoxy resins modulus about 200%. Bending strength of sample containing 0.1wt% carbon microfibers had the most increment (from 20 to 100 MPa).

The paper outlines science and methodological aspects of issuing bulletins for the civil aircraft and practical problems accumulated in the national aviation industry within the mentioned area. Bulletins are used to inform operators about the purpose, data content and technologies outlining the design changes accomplishment if the aircraft considered at the moment of the design changes is already at the operational stage. Hence maintaining aircraft airworthiness is impossible without making certain modifications and repairs in the design, the bulletins issuing and implementation procedures have notable impact on safety and effectiveness of air transportation.Deficiencies considered are the results of practices used since 1980 and supported by the later interstate standard GOST 31270-2004 in the field of the bulletins development and implementation, which are not in line with contemporary conditions of international civil aviation activities. Negative consequences of transferring the Soviet way of working with aircraft bulletins intothe changed conditions of the state regulation of civil aviation activities in Russia are shown as well as those for substantial com-plication of the rules and procedures in comparison to the standards of Unified System of Design Documentation.Main theses of the ICAO standards and international practice are briefly analyzed, however they are not completely presented in the national aviation regulations. The recommendations proposed are aimed to eliminate mentioned deficiencies through the standards amendment process and improvement of Russia's civil aviation regulatory base. Developed recommendations are mainly focused on the formulation of the new concept and certain content of the revised standard requirements to replace GOST 31270-2004.

The solution of the problem of modelling and quantitative assessment of flight safety risk is being considered in this paper. The article considers the main groups of mathematical models used to quantify the risks of flight safety, which can be used by providers of aviation services. The authors demonstrate and discuss risk modeling possibilities in the field of flight safety on the basis of Bayesian belief networks.In this paper a mathematical model is built on the basis of identified hazards, and this model allows to determine the level of risk for each hazard and the consequences of their occurrence using Bayesian belief networks, consisting of marginal probability distributions graph and conditional probability tables. This mathematical model allows to determine the following, based on the data on adverse events and hazard identification: the probability of various adverse events in all dangers occurrence, the risk level for each of the identified hazards, the most likely consequences of the given danger oc- currence. For risk modeling in the field of flight safety on the basis of Bayesian belief networks there were used supple- mentary Bayes Net Toolbox for MATLAB with open source. To determine the level of risk in the form specified in ICAO Doc 9859 "Flight Safety Management Manual" of the International Civil Aviation Organization, the authors wrote a func- tion to MATLAB, allowing each pair of probability - to set severity level in line with alphanumeric value and significance of the risk category.Risk model in the field of flight safety on the basis of Bayesian belief networks corresponds to the definition of risk by Kaplan and Garrick. The advantage of the developed risk assessment method over other methods is shown in the paper.

Russian Federation is entering a new system of Occupational standards as norm of competence that people are expected to achieve in their work, and the knowledge and skills they need to apply effectively. There may be conflicts in professional co-operation between the new system of Occupational standards and the old system of Managers, specialists and workforce qualification reference books. It may affect the common area of occupational environmental hazards. Employees, who passed compulsory medical examination, can have poor health conditions. It affects the inability of the employees to perform their aircraft maintenance duties. It may be a particular occupational environment factor. A five-point scale of possible damage severity was proposed for this factor. It is known that a sick employee's duties are redistributed among the remaining employees. Redistributing of a sick employee's duties increases the task load of the remaining ones in terms of overtime work for instance. It, ultimately, may compromise normal operation of employees. The results can be used when taking management decisions in process organization of airlines, as well as in other industries.

