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  Subjects -> AERONAUTICS AND SPACE FLIGHT (Total: 124 journals)
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Journal of Aerospace Technology and Management
Journal Prestige (SJR): 0.204
Citation Impact (citeScore): 1
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  This is an Open Access Journal Open Access journal
ISSN (Print) 1948-9648 - ISSN (Online) 2175-9146
Published by SciELO Homepage  [688 journals]
  • Presentation

    • Authors: Donizeti de Andrade, Joana Ramos Ribeiro, Eric Tchouamou Njoya
      Abstract: In the first three decades of the 21st century, the world’s society has realized the influence and importance of safety and security as the foundations of sustainable development. Moreover, recent events and developments, especially the coronavirus SARS-CoV-2 pandemic and the continual development of technology and global economic uncertainty, have indeed sharpened the problem of, among others, food safety and security, legal safety, land, and cyber security. The aviation industry is not immune to these developments, being inherently linked to all these safety and security dimensions. Thus, security and flight safety are of key strategic importance to the aviation industry, as accidents have the potential to affect customer choice and can severely impact an airline’s business viability. For this reason, continual improvements are central to the growth and sustainability of the industry.
      PubDate: 2022-11-25
  • Analysis of the Organization Designation Authorization in Aircraft
           Certification: Differences to the Brazilian and European Approaches

    • Authors: Bernardo Bacila Winkeler , Donizeti de Andrade, Marcus Vinicius Ramalho de Oliveira
      Abstract: This paper aims the identification of the Organization Designation Authorization (ODA) regulatory approaches adopted by the United States, using the Boeing 737 MAX 8 certification process as a basis, by revising the ODA’s certification role and what can be enhanced on the ODA program, considering the data from the Federal Aviation Administration (FAA), the U.S. Department of Transportation, AND the Office of Inspector General (OIG), and comparing them to the regulatory basis in Europe and in Brazil. An assessment of undue pressure on ODA Unit members and other aspects, such as conflicting restraints, analysing their consequences and roles for the process’ safety, is presented, as well as a comparison with the independent design assurance system adopted by the other two agencies. Therefore, the discussion around the ODA’s aircraft certification processes highlights the ODA model drawbacks, and what can be learned from other models to improve it, so the industry and the society can fully benefit from this system.
      PubDate: 2022-11-25
  • Operational Requirements Analysis for Electric Vertical Takeoff and
           Landing Vehicle in the Brazilian Regulatory Framework

    • Authors: José Ricardo Agustinho, Carlos Alberto de Mattos Bento
      Abstract: Air passenger transport is expected to change, in the next years, the urban air mobility (UAM) environment. New technologies are enabling the introduction of a new concept of aircraft, referred to as electric vertical takeoff and landing vehicle (eVTOL), with vertical take-off and landing capability, distributed electric propulsion system and low noise level compared to helicopters. This article presents an analysis of the Brazilian Civil Aviation Regulations (RBAC) No. 91 and 135, which address the minimum requirements for commercial operations of commuter and on-demand public passenger transport with airplanes with up to 19 seats. The objective of this article is to identify the technical and regulatory barriers to initiating the eVTOL operation in Brazil and to validate the current operational air traffic rules. After the analysis of the operational requirements and the current Air Traffic Management (ATM) infrastructure for helicopter operation, the minimum required and recommended navigation, communication and surveillance equipment are identified, as well as the main operational limitations for the operation of this type of aircraft in transporting passengers. This analysis is just the beginning of a broader study and there are many challenges to support an increased eVTOL operations.
      PubDate: 2022-11-25
  • eVTOL Certification in FAA and EASA Performance-Based Regulation
           Environments: A Bird Strike Study-Case

    • Authors: Suzana Helena Silva Braga Cardoso, Marcus Vinicius Ramalho de Oliveira, José Rui Simons Godoy
      Abstract: Considering the new generation of air mobility vehicle that has been developed, the electric vertical take-off and landing (eVTOL) aircraft operation will become a reality in the next years. This paper studies the main concerns that can be pointed out due to the different certification approaches that the Federal Aviation Administration (FAA) and European Union Aviation Safety Agency (EASA) have been applying for this kind of aerial vehicle. The paper explores the 14 CFR Part 23-64 and CS-23-5 reorganization to demonstrate how these changes into the requirement structure will be important and influence the eVTOL certification basis construction. Based on the high probability of bird strike events that an eVTOL may face due to its altitude operation, a studycase for a bird strike certification using the known FAA and EASA approaches is performed, considering the current regulation presented into Part 23/CS-23, Part 27/CS-27, Part 29/CS-29 and SC-VTOL-01. The main differences concluded in this evaluation and possible risks and difficulties that an applicant will face during the process are then explored. A final comparison between a bird strike certification process that may be required by FAA and EASA is presented, as well as a recommendation based on the study
      PubDate: 2022-11-25
  • Modeling Resilience of Air Traffic Management Systems Based on Complex

