The formulation of the flight safety history problem is stated. The article shows that it is problematic to scientifically substantiate, systematize, analyze and generalize the theoretical and empirical flight safety material accumulated in various fields. From a historical perspective, the necessity for a socio-humanitarian assessment of the transformation processes of scientific and applied experience in the field of flight safety is substantiated. New multidisciplinary line of research, making use of a specific scientific apparatus and methodological tools, i.e., the history of flight safety, the subject basis of which covers social activities throughout the life cycle of all aerospace engineering (artificial flying objects in the Earth's atmosphere and space, aircraft, crews, passengers, other aerospace system specialists), including aeronautics, aviation, cosmonautics over a span of the entire history of mankind, is proposed. A brief overview of publications on the issue of flight safety is offered. The experience of flight safety history research is analyzed. The periodization of flight safety history in the XX–XXI centuries, giving prominence to three stages: 1. Generating ideas, technologies, flight safety systems (10–40s of the XX century). 2. Establishing the national and international systems to ensure flight safety, scientific research, personnel education and training in the field of flight safety (50–80s of the XX century). 3. Developing new ideas, technologies, projects, flight safety management systems, active ensuring of flight safety, etc. (since the 90s of the XX century), is proposed. The foundations of the conceptual model of the flight safety history are presented, the methodology, experience and prospects of research are considered. It is recommended to organize systematic studies of the flight safety history, covering the aspects of the world and domestic science, education and practice; to create a unified information system on the history of flight safety based on new information technologies, the ultimate aim of which can be a virtual worldwide museum of flight safety; to initiate a pilot project of the National Flight Safety Museum of Russia and to start its development in the year of the 100th anniversary of our civil aviation; in the future, to develop a new academic discipline "History of Flight Safety" for training aerospace industry specialists and researchers.

At present, the process of design and production of unmanned aerial vehicles has been making progress in Russia, which is caused by the relatively low cost, small size, absence of life hazard to a pilot, stealth, self-sustainability, mobility compared to manned aircraft. At the same time, two-stroke gasoline engines, possessing a higher power-to-volume ratio, unsophisticated design, and lower production costs in comparison with four-stroke gasoline engines, have become widely used in these aircraft. These engines lack a conventional lubrication system, so the oil is supplied to lubricate the cylinder-piston group in the form of a fuel-oil mixture, which burns during the operating procedure together with the fuel. In this case, high-temperature deposits such as carbon and lacquer are accumulated on the parts of the cylinder-piston group. The formation of carbon reduces the engine power, its service life and efficiency, causes an increase in operating costs. One of the solutions to this problem is the use of motor oils with a high level of anti-carbon properties. However, currently a method for assessing the anti-carbon oil properties for unmanned aerial vehicle engines is not available. In accordance with the described chemmotological process, the method was developed, the test equipment (Panel Coking Test Apparatus) was selected and the test modes were established (plate temperature – 290°C, oil temperature in the crankcase – 100°C, spray speed – 800 rev/min, test time – 4 h), allowing you to evaluate and rank motor oils for unmanned aircraft engines based on the anti-carbon properties in the laboratory. As tested, Motul Kart Grand Prix 2T oil has the least tendency for carbonization among tested motor oil samples. Laboratory and bench tests of Novoyl-DD and Motul Kart Grand Prix 2T oils show a high degree of convergence.

During aircraft operation, the assessment of operation parameters with the different use of nomograms is completed. This approach is prevalent in the operation of aviation gas-turbine engines as part of aircraft power plants. In this case, for example, the assessment of engine operation parameters on the ground, depending on environmental conditions prior to start-up and run-up, is required. Reducing working hours of the aircraft power plants maintenance can be provided by the automation of the denoted procedures which purpose is the formation of the applicable list of values for assessed parameters while assigning available environmental conditions considering the required restrictions. To allow for the visualization and familiar conceptions of carried out assessments, it is advisable not to be limited to only documenting quantitative parameter estimations but also to provide them with graphical representations. The purpose of the article is not aimed at describing a complete algorithm of the engine operation parameters assessment but demonstrating a solution capability for the automation of the procedures for the engine operation parameters assessment on the ground as the task of search for a solution in the restricted conditions using the approximation 30 apparatus and piecewise approximations by the method of the smallest squares and the correlation criterion of significance. The examples of quantitative estimations for one of mass domestic engines are given. The described approach is applicable to a broad list of engines due to the common character of algorithms for the parameter assessment using nomograms. Software based on the tabular calculation processor from the LibreOffice package, Apache-licensed free software, is cross-platform.

To comply with efficiency in terms of strength, stability and weight of the aircraft, a complex problem for designing a structural layout should be solved. At the same time, it is essential to take into consideration optimization of the shape, quantity, component layout. Now, the main variant of a structural layout is a combination of longitudinal and transverse elements, optimization of which has virtually exhausted itself. The use of polymer composite materials based on glass and carbon fibers, possessing high specific performance compared to metals, makes it possible to improve the performance of a product and additionally optimize a frame structure due to anisotropy of material properties. However, fundamentally innovative structural layouts are needed for further improving properties. It has become practical to create new promising structural layouts due to the development of technologies for manufacturing products from composite materials, including additive manufacturing and 3D printing as well as developing methods of mathematical modeling and computer-assisted design. Bioinspired structures based on natural analogues such as insect wings are attributed to them. The paper is devoted to a highly topical problem of searching and selecting innovative structural layouts. The purpose of the article is to reduce aircraft fin mass while providing structural strength. The paper considers five variants of structural layouts inclusive of the conventional original structure. Aerodynamic loads on the structure were determined by modeling the flow-around process at an assigned flight mode. Stress-and-strain behavior of the structural layout was determined, and the optimal variant of the considered was chosen. The advantage of polymer composite bioinspired structures over conventional metal variants was established. The paper results will be taken into consideration and used in the subsequent optimization of structural layouts and the development of methods for choosing structural layouts.

The increasing need to obtain data on the meteorological situation to ensure the safety of aircraft flight actualizes the development of radar systems for remote collection and processing of information, including for solving the problems of classifying dangerous weather phenomena. This determined the primary development of the domestic weather radar complex of the near airfield zone (WR BZ). The article presents the features of the construction of the WR BZ, as well as the main tasks it solves. To classify meteorological phenomena from cloudiness to squall in the weather radar complex of the near airfield zone, it is proposed to take as a basis the criteria tested by weather radar stations of previous generations. These criteria are based on an analysis of the height distribution of reflectivity, taking into account the vertical temperature profile. In addition, a criterion for classifying thunderstorms in the cold period of time has been additionally introduced in the WR BZ. To calibrate the values of the criteria, a mathematical apparatus and special software were developed. To collect statistical data, WR BZ were installed in various climatic regions: the Central and North-Western Federal Districts and the Republic of Crimea. Further, an effective validation of the information received was carried out. At present, WR BZ has passed preliminary, acceptance, certification tests, trial operation, while demonstrating an effective classification of meteorological phenomena, thanks to the correct selection of decision criteria. The article considers the possibility of increasing the reliability and justification of the classification of dangerous meteorological phenomena through the additional use of information on the distribution of altitudes of the specific rate of dissipation of turbulent energy of the atmosphere, as well as an additional set of statistical data in various climatic zones of the European territory of Russia – the Upper Volga Region and the Krasnodar Region. 

The use of pulsating subsonic gas flow treatment (gas pulse treatment) in the process of maintenance and repair for a duration not exceeding a certain value contributes to the restoration and improvement of mechanical and operational properties of aeronautical equipment structural elements. This article presents the results of a study to determine the optimal duration of gaspulse processing of aircraft parts, as which, the duration of processing was adopted, providing the maximum increase in the properties of material viscosity, which prevents crack development without reducing the strength properties. As a result of the study, the influence of various factors, such as the subsonic airflow velocity and the frequency of oscillations, the material and geometric parameters of the processed product, on both the optimal and leading to a decrease in mechanical properties duration of processing by pulsating airflow of aircraft structural elements during maintenance and repair, was evaluated. It has been established that mechanical waves generated by gas flow pulsations can have a significant impact on the structural strength of aircraft structural elements, which makes it possible to increase their reliability as well as the accuracy of forecasting the technical condition. The harmonic nature of the attenuation of the ratio of residual stresses to their initial values has been experimentally established, depending on the duration of gas pulse treatment, which allows us to control their magnitude and sign. An empirical formula has been obtained to determine the optimal processing time for products of various materials. As an indicator of the duration of gas pulse treatment, an increase in the viscosity of the material was adopted without reducing the strength properties. Graphical dependences of the relative time of gas pulse processing, which provides an increase in the mechanical properties of the relative frequency of the gas flow oscillations, have been constructed.

 One of the success indicators for any new aircraft is its fuel efficiency, influencing both range and cost-effectiveness, as fuel costs amount to 30% of direct operating costs. Based on the analysis of take-off mass response to design changes, a solution to the basic-type aircraft improvement in terms of fuel efficiency is considered. The feature of proposed redesigning is the use of a higher aspect- ratio of an airfoil allowing for fuel efficiency to be increased by reducing the induced drag. Two solutions are considered to substantiate this approach. The first one is the transition to composite wing structures, which will allow for a high aspect ratio of an airfoil without losing rigidity. The second one is the application (if necessary) of devices, reducing the wingspan, caused by the airport restrictions. The methodology for assessing the mass of composite wings based on the universal weight formula by V.A. Komarov which was specified by applying an integral factor considering the features of mass distribution in the structure, the structural adaptation of structure elements and their strength performance, has been proposed. To simplify the arrangement of aircraft with large-span wings in the available airport layout, the application of folding wingtips was considered. The principal analysis of the wingtip swiveling unit structure was performed. The assessment of the folding device effect upon the mass of a passenger aircraft was completed. The proposed approach was verified based on the Boeing company of B777 aircraft family. The numerical analysis of the composite wing application for the IL-96, Tu-214 and SSJ-100 was performed, and the winglet use effect on the MC-21 aircraft was studied. 

Currently, the big number of companies, and specifically in Russia, is engaged in designing unmanned aerial vehicles (UAV). It is caused by the tendency to reduce human labor in various fields of activity, in particular, associated with a great risk to life and health. All these factors lead to the steady growth of different-type missions for the UAV application. Urgency of the research generates considerable interest towards the issues of the UAV application. As part of developing a method for determining UAV design parameters, the author analyzed the results in this domain, considering the operation in a group of aircraft. In order to propose a conceptual aircraft solution for designing a model, the analysis of target objects for the UAV group application was conducted. The article considers various target objects for the application of UAV groups. The result of the analysis for target objects can form the basis for the conclusion involved with the imposed requirements for the design of this UAV class. Compared to other specialists’ articles, this paper is distinguished by synthesizing the achievements in the sphere of group-operated UAV design, as well as by establishing the basic trends for their application while conducting warfare.