The modern approaches to the aviation security screeners’ efficiency have been analyzedand, certain drawbacks have been considered. The main drawback is the complexity of ICAO recommendations implementation concerning taking into account of shadow x-ray image complexity factors during preparation and evaluation of prohibited items detection efficiency by aviation security screeners. Х-ray image based factors are the specific properties of the x-ray image that influence the ability to detect prohibited items by aviation security screeners. The most important complexity factors are: geometric characteristics of a prohibited item; view difficulty of prohibited items; superposition of prohibited items byother objects in the bag; bag content complexity; the color similarity of prohibited and usual items in the luggage.The one-dimensional two-parameter IRT model and the related criterion of aviation security screeners’ qualification have been suggested. Within the suggested model the probabilistic detection characteristics of aviation security screeners are considered as functions of such parameters as the difference between level of qualification and level of x-ray images complexity, and also between the aviation security screeners’ responsibility and structure of their professional knowledge. On the basis of the given model it is possible to consider two characteristic functions: first of all, characteristic function of qualification level which describes multi-complexity level of x-ray image interpretation competency of the aviation security screener; secondly, characteristic function of the x-ray image complexity which describes the range of x-ray image interpretation competency of the aviation security screeners having various training levels to interpret the x-ray image of a certain level of complexity. The suggested complex criterion to assess the level of the aviation security screener qualification allows to evaluate his or her competency taking into account not only the average level qualification, but its possible variance. The important feature of implementing IRT models logistic functions is the necessity of preliminary selection of test images. Test x-ray images have to be selected in the ascending order of their complexity taking into consideration the influence of various factors.The suggested model may be applied both in the field of improving of aviation security screeners’ training methods to provide screening procedures, and while solving problems of increasing the efficiency of the screening system functioning.

This article is devoted to basic statements according to scientific researches carried out in the area of airworthiness maintenance and aimed at creation of monitoring system of the aircraft equipment resource condition for the purpose of its resource and service life parameters control.The term monitoring is used here as consecutive process of obtaining, processing and analyzing the information on resources and aircraft equipment service life (planes, helicopters, aircraft engines and their accessories) with the further use of this information for the problems solution of its own air fleet structure management, its updating and forecasting indicators of its operation processes efficiency.The most important and complex components of monitoring system and aircraft equipment resource condition, in particular are noted: the personified approach to the definition of aircraft equipment rational resources and service life; models of forecasting and aircraft resources processing management; decision-making models on increase of long life aircraft parameters taking into account maintenance cost; justification of expediency of aeronautical products retrofit by way of increasing their resource characteristics; definition methods of resource products necessary quantity by using of statistical model; assessment methods of aviation components authenticity value; models of technical and economic efficiency of works on increase in individual resources of removable parts.Certain components of monitoring system are considered in more detail with the references indication.

At the present stage of aviation and missile equipment development there is increasing necessity for considering fast-acting, high-speed processes of impact interaction of structure elements with external loads, represented as both power factors (longitudinal force or bending moment) and uniformly spread aerodynamic pressure. The article analyses the dy- namic behavior of the nonuniformly-heated thin conical rotational shell, modelling the aircraft heat shield, under pressure wave loading in a gaseous environment. Stress-strain shell behavior caused by preliminary uneven heating is determined by solving thermo elastic equilibrium equations. The temperature field can be specified as any functional dependence in both circumferential and longitudinal coordinates of a thin-walled axisymmetric shell. The solution of the dynamic problem is obtained by the integration of shell and attached mass motion nonlinear equations under predetermined initial displace- ments, zero initial rates, and boundary conditions appropriate for heat shield fixation. The work presents simultaneous equations solution in the form of time dependent behavior from the beginning of front external pressure impact for dis- placements and stresses in thin-walled structures. The dependent behavior for various shell designs is presented taking into account the changes of shell thickness and attached mass. It is shown that the initial conditions of non-uniform shell heating cause leading-edge deflection comparable in size to the magnitude of the displacements from its free oscillations. However the values of stresses in a shell for its fixation area are more dependent on its thickness, than on the magnitude of the at- tached mass.