    • Authors: Francisco Claudio Gomes Sampaio, Raimundo Nogueira Costa Filho, Marcelo Xavier Guterres
      Abstract: The air transport market has a strategic character, promotes economic and social development, and has a strong correlation with the level of economic activity. The Air Traffic Management (ATM) system plays an essential role in air transportation and can be characterized as a sociotechnical system that is too complex to research through classical approaches such as systems engineering. In this sense, the application of Complex Network Theory (CNT) analysis and modeling paradigms is driven by the need to accommodate the growth of air traffic within an already saturated ATM infrastructure. The present work describes the development of a resilience evaluation model of ATM systems based on CNT, its metrics and analysis tools. The model was applied to the Brazilian ATM system, demonstrating its usefulness in identifying the air traffic control (ATC) agencies that have the greatest influence on the network. The results also showed that the Brazilian ATM network is resilient to random failures; however, it is particularly vulnerable to targeted attacks to the ATC agencies with the highest centrality. The research findings can be applied to prioritize the deployment of systems and equipment that enhance the resilience and operability of the Brazilian ATM system.
      PubDate: 2022-11-25
  • Intelligence and Airport Security: A SWOT Analysis of the Brazilian

    • Authors: David Medeiros Oliveira, Donizete de Andrade, Arthur Maximus Monteiro
      Abstract: The Brazilian airport infrastructure arises under the government management, through a public company created especially for it: the Brazilian Airports Infrastructure Company (Infraero). This management model thrived until the early 2000s, when the concessions of Brazilian airports to the private sector started. Since the Brazilian Intelligence System (SISBIN) was created in 1999, Infraero has been under a federal government’s cabinet with a seat at the system. After the concessions’ processes started, though, some of the main airports in the country are not under SISBIN’s formal umbrella anymore. This paper uses a SWOT matrix to analyze the scenario that comes out after of the migration of the airport management to the private sector under the Intelligence activity’s scope.
      PubDate: 2022-11-25
  • Evaluation of the Human Harnesses used by Tactical Flight Officers in
           Brazilian Public Air Units

    • Authors: André Ricardo de Almeida Vilela, Donizeti de Andrade, Marcelo Guerrante Guimarães
      Abstract: This work evaluates the normative and legal compliance related to the human harnesses used by tactical flight officers in the institutional missions conducted by the Brazilian Public Air Units (UAPs), regulated by the Brazilian Civil Aviation Regulation (RBAC) no. 90. The study bases its analysis on the identification of regulatory obstructions that limit the performance of the Brazilian State, from the operational and aeronautical product certification standpoints, as well as on the demonstration of legal risks to the current operational context adopted by the units. The use of inappropriate human harnesses has shown to be a contributing factor to aviation occurrences and fatalities in Brazil. This research delivers a regulatory alternative with a view to greater operational flexibility, legal safeguards and increased safety for the UAPs and entities that employ air transportation as a tool for their institutional activities.
      PubDate: 2022-11-25
  • A Customized Data Model for an Integrated Process of Requirements and
           Configuration Management

    • Authors: Sérgio Ricardo de Freitas Oliveira , Guilherme Conceição Rocha, Donizeti de Andrade
      Abstract: This work aims to propose a customized, open-source data model for supporting an integrated process of Requirements and Configuration Management that allows for keeping track of which requirement originated each part, subsystem and system — and vice versa—, over their entire life cycle. That model might prospectively contribute to the processes of Aeronautical Engineering design and Continued Airworthiness in organizations that do not want either to invest in complex existing commercial, proprietary software packages or to train their professionals for that purpose. The complete source code of the model is provided in Python and SQL languages.
      PubDate: 2022-11-25
  • BowTie Methodology for the Risk Management of the Spin Maneuver During
           Flight Training in Brazil

