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Civil Aviation High Technologies

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Vol 25, No 6 (2022)
View or download the full issue PDF (Russian)
https://doi.org/10.26467/2079-0619-2022-25-6

TRANSPORTATION SYSTEMS

8-22 335
Abstract

The article considers the restrictions algorithms for the trajectory parameters of aircraft motion. Three groups of algorithms are under consideration. They are distinguished by the volume of airborne database about terrain, modes of aircraft operation. The first group (the full SFITA mode) uses the maximum digital cartographic information (DCI) about the terrain. In the SFITA algorithms, the terrain is approximated in the form of planes in space in some predictable, pre-emptive area in the flight path direction. Terrain following is carried out in space in the assigned direction. The equation of the adjacent plane is solved. The distance, the approach speed, and the time to reach the plane are enumerated. The net acceleration to reduce the approach speed to the plane of restriction is calculated under the specified constraint controls. The required time is calculated to reduce the approach speed towards the obstacle to zero. Having equated the expressions for the time of reaching and the required time, transition towards the distance to the plane of restriction, on which it is imperative to utilize constraint controls. The second group (the major SFITA mode) uses the DCI about the terrain in the direction of track in a pre-emptive area. The terrain is approximated by a line in the plane. The specified normal overload is used as a means of control. Terrain following is conducted in the vertical or slant planes. Subsequently, the same procedures are used as in the first group. The third group (the minimum SFITA mode) does not use DCI. The radio and barometric pressure altimeters are used as information systems about the terrain. The given SFITA mode is selected only for flights in a flat terrain. The algorithm includes the similar procedures as in the first and in the second groups. The analytical analysis, confirming the adaptive properties of algorithmic support based on the fundamental law of uniformly retarded motion, is given. The considered algorithms efficiency is confirmed by a comprehensive amount of simulation. The presented algorithms can become the foundation for developing Russian TAWS analogues.

23-39 337
Abstract

Air transport for the Far East and the Far North is a strategically important mode of transport for most of its part and especially in the Arctic regions. Air transportation plays the most important social and economic role, providing the fastest connection with the rest of Russia and vital transport accessibility of the population of a strategically important region of the Russian Federation. Air transport plays a special role in the largest region of the Russian Federation, the Republic of Sakha (Yakutia), which remains the most isolated and inaccessible region of the country. In the republic, aviation is the only year-round means of transport communication on 85% of the territory. At the same time, the most important factor affecting the year-round provision of transport accessibility for the vast majority of airports in the republic, and especially in the Arctic zone, is the delivery of the required amount of aviation fuel, provided that its consumer properties are preserved. The unique and complex scheme of aviation fuel delivery to the Arctic and remote areas of Yakutia, with up to nine transshipments, leads to the loss of some important parameters of aviation fuel, such as electrical conductivity, and forces airlines flying to the Arctic and remote areas of Yakutia to look for more optimal logistics ways of delivery, storage, ensuring the safety of properties and parameters of aviation fuel. Another factor that directly affects the year-round provision of transport accessibility of the population is the cost of jet fuel, which is about 30 % of the costs of base airlines, such as Yakutia Airlines, where at the base airport Yakutsk the cost of jet fuel in 2021 reached 88 thousand rubles per ton, provided refueling in the wing, with an average value for all airports Russia has about 58 thousand rubles per ton. At the same time, the cost of jet fuel at Arctic airports has approached or has already reached 100 thousand per ton. In order, to find solutions, the authors of this article used a research methodology based on factor analysis using the apparatus of economic and mathematical modeling of the problem of jet fuel delivery due to optimization of the logistics scheme of delivery to remote regions of the Arctic zone. By applying capability assessments correlation and regression analysis, estimation factors for the jet fuel supply chain optimization by optimizing the logistics scheme were carried out. As a result of the research and along with the proposed solutions of practical, technological and economic nature, a regression model is considered on the basis of which the most optimal options for the development of fuel supply of the Republic of Yakutia for air transport in the coming period can be suggested.

40-52 240
Abstract

The article addresses the issues of judicious choice of the most efficient aircraft for regional aviation of Russia for the purpose of eliminating transport discrimination of the population of the Russian Federation regions in terms of local traffic. Due to the high financial costs, the development of regional aviation is viable only in those constituent entities of the Russian Federation where the development of low-cost ground transportation is not feasible: most of these Russian Federation regions are attributed to the remote territories of the North-Western, Ural, Siberian and Far Eastern Federal Districts of Russia, therefore, this concern may affect the perspectives of up to 14 million people. The problem of minimizing the total costs to develop an advanced air transport system of local transportation (including airport infrastructure costs) is considered by selecting a well-targeted fleet of operated aircraft, taking into consideration the requirements for the quality of passenger service. The maximum local travel time is regarded as a quality criterion of local transportation. The calculation results for three- and four-type aircraft fleets are given. It is shown that the use of modern high-technology aircraft similar to the Pilatus PC-12NG allows us to reduce the level of transport discrimination almost to zero values, including sufficiently strict restrictions regarding the maximum local travel time of “2 hours”. At the same time, the increase of cruising speed up to more than 400 km/h is relevant specifically for aircraft with a capacity of no more than 9 passengers. For larger aircraft (type L-410), the issue of increasing speed is rather minor, since these aircraft are operated on flight distances of no more than 800 km. Concurrently, the total fleet of air transport vehicles in service amounts to 250–300 aerial vehicles. The obtained results can be used to specify the requirements for the advanced aircraft of local airlines.