The main priority of any air company activity and the main condition for its development is the achievement of the highest flight safety level. Significant positive results in this area have been recently achieved, hence, the relative stagnation of indexes, reflecting the flight safety as a condition of air transport system, has been revealed. It has become evident that the present accident prevention philosophy seems to be exhausted, and at the current stage of development it doesn’t allow to make a breakthrough in the solution of all the problems, which air companies face in this respect. In the perspective to find new ways to solve the existing tasks, in 2011, International Civil Aviation Organization Council adopted fatigue risk management international standards as an alternative for the traditional approach to managing crewmember fatigue by prescribing limits on maximum daily, monthly and yearly flight and duty hours. It’s a well-known fact that state of fatigue has a special place among the functional states, which are professionally significant for airmen work and which are the key link in “man-aircraft-environment” system.In this article, fatigue is considered to be a risk factor that contributes to the formation and development of crew violations and errors in the process of piloting the aircraft. We have analyzed the characteristics and reasons leading to inflight fatigue and estimated its influence on crew performance, considering the interrelation between them. The article specifies the methods and techniques to measure pilots fatigue; besides it has been substantiated the necessity of fatigue risk management system development in airlines to effectively ensure the flight safety.

The article considers the technique of the synthesis of non-linear aircraft control systems by flight optimization us- ing inverse dynamics problems. To synthesize control algorithms a non-linear model of aircraft flight and trajectory movement is used. The authors define method stages of flying level synthesis which include: selection of aircraft reference movements in accordance with three degrees of freedom, structuring the control algorithms and their parameters, defining the proximity of current and reference movements by means of a quadratic functional and further extremum-minimum movement organization by the gradient method. Through the optimized parameters of flying level the direct dynamics problem of trajectory level control of the aircraft spatial movement is solved. The basis for calculating the aircraft trajecto- ry parameters is a non-linear model of the trajectory movement for which flying level output parameters serve as input data. The trajectory level output parameters are defined by numerical integration of input signals considering aircraft dynamic blow coefficients. The structure diagram of aircraft spatial movement control organization is developed. The flight contour functioning is examined using numerical modeling in MathCad and Paskal programs. Reference parameters were determined by Paskal simulation modeling according to the reaction of a non-linear aircraft model to the “bounces” of aerody- namical flight controls. It is shown that the spatial control problem is optimal in terms of input control realization. Besides, in comparison with [9] it is possible to state that due to energy reversibility of rotational and progressive movements only the content of direct and inversed problems of dynamics changes.

Simulation experiments performed while solving multidisciplinary engineering and scientific problems require joint usage of multiple software tools. Further, when following a preset plan of experiment or searching for optimum solu- tions, the same sequence of calculations is run multiple times with various simulation parameters, input data, or conditions while overall workflow does not change. Automation of simulations like these requires implementing of a workflow where tool execution and data exchange is usually controlled by a special type of software, an integration environment or plat- form. The result is an integration workflow (a platform-dependent implementation of some computing workflow) which, in the context of automation, is a composition of weakly coupled (in terms of communication intensity) typical subtasks. These compositions can then be decomposed back into a few workflow patterns (types of subtasks interaction). The pat- terns, in their turn, can be interpreted as higher level subtasks.This paper considers execution control and data exchange rules that should be imposed by the integration envi- ronment in the case of an error encountered by some integrated software tool. An error is defined as any abnormal behavior of a tool that invalidates its result data thus disrupting the data flow within the integration workflow. The main requirementto the error handling mechanism implemented by the integration environment is to prevent abnormal termination of theentire workflow in case of missing intermediate results data. Error handling rules are formulated on the basic pattern level and on the level of a composite task that can combine several basic patterns as next level subtasks. The cases where workflow behavior may be different, depending on user's purposes, when an error takes place, and possible error handling op- tions that can be specified by the user are also noted in the work.

The research considers the activity based network of routines performed by the integrated servicing crews at the airport. The known algorithms for critical path claiming suppose that the activity duration is given and the beginning of any activity is determined. However, the beginning of the activity also depends on the presence of the necessary resources for the given period of time.The formal statement of the problem is described. For the solution of the problem the well-known algorithm for constructing the tree of the shortest paths of the network graph is used. Herewith we suppose, that activity durations are known and resources are sufficient in order to start each activity at the right time. Further, this algorithm is modified inorder to take into account available resources. The special two-dimensional matrix with rows showing resource units andcolumns denoting the equally separated time intervals is used to demonstrate the resources state. The numerical method is proposed for solving the optimization problem. The method is implemented using the Mathcad computing environment and validated by specific examples.The method is implemented as a complex automated solution for operational management of airport services in the critical situations.