    • Authors: Ivan Resende Leitão, Donizeti de Andrade, Marcelo Soares Leão, Pedro Allan Giglio Sarkis
      Abstract: This paper aims to present the BowTie methodology as a practical tool for the Risk Management of the spin maneuver during flight instruction, identifying hazards, controls and consequences related to the loss of control in-flight (LOC-I). Exploratory research was carried out regarding its objectives, through a literature review. Initially, a comparison is made between the Brazilian and international training programs, then the particularities of this training in Brazil was analyzed. Finally, a step-by-step construction of a BowTie developed is presented to reduce LOC-I occurrences during spin training.
      PubDate: 2022-11-25
  • Analysis of Automation Mode Confusion with Brazilian Airline Pilots

    • Authors: Leonardo Maximiliano Albano, José Alexandre Tavares Guerreiro Fregnani, Donizeti de Andrade
      Abstract: Automation is an important feature in-flight operations and its implementation in aviation has brought numerous benefits, such as reducing the workload and optimizing operations. However, there are difficulties in crew interaction with automation, such as autopilot mode confusion. To expose which mode confusions are usually prevalent and recurrent with Brazilian pilots, a survey-style questionnaire was administered to airline pilots. The survey results, answered by 145 pilots, reveal that the average frequency of mode confusion is 2.01 ± 0.40 occurrences per year and less experienced pilots are more likely to experience the phenomenon. This research points out that the prevalence of the phenomenon of mode confusion occurs in the final stages of flight, the vertical navigation (VNAV) modes being the most complex and confusing to pilots. The research also presents the main causes of mode confusion, as perceived by the pilots, their consequences, and mitigating measures. Data collected in this study can be used in future studies and by airlines to develop mitigating actions to manage the risk of mode confusion.
      PubDate: 2022-11-25
  • Comparison between Performance Requirements for Certification and
           Performance Requirements for Operation of Transport Category Rotorcraft

    • Authors: Clementino Rodrigues Veras Neto , Donizeti de Andrade
      Abstract: In order to achieve aviation safety, integrity of two pillars is essential: product and operations. Regarding product integrity of transport category rotorcraft, its requirements are established in USA by the Federal Aviation Administration (FAA) Part 29, as Categories A and B. Regarding rotorcraft operations, the International Civil Aviation Organization (ICAO) has established Performance Classes 1, 2 and 3 in its Annex 6 Part III, determining they shall occur under a Code of Performance established by the State of the Operator. Should operations neglect certification requirements, particularly certification performance operating limitations, the intended protection (i.e., aviation safety) remains, therefore, unassured. This is possibly the case with offshore operations, pushed by a supposed commercial viability (increased payload) for oil and gas industry. Aiming to clarify it, the authors critically peruse through an exploratory and qualitative research of historical and bibliographic documentation of both rotorcraft certification and operation issued by ICAO and FAA and, in doing so, enhance understanding of the overlaps and complementarity (or otherwise) of certification and operational performance requirements for transport category rotorcraft.
      PubDate: 2022-11-25
  • Conceptual Models of Startle, Surprise and Automation Bias Analyzed
           Through Recent Aviation Accident Reports

    • Authors: Karen Cristiane Gardini, Fernando Holanda Chiavelli, José Ricardo Silva Scarpari, Donizeti de Andrade
      Abstract: This work aims to analyze three conceptual models of startle, surprise and automation bias found in the literature: Conceptual Model of Startle and Surprise, Integrated Model of Complacency, and Automation Bias and Conceptual Model of Threat, Appraisal and Information Processing. Afterwards, an analysis of accidents reports of Lion Air 43, Lion Air 610 (737-MAX), Emirates 407 and TAM 3054 is carried out using the selected conceptual models. The aim is to deepen the knowledge about startle, surprise and automation bias by means of an analysis of how they are found in recent accidents, disseminate the subject to the aeronautical community and reinforce their importance for aviation safety.
      PubDate: 2022-11-25
  • The Transformation of Airports into Hubs and the Lessons for Fortaleza

    • Authors: Henrique Jorge Javi de Sousa , Donizeti de Andrade, Hugo Santana de Figueiredo Junior
      Abstract: Civil aviation is experiencing consistent long-term growth, encouraging the formation of airport conglomerates offering multiple connections (hubs). These hubs have the power to promote development, but also to synchronously influence the structure of the cities that host them. However, there is little research on the long-term evolution of these hubs related to socioeconomic development and to city-airfield interaction. This study aims to identify the characteristics of the respective cities that most impact the transformation of airports into connection centers or international hubs, and to describe the initiatives and conditions that can generate sustainability in the city-airport relationship. A comparative, nonsequential multicase study is used, and a scenario for the evolution of world air transport is built from secondary sources. The results show that cities that have included the aeronautics value chain in their planning evolve faster and bring more benefits to the consolidation and growth of their aeronautical structures, as well as to the development of the cities themselves. The integration of urban planning to the planning of the local aeronautical chain could help airports such as the Fortaleza Airport, in Ceará, Brazil to sustainably evolve into an international hub.
      PubDate: 2022-11-25
  • Evaluation of Strategies for Aeronautical Value Chains and the
           Implications to the State of Ceará, Brazil

    • Authors: Henrique Halisson Evangelista Gomes, Donizeti de Andrade, Lígia Maria Soto Urbina, Hugo Santana de Figueiredo Junior
      Abstract: Several regions of the world seek to participate in the aeronautical value chain, aiming at employment quality and absorption of technologies. This upgrading movement is studied in industries usually employing concepts and methodologies developed for companies or isolated agglomerations. However, no comparative studies of aeronautical chains’ strategies in emerging countries have been identified. This paper evaluates strategies adopted by segments of the aeronautical value chain and, complementarily, presents the implications for the Brazilian state of Ceará. To achieve this objective, the Value Chain Structure-Conduct-Performance (SCP) framework, recently developed for evaluating value chain strategies is applied, by means of a qualitative comparative analysis of segments located in selected territories outside Europe and the United States. Celebration of international agreements and improvements in infrastructure are identified as structural elements of influence in the determination of strategies aimed at creating jobs in the chain. The aeronautical value chain in the state of Ceará has an attractive structure to services. The study also suggests that the use of Value Chain SCP framework can contribute to the analysis of technology-intensive value chains and, more specifically, provide recommendations on strategies for segments of the aeronautical value chain located in emerging countries.
      PubDate: 2022-11-25
  • Skills Assessment Criteria for Aircraft Maintenance Technician in the
           Context of Industrial Revolution 4.0

    • Authors: T Nanthakumaran Thulasy, Puteri Nor Ellyza Nohuddin, Istas Fahrurrazi Nusyirwan, Noorlizawati Abd Rahim, Astuty Amrin, Stephanie Chua
      Abstract: Professional certification is required for aircraft maintenance technicians in order to undertake sophisticated maintenance tasks that need a wide set of skills and competencies. Due to the increasing demand for workforce preparedness for Industrial Revolution 4.0, numerous publications stress only a subset of aircraft maintenance skills criteria in their skills assessment curriculum. The purpose of this paper is to review previous research publications on skill and competency evaluation in the aircraft maintenance industry in order to develop a comprehensive set of skill and competency assessment criteria through a systematic review of the literature. It applies the PRISMA approach in selecting and evaluating the included articles. The papers were retrieved from five journal databases using a set of Boolean search terms related. The filtered fifteen articles are systematically reviewed for talent evaluation criteria applicable to the aircraft maintenance work scope in order to deal with the Industrial Revolution 4.0 (IR4.0). Certain articles concentrate on a subset of assessment criteria for enhancing and tracking critical skills assessment criteria for the aircraft maintenance workforce, rather than on IR4.0 skill standards specifically. This paper summarizes seven skill criteria gathered in order to develop a comprehensive skill assessment framework for aircraft maintenance workforce.
      PubDate: 2022-11-24
  • Path Tracing Method to Evaluate the Signature Reliability Function of a
           Complex System

    • Authors: Emad Kareem Mutar
      Abstract: This paper aims to compute the efficiency of a complex communication system (double-bridge). In this model, which applies the Path Tracing Method for evaluating the reliability function of the complex communication system, the process of analyzing the system’s reliability has been used to lower the failure rate of the complex system in order to optimize its competence. The illustrative system is subdivided into nine minimal paths that are arranged in series-parallel combinations. Using the Path Tracing Method, the system’s reliability, minimal signature, tail signature, signature, Barlow–Proschan index, expected time, expected cost, and sensitivity were determined. The results assist in the creation of a probabilistic approach to analyze and probabilistic method to evaluate the system signature and reliability in a way that is highly useful.
      PubDate: 2022-10-09
  • Static Firing Tests of Solid Propellant Rocket Motors: Uncertainty Levels
           of Thrust Measurements

    • Authors: Fernando Augusto Catalano Fernandes , Carlos d’Andrade Souto , Rogerio Pirk
      Abstract: Static firing tests of solid propelled rocket motors (SRMs) are important tests in aerospace industry during the development of new motors as well as to assure the quality of a motor batch. This type of test allows the operator to obtain the measured “thrust versus time of burning” graphic yielded by the motor during burning to verify whether the motor performance matches the project requirements. Laboratory Quality Certificates and good measurement practices make necessary the evaluation of the typical uncertainty of these test results, which demand a wide number of instruments, called measurement chain. This work aims to present the uncertainty levels expressed to the thrust values gathered during a SRM static firing test for two differently configured measurement chains. In order to estimate the uncertainty of a complete measurement chain, the theories of expanded and combined uncertainties are employed. It was possible to verify that in the analyzed case the use of signal amplifiers increased the measurement uncertainty of the chain.
      PubDate: 2022-09-12
  • Safety Analysis of GNSS Parallel Runway Approach Operation at Guarulhos
           International Airport

    • Authors: Rodrigo Gentil Rodrigues, Jonas Bianchini Fulindi, Diogo Bertolini Profeta de Oliveira, Alison de Oliveira Moraes, Leonardo Marini-Pereira
      Abstract: The air traffic environment is a complex system that involves several players. Between the air navigation service provider (ANPS) and the final client, many different organizations act with different purposes but are strongly interfaced. Changes and modifications in terms of technology, predefined process, or personnel are constantly needed, requiring coordination among the stakeholders. However, due to the high level of interaction between the players, any change in a complex system like the air traffic environment requires risk management. This paper demonstrates the suitability and advantages of the System-Theoretic Accident Model and Processes/Systems-Theoretic Process Analysis (STAMP/STPA) method to be applied to the risk assessment of an operational air traffic modification. The method, which had never been used on an air traffic problem in Brazil before, was applied considering the implementation of segregated simultaneous operation at the Guarulhos International Airport. The results were proven to be effective in terms of deriving useful safety requirements. From such demonstration, STAMP/STPA can be considered as a feasible alternative to the brainstorming method currently applied for risk assessment and generation of safety requirements regarding modifications in the structure of the air traffic services (ATS) in Brazil.
      PubDate: 2022-07-24
  • Evaluating an Aircraft Response to Disturbances Caused by Vibration
           Frequency of Wind Forces During Landing

    • Authors: Devinder Kumar Yadav, Perumal Kannan, Shuhaimi Mansor
      Abstract: Approach and landing phases take less than 4% of total flight time of a typical flight, but 36% of fatal aircraft accidents occur during this phase. Gust disturbances creating uncertainties during this phase are primary contributors to many unstabilized, high and fast approaches leading to catastrophic ending. This study analyses the effects of gust and resulting responses affecting the handling and flying characteristics of an aircraft during landing. A pilot-in-the-loop flight simulation during landing with the effect of gust was developed using Boeing B747-100 aircraft to analyze the problem. Elevator and throttle inputs through a joystick were used as control inputs to allow the pilot-in-the-loop to control the aircraft glide-path and speed during landing. It was found that the aircraft flight path during the descent is not affected, if the frequency of the gust is higher than the natural frequency of the aircraft, but maintaining the flight glide path becomes difficult for lower frequencies. Likewise, the vertical gust has more prominent effect than the horizontal gust. In both cases, the aircraft susceptibility to gust disturbances increases the pilot workload causing more difficulties for a landing.
      PubDate: 2022-07-23
  • Modeling and Analyzing the Free Vibration of Simply Supported Functionally
           Graded Beam

    • Authors: Raghad Azeez Neamah, Ameen Ahmed Nassar, Luay Sadiq Alansari
      Abstract: Euler, Timoshenko and high shear deformation theories to analyze the free vibration of the functionally graded (FG) beam were developed. The mechanical properties of this beam were assumed to differ in thickness direction according to the model of a power-law distribution. The principle of Hamilton was used to find equations of motion. For free vibration, the analytical solution of these equations was presented using the Navier method. The effect of power index, aspect ratio, modulus ratio, and deformation theories on dimensionless frequency were studied numerically by Ansys software and analytically according to different beam theories using the Fortran program. The obtained results from these programs were compared with each other and with some previous research. Results showed an excellent agreement with the previous research. The numerical and analytical results showed that the use of this new FG beam model especially based on first and high shear deformation theories leads to the reduction of dimensionless frequency. It may be concluded that, the including of shear’s effect leads to a decrease in the dimensionless frequency. From the modeling and analysis of this model, it is possible to know what is the appropriate design for this FG beam model to reduce the vibration.
      PubDate: 2022-07-23
  • Validation of a Flying Competence Scale for Aircraft Pilots

    • Authors: Harold Toring, Ranel Merino Benatiro, Nonita Legaspi, Maria Luz Cahayagan, Ronaldo Felix, Adriane Adaptar, Sylvester Tan Cortes
      Abstract: This study aims to validate a scale that evaluates the flying competence of aircraft pilots. The scale was developed by pilots in an aerospace university and was approved by the Civil Aviation Authority of the Philippines. To do so, the scale was administered to 288 pilots holding different levels of licenses. The data obtained were subjected to Exploratory Factor Analysis (EFA) and created a three-factor model. The factors are set of flying skills named as instrument flight (Factor 1), basic attitude flying (Factor 2), and instrument landing system (Factor 3). The model was confirmed utilizing the resulting values of five goodness of fit indices (GFIs) generated by the Confirmatory Factor Analysis (CFA). Only comparative fit index, Tucker–Lewis index, and Standardized Root Mean Squared Residual resulted to values falling within the thresholds. These three GFIs are already adequate to confirm that the model is relatively good fit. The standardized factor loadings (SFLs) and composite reliability (CR) were also excellent, thus, establishing convergent validity. Also, the estimated average variance extracted and Cronbach’s alpha of all factors provided evidence of discriminant validity and reliability, respectively. In conclusion, this scale is valid and reliable to evaluate the pilot’s performance in flying an aircraft.
      PubDate: 2022-06-30
  • The Importance of Frequent Flyer Programs: An In-depth Analysis

    • Authors: Chayapoj Lee-Anant
      Abstract: This paper discusses the important roles of frequent flyer programs (FFPs) in the airline industry with an emphasis on FFPs as a tool for airline business development, a customer relationship management (CRM) tool, and an airline tool of highest return of investment among CRM initiatives. An FFP is a sort of loyalty program sponsored by an airline or a group of airlines that rewards regular passengers with extras and prizes to make flying with the airlines convenient. Thus, advantages and disadvantages of FFPs between airline businesses and passengers are critically discussed. The paper examined existing and recent literature reviews with some add-on case studies. Interestingly, FFPs can be both push and pull factors for airline competitiveness enhancement, analytically reviewed. All discussions presented has revealed that FFPs can be a forceful tool for creating airline competitiveness, depending on how the airline manage it professionally or not. It can be summed that if the airlines manage their FFPs effectively, they can retain their existing passengers and be able to keep the market share. Hence, the airline competitors cannot effortlessly enter to the selected market.
      PubDate: 2022-04-22
  • Design of the Missile Attitude Controller Based on the Active Disturbance
           Rejection Control

    • Authors: Shanzhong Liu, Mengqi Xue, Yaolong Qiu, Xingyu Zhou, Qingxiu Zhao
      Abstract: Targeting at the stable tracking control problem of the interceptor missile’s flight attitude in the terminal guidance phase, the nonlinear mathematical model of missile attitude is used as the research object, in which the coupling among the channels is considered. The control strategies of Proportion Differentiation (PD) control, nonlinear and linear active disturbance rejection control are studied. Firstly, the expanded state observer is designed to estimate the total disturbance information in real time, and the error feedback controller is designed to provide disturbance compensation, so that the original second-order nonlinear system is decoupled into the canonical form of cascade integrators to realize the stable tracking control of the missile attitude. Secondly, the three-channel coupling closed-loop control system model is established, and under the influence of external disturbance and model parameter perturbation, the comparison between the three control methods is demonstrated by simulations. The simulation results show that these three methods can stabilize the missile attitude and track the reference input signal. Among them, the nonlinear active disturbance rejection control has the smallest overshoot, the strongest antiinterference ability, and better robustness.
      PubDate: 2022-04-22
  • Geometric Analysis of Small Wind Turbine Blades Manufactured by Additive

    • Authors: Heitor Andrade Porto, Carlos Alberto Fortulan, Arthur José Vieira Porto, Roberto Hideaki Tsunaki
      Abstract: One of the many benefits of additive manufacturing (AM) is to produce parts ready to assemble and use, a concept called direct digital manufacturing (DDM). This, besides the ease of manufacturing complexes geometries, creates a potential for applying the AM technology for producing small wind turbines (SWT) blades. Small wind turbines have an increasing role in the worldwide energy matrix, which can be built up by developing site-optimized and customized turbines. Customizing SWT can increase the energy harvesting potential of such machines; however, it requires flexible manufacturing procedures. The blade’s geometric complexity and flexible manufacturing are features that can benefit from the potentials of AM. This work analyses the final geometry of SWT blades manufactured by AM, assessing the scope of DDM in the SWT field. The parts length is 225 mm, the blades were manufactured by the Fused Deposition Modeling (FDM) method using a Dimension Elite machine produced by Stratasys. The geometric evaluation was performed using a CROMA coordinate measuring machine. The measurements showed good results when compared to values adopted in several studies that investigated the effects of geometric disturbances on wind turbine blades. This work affirms that AM is a powerful technology for manufacturing SWT blades in a DDM scope.
      PubDate: 2022-04-22
  • An Illustrative Evaluation of External Factors That Affect Performance of
           an Airline

    • Authors: Devinder Kumar Yadav, Maryil O Goriet
      Abstract: Since the beginning of globalisation and open sky policies, airlines experience intense competition, and their performance get affected by many external factors in addition to internal issues. Fuel price fluctuation, aircraft maintenance, labour and aircraft technical operations cost are primary factors that significantly drain the budget of an airline while exerting strong impact on its operational performance. However, this study focused on effects of external factors, such as political, economic and legal mandates on an airline performance. Therefore, relationships between these factors and airline operational performance are identified and analysed in this paper. Kenya Airways has been chosen as a representative airline for this study. Nevertheless, examples from other airlines are also included for the analysis. Data for this research were collected though a descriptive survey designed according to a qualitative mixed approach. Consequently, focused interviews and questionnaires were used, and reliability of obtained results was checked using Cronbach’s alpha method. The results indicate strong positive correlations between the external factors and performance of an airline. This study therefore confirms that performance of an airline can be influence by market driven fluctuations or intentionally altered external factors discussed in this project.
      PubDate: 2022-03-30
  • Comparative Study of Coaxial Main Rotor Aerodynamics at Forward Flight
           Based on Free Wake Model and Unsteady Reynolds- Averaged Navier–Stokes

    • Authors: Sergey Gennadievich Konstantinov, Yuri Mikhailovich Ignatkin, Pavel Viacheslavovich Makeev, Alexander Ivanovich Shomov, Sergey Olegovich Nikitin
      Abstract: This paper is dedicated to the numerical modeling of the aerodynamic characteristics of the full-scale coaxial main rotor. The modes of forward flight in the range of values V = 30−60 m∙s–1 (108−216 km∙h–1) have been under consideration. The simulation has been performed with the usage of two computational fluid dynamics (CFD) approaches: the free wake model (FWM) developed by the authors and the unsteady Reynolds-averaged Navier–Stokes (URANS) equations method based on the Ansys Fluent software. The coefficients of rotor thrust and torque, vortex wake shapes and induced velocity fields have been obtained and analyzed. The FWM and the URANS modeling data match satisfactorily. The FWM demonstrates a significant advantage in computing time and resources costs with sufficient accuracy in resulting rotor’s basic aerodynamic characteristics. That’s why it seems appropriate to use the FWM for preliminary simulations, taking into account before using the high time and resource intensive the URANS method for comprehensive investigation of coaxial rotor aerodynamics at flight modes.
      PubDate: 2022-03-15
  • Comparative Analysis of the Aeronautical Certification Process Against
           Nonionizing Radiation and the Management Proposal for Ionizing Radiation

    • Authors: Marcelo Tadeu Ferreira, Claudio Antonio Federico
      Abstract: Today, the certification process for onboard electro-electronic systems against nonionizing radiation can be considered mature and independent, having its own set of requirements. In turn, the current proposal for this process with regard to ionizing radiation is relatively recent and is in the process of improvement and discussion by industry and regulatory bodies, and presents important differences in approach. In this work these two processes are presented comparatively in detail, pointing out similarities and differences in order to contribute to this ongoing discussion, which should, in the medium term, result in regulation for the effects of ionizing radiation.
      PubDate: 2022-03-15
  • A Proposal of Optical Navigation for Deep Space Mission ASTER to Explore
           NEA 2001-SN263

    • Authors: Antonio Gil Vicente de Brum, Carolina Schuindt
      Abstract: In addition to radio navigation, optical navigation has been used successfully in deep-space missions since the launch of the Voyager spacecraft, in the 1970s. In the 1990s, the NASA’s Deep Space-1 mission successfully tested an autonomous optical navigation system which allowed great reduction in mission costs, and maximized scientific results. The ASTER mission, the first Brazilian deep space mission, shall count on the support of optical navigation for all its phases. The platform of the probe is the Russian Pilgrim spacecraft developed by the Russian Space Research Institute for the Finnish-Russian mission to Mars (MetNet). As such, besides the scientific camera on board (which may also be used for navigation purposes), the probe will also dispose of a navigation camera (NAVCAM). This study is related to the formulation of a general proposal of optical navigation, that can be used in the ASTER mission, which takes into account the equipment available on board, especially the NAVCAM, along with tracking software suitable for the conduction of optical navigation. The description of an appropriate navigation algorithm together with its successful application to simulated and real images (from NASA’s New Horizons mission) is carried out.
      PubDate: 2022-03-15
  • The GNSS NavAer INCT Project Overview and Main Results

    • Authors: João Francisco Galera Monico, Eurico Rodrigues de Paula, Alison de Oliveira Moraes, Emanoel Costa, Milton Hirokazu Shimabukuro, Daniele Marra Barroca Alves, Jonas Rodrigues De Souza, Paulo De Oliveira Camargo, Fabricio Dos Santos Prol, Bruno César Vani, Vinicius Stuani Amadeo Pereira, Paulo Sergio de Oliveira Junior, Italo Tsuchiya, Claudinei Rodrigues Aguiar
      Abstract: Air navigation is increasingly dependent on the use of Global Navigation Satellite Systems (GNSS). It allows the determination of the aircraft’s position in all phases of the flight and brings many advantages. Although GNSS navigation results in gains, the radio signals from these systems are strongly influenced by the ionospheric environment. It introduces errors that can affect the accuracy, integrity, availability and continuity requirements established by the International Civil Aviation Organization (ICAO). The ionospheric layer has different behaviors depending on the latitude, time of day, season of the year, geomagnetic activity and solar cycle. Since Brazil is located in a region of low latitudes, it experiences a series of unique challenges when compared to regions of mid-latitudes. For this reason, the application of GNSS-based technologies in aviation over the Brazilian territory requires an in-depth assessment of the ionosphere effects. Therefore, the Instituto Nacional de Ciência e Tecnologia (INCT) named GNSS Technology for Supporting Air Navigation was formed in 2017 to better assess the ionosphere impacts and assist government agencies and companies in the development of safe air navigation procedures over Brazil in a near future. This paper presents the most relevant advances achieved so far within this multidisciplinary project that involves Brazilian research centers and universities.
      PubDate: 2022-03-15
  • Evaluation of Conversion Coatings Without Hexavalent Chromium for
           Aerospace and Defense Applications

    • Authors: Gregory Morose, David Pinsky, Chandler Humphrey, Kent DeFranco
      Abstract: Conversion coatings containing hexavalent chromium are currently used in aerospace and defense manufacturing on various aluminum alloys to provide corrosion protection and enhanced adhesion of subsequent coatings. However, hexavalent chromium is toxic to humans with negative health effects from acute and chronic exposure. Regulatory mandates have accelerated a global effort to replace hexavalent chromium-containing materials because of their toxicity. A consortium was established to evaluate safer conversion coating materials, including the chemical processing of the surfaces prior to applying the conversion coatings. Four conversion coatings without hexavalent chromium were compared against a hexavalent chromium-based conversion coating for the following tests: coating weight, electrical contact resistance, paint adhesion, bare and painted neutral salt fog corrosion tests, painted SO2 salt fog corrosion test, and painted outdoor beachfront corrosion test. The test results for the four conversion coatings without hexavalent chromium were encouraging since several candidates exceeded some of the specification requirements or consortium expectations. In particular, the Socosurf TCS/PACS conversion coating performed well in the coating weight, electrical contact resistance, paint adhesion, and corrosion tests. The results of this evaluation provide significant progress toward providing a replacement material for a traditionally hexavalent chromium material application on aluminum.
      PubDate: 2022-02-23
  • Quantification of the Lifetime and Reliability of Dual-Mode Ion Thrusters

    • Authors: Xueer Zhang, Tianping Zhang, Detian Li
      Abstract: An approach to quantify the lifetime and reliability of dual-mode ion thruster is presented based on coupling analyses of thruster failure modes, throttle levels, life models, input uncertainties, and throttle profiles. This approach involves lifetime characterization based on each failure mode, a conservative life margin assessment followed by a failure mode reduction and a quantification of life margins and uncertainties which gives a further reduction of the failure modes, Weibull fitting of the sampled lifetimes based on each of the remained failure modes to obtain their reliