A significant interest of researchers is attracted to the effective management and forecasting of exchange processes in the boundary layer, which are key for the implementation of effective and reliable equipment. Modeling of exchange processes occurring in a high-speed dispersed boundary layer with external influences is a very difficult task. Mathematical modeling allows us to develop reliable devices and engines for the fields of aircraft, energy, shipbuilding with minimal costs for its creation. Despite the interest of numerous groups of researchers around the scientific projects and a large number of works, the current theory of the boundary layer is imperfect. This may be due to several circumstances: firstly, the theory of single-phase turbulent flows of continuous media is far from being completed, secondly, turbulent flows with dispersed impurities in the form of particles greatly complicate the already intricate flow pattern. Interest in dispersed flows is particularly relevant due to the fact that almost all gas-dynamic flows contain a certain concentration of particles, and their impact can provoke significant changes in the structure of the boundary layer and affect the intensity of exchange processes. The article proposes a two-fluid mathematical model describing the motion of a high-speed dispersed boundary layer on a surface with hemispherical damping cavities. The use of hemispherical damping cavities allows to reduce turbulent exchange in the boundary layer, which makes it possible to control the intensity of metabolic processes. The possibility of a significant reduction of turbulent heat transfer and friction in the dispersed boundary layer is established. The proposed method of impact on the turbulent transport in the boundary layer will improve the equipment and installations, including GTU and GTE used in various industries of our country, such as energy, aircraft, shipbuilding.

The authors consider the problem of optimization of aircraft flight trajectories in air traffic management (ATM) on the basis of flexible routing technologies which involve the use of satellite navigation systems (SNS). It is shown that in optimizing a trajectory it is necessary to take into account the accuracy of track holding during the flight which depends on the accuracy of the navigation system and external flight path disturbances, e.g. wind. For solving the task of optimization the authors propose to use the theory of graphs. The technique of constructing a dynamic SNS accuracy field and representing it as a graph was developed. It is proposed that the SNS field be characterized by geometric dilution of precision changing both in space and in time. Based on the theory of graphs (A-star algorithm) the technique of constructing a trajectory of optimal length with changing the SNS accuracy and external flight path disturbances is proposed. The criterion of optimization based on minimizing the true track is offered. The cost function taking into account the track holding accuracy in navigating by SNS and effects of external flight disturbances is justified. The article presents the results of A-star algorithm application for constructing an optimal flight trajectory under conditions of SNS accuracy field variation and presence of prohibited zones in the provided airspace.

Training of cadets-air traffic controllers and cadets-pilots is an integral part of the training, which allows you to form the skills of quick and correct decision-making in different types of situations. For the air traffic controller, these are exercises to solve conflict situations with aircraft in the area of their responsibility, solving problems in normal flight conditions, in unfavorable atmospheric conditions and in the non-routine situations in flight. For the pilots, solutions to the problems are reduced to the rapid decisionmaking on aircraft control in normal flight conditions, adverse atmospheric conditions and non-routine situations in flight. As you know, the work of air traffic controllers is associated with the work of pilots, but training in educational institutions takes place separately, resulting in gaps in knowledge of the specifics of the adjacent specialty, and, eventually, leads to errors. Optimization of the educational process is currently an urgent task. The program of joint training can act as an optimization tool. The program enables you to collaboratively practice the skills of fast decision-making, clearly to learn the specifics of the related specialties that will allow you to create a complete picture of the air situation. The program of joint training implies the joint operational logic simulator that combines two simulators. For the air traffic controller, this is a separate airspace area in the form of a sector, for the pilot it is the cockpit. Thus, the solution to the problems occurs sequentially from the air traffic controller to the pilot and vice versa, and the controller has the ability to observe the algorithm of the pilot's actions, and the pilot is able to monitor the algorithm of the controller's actions.

Accuracy of aviation weather forecasts is one of the main indicators characterizing the quality of meteorological support of flights. A significant influence of the quality of meteorological support on flight safety and regularity is confirmed by the results of the annual tests conducted by the Federal Agency for Air Transport of Russia and "Aviamettelecom of Roshydromet". Currently, the quality of meteorological support of flights is still at a low level compared to countries that are recognized leaders in the aviation industry. To develop high-quality weather forecasts for the airfield weather service requires a large amount of information, which is based on the data of meteorological measurements and observations obtained by aerodrome meteorological systems. The lack of reliable information about the value of meteorological parameters of the atmosphere does not allow the weather man to form a qualitative weather forecast, so there are cases when the weather forecaster of the airfield weather service gives a reinsurance forecast. At the same time modern airfield meteorological systems have sufficiently advanced systems and devices for measuring the parameters of the atmosphere. The full use of all the advantages of these systems for the development of high-quality weather forecasts and, therefore, to improve their accuracy can be achieved through integrated processing of the meteorological information received. The most important characteristic of the atmosphere is the air temperature at aircraft flying altitudes. Reliable knowledge of the temperature profile largely determines the justification of weather forecasts and forecasts of dangerous weather events for aviation. The article considers, as an example, the algorithm of complex processing of information about the temperature profile in the aerodrome area, the structural scheme of the algorithm is obtained and te results of modeling the temperature profile and its complex evaluation are presented.

The engine failure, according to the flight safety inspection of the Federal Air Transport Agency, caused 4 of 6 aviation accidents in 2017, including 2 air disasters. In general, from 2001 to 2017, events related to the engine failure became the second most frequent cause of aviation accidents (13% of aviation accidents and 12% of air disasters). The worst consequences are associated with the engine failure at the most difficult and crucial stage of the flight landing. For example, it was the engine failure on the final approach that caused the crash of the L-410UVP-E20 RA-67047 aircraft near the Nelkan airfield on November 15, 2017. The article discusses a limiting situation in some sense – the landing of an aircraft with all failed engines under the wind conditions. The authors have proposed for this situation a methodology of calculating the landing approach of an aircraft under the wind conditions in case of failure of all engines of its power plant to an aerodrome equipped with an outer marker. The key features of such methodology are, firstly, the absence of necessity to link the path to the landmarks in the landing aerodrome area, and, secondly, the simplicity of the synthesis and the implementation of the aircraft control based on the proposed methodology during landing in both manual and director or automatic modes. To calculate the approach using the proposed methodology, the crew only needs to know the following values: the minimum drag airspeed on final approach, the height of the flight over an outer marker before landing and spiral approach leg. The content of the methodology in the article is illustrated by the results of the approach calculation when all of the main engines of the Russian short-medium-range MS-21 aircraft fail under the wind conditions.

When designing a stabilization system for highly maneuverable unmanned aerial vehicles (UAVs), one of the relevant tasks is to impose requirements on the dynamic characteristics and control methods of the steering actuators, which will ensure the required stability margins of the stabilization system as part of the UAV control system. Currently, there is an increasing preference for microcontroller method of electric actuator control and digital exchange between the control system and the steering actuators. One of the reasons for the reduction of stability margins of the stabilization system is the delay introduced by the digital exchange between the elements of the stabilization system. In the process of solving the problem of transition to digital exchange between the elements of the stabilization system, a research was conducted of the influence of amplitude and phase distortions arising in the path "data transmission interface steering actuator" on the dynamic characteristics of the steering actuator. As an actuator of the stabilization system, the real electric drive used on highly maneuverable UAVs is considered. For this drive, extremely stringent requirements for bandwidth and phase delays are introduced, which complicates the problem of ensuring the stability of the stabilization system, taking into account the delays in the digital exchange. As a result of the research, a frequency model has been proposed that allows to estimate the minimum possible exchange rate in the path "data interface steering actuator", taking into account ensuring the required dynamic characteristics of the actuator. In the proposed model, the data transfer interface is represented as a zero-order hold, the transfer function of which is replaced by Pade approximations of the second order. In the course of the research, a comparison was made of the results obtained on the proposed model with the results of experiments on a real electric actuator and its complete nonlinear time model. The main advantage of the proposed frequency model is the simplicity of obtaining the transfer function of the path "data interface steering actuator". This allows at the initial stage of the research to quickly and accurately determine the minimum possible rate of exchange, which will ensure the fulfillment of the requirements imposed on the drive dynamics.

Modern trends of civil aviation development indicate the need to improve fuel efficiency and environmental friendliness of the utilized fuels. The use of conventional jet fuel is meeting to a lesser degree the promising requirements concerning environmental friendliness at a constantly rising price for it. Apart from that, oil reserves are limited. According to many experts, the solution to the growing problems with oil fuels can be application of alternative types of aviation fuel. A number of companies around the world, together with aircraft manufacturers under the significant state support, are actively developing new types of fuel. At the moment the most widespread biofuels consisting of bioethanol are obtained from various plant and animal sources. Alternative fuels should not be inferior to petroleum fuels in its operational properties. A possible transition to them should not require significant costs for the modernization of aircraft and facilities of ground aviation fuel supply. Therefore, an urgent task is to compare the main indicators of the quality of oil fuels, biofuels and their mixtures to assess the possibility of using biofuels on aircraft. A comparative analysis was carried out on some quality indicators. Afterwards the comments were given on the impact of changes of these quality indicators on the performance properties of the fuels. It is shown that according to some quality indicators, biofuels under research have the advantages over oil ones. The relevance of comprehensive study of the performance properties of biofuels is obvious. The improvement of oil fuels and their comprehensive study have been under way for more than 60 years. Biofuels are just beginning their life, so it is reasonable to conduct thorough research on their use in aviation.

The article proposes a formalization methodology of the basic characteristics of the production processes of the aviation industry major components, such as airlines, airports and air traffic control authorities. This technique is not exhaustive, but it is quite suitable as the basis for the formation of the initial data for decision-making optimization under the conditions of airport operations performance and air traffic management, based on the principles of work coordination of the airports operational units. It is proposed to use a genetic algorithm as a tool for optimizing collaborative decision-making, which allows for a smaller number of iterations in real time to obtain a suboptimal solution that meets the requirements of the process participants. The mathematical model in multiplicative form is presented in making an assessment of the application feasibility of the genetic algorithm, taking into account the interests of three stakeholders. Planning the use of aircraft for the airport flight schedule based on the formalized data of the airline fleet, the capabilities of the base airport apron, as well as the restrictions of permanent and temporary nature is accepted as the original product. The article demonstrates the potential advantage of the genetic algorithm, the point of which is that within each step of a suboptimal choice of priorities instead of brute-force options limited but effective direct search of a reduced number of those options that have been chosen as the "elite" by using multiplicative form is carried out.

The article proposes the probability determination technique of timely aircraft departure, which is based on mathematical modeling method. It is proposed to use the indicator of timely departure probability, a calculation method of which is different from the known methods by taking into account the aircraft maintenance and repair system. This technique applies modern information technologies and the adopted approach is also supplemented with the mathematical model software implementation. The method of aircraft timely departure probability calculation is based on the model of the aircraft maintenance and repair system, utilizing the theory of mass service mathematical apparatus. The technique allows us to achieve the practical objectives of flight tests implementing aircraft maintainability evaluation and also complements the existing methodological support of the tests. The developed computer program provides the calculation of the required indicators for various values and combinations of factors which influence the result. Modeling was performed, and the study results of the main factors of probability effect, influencing timely departure are presented. Eventually the basic laws in solving the problem of aircraft timely departure, including interception of flying object are established.

The article deals with a number of approaches to the use of electrooptical systems and unmanned aerial vehicles (UAV) to solve the tasks of live terrain surface screening, air incident spots and objects survey. The paper provides the grounds for the UAV airframe chosen structure and the design of the electrooptical complex. The light weight, high -wing monoplane airframe structure is suggested. Using the CNC production center, a UAV with high aerodynamic performance was developed. The UAV was fitted with the optoelectronic system. Structural design for the airborne and ground equipment of the survey complex was developed. The structural design comprises the forward-looking and side airborne surveillance cameras and also downward-looking cameras of visible and infrared bands to provide the day and night vision. The downward-looking cameras of visible and infrared bands, integrated into the UAV fuselage belly are used for the surface monitoring and survey. The flight test on the use of electrooptic system comprised the flight on the route and automatic return using the satellite system navigation. The test showed that navigation data correction was required. The positioning accumulative error elimination is suggested to be done via automated image registration with the contour extraction and landmark reference. The image processing results using Canny algorithm were presented. The recommendations on the algorithm practical application and speed of response are given. To solve the problem of terrain on-time surveillance and monitoring the flight routes were subjected to research. Based on the experiments performed, the recommendations were given on the electrooptic complex application and flight route plotting for the tasks of on-time search and rescue.