53-61 263
Abstract

The development of modern gas turbine engineering imposes increasingly high requirements for the properties of the alloys used, associated with an increase in gas temperature before the turbine. However, the applicable nickel alloys have low heat resistance at high temperatures. The solution to this problem is achieved through the joint use of a heat-resistant alloy that takes loads at high temperatures, and the application of protective coatings to ensure heat resistance. The coating and the heat-resistant alloy form a complex system. Each component of the system performs the primary and secondary functions in the operation, and the system must meet operational requirements. The choice of the applied coating and its application technology are quite complicated, since its structure and thickness depend on many factors, in particular, on the composition of the original components, temperature, and time parameters of its application, etc. This affects the performance of the formed coating under operating conditions. In recent years, slip coating methods specifically formed from aqueous suspensions have been successfully developed abroad and in our country. This method is technically simple and economical. The quality of the coating formed from the aqueous suspension is determined by the percentage of the suspension composition, its rheological and physical properties, compliance with the technology of its application and processing of parts. In order to understand the mechanism of coating formation from the aqueous suspension, it is necessary to imagine the effect of the suspension parameters on the coating properties. The article presents the results of the study carried out by the computational method of the influence of the aqueous suspension parameters on the quality of the coating obtained. The dependence of the coating thickness on the particle sizes of the powders introduced into the suspension is shown. Calculations of the density and thickness of the obtainable coating from the ratio of the solid and liquid phases of the aqueous suspension are presented. It is indicated that in a real suspension, the influence of the aqueous suspension parameters on the coating parameters being formed is more complex than when performing calculations. This is primarily associated with the fact that in a real suspension there are powder particles of various diameters, in particular aluminum. In addition, the interaction of orthophosphoric acid with the introduced oxides of aluminum, silicon, etc., having molecular dispersion, their chemical interaction complicates considering all these factors in calculations. However, the obtained results of the study allow us to assess the influence of the aqueous suspension composition parameters on the technological and service properties of the obtainable coating obtained by the slip method from this suspension.

62-76 427
Abstract

Operators of unmanned aircraft systems (UAS), performing aeronautical work in accordance with the certification requirements of the Federal Aviation Regulations, are obliged to have a Flight Safety Management System (FSMS), the critical element of which is risk management. The utilization of the risk assessment methods and the development of corrective actions, used in manned aviation, is problematic due to the UAS operational characteristics. The article presents the FSMS methodology for UAS of category B (special category) based on the developments of JARUS group, established with EASA, to address the unmanned aviation operation issues. The proposed methodology integrates the SORA method provisions, developed by JARUS, and comprised into seven documents, into the unified logically related system with consideration to the specific traits of the Russian Federation Aviation legislation and the terminology adopted in the Russian Federation civil aviation. The key problem of assessing the expected effectiveness of risk management actions in the JARUS methodological guidelines does not have a complete solution.

The article proposes to solve the problem using professional evaluation by means of the hierarchy analysis method of the fuzzy set theory. This allows us to reasonably build the hierarchy of actions according to their impact on risk mitigation and to classify them into three categories. Such a classification is imperative to evaluate the applicability of actions depending on the amount of total risk. Although the UAS operation of category B is supposed to be performed in the segregated airspace, the methodology takes into consideration not only the risks of collision with objects on the ground but also mid-air collision risks with manned aircraft, since it is usually impractical to create the “ideal” segregated airspace. The proposed methodology can be utilized in the long view when developing risk management practices of UAS operation of category C in open skies.

MECHANICAL ENGINEERING

77-90 291
Abstract

Due to a steady extension of the flight envelope of modern agile combat aircraft, with the growing requirements for state tests, it is increasingly necessary to study the entire flight envelope and specifically, to determine the main performance data of individual maneuvers. Currently, state tests are based on a flight full-scale experiment, which is cost-ineffective in terms of cost, duration, and limit lines of the flight envelope. The accelerating trends to update state tests are semirealistic simulation and complex simulation modeling. The article presents the various techniques to determine main performance data of a three-dimensional maneuver split-S, which include the calculation method, semirealistic simulation, and simulation modeling. The calculation method is understood as calculation formulas expressed from the system of equations for motion of the aircraft mass center. Semirealistic simulation was carried out using a flight-simulation stand by operator pilots. Simulation modeling was conducted using a complex simulation model of an aircraft, consisting of a pilot’s control actions model based on fuzzy logic. The article provides the description, advantages and disadvantages, comparison of the results of each of the techniques. The calculation method, despite its efficiency, is the most inaccurate due to the complexity and inability to define the average flight parameters. Additionally, this method does not take into consideration such factors as the aircraft flight configuration, atmospheric disturbances, the pilot’s command profile, the logic of the permissible flight envelope limiter operation. The results of semirealistic simulation showed that this method is more accurate than the calculation one, but complex and time consuming in terms of the organization and execution of experiments. The analysis of the study illustrated that the most appropriate way to determine main performance data of split-S is simulation modeling on a complex simulation model of the aircraft, because the given method considerably saves financial and time resources used on state flight tests.



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ISSN 2079-0619 (Print)
ISSN 2542-0119 (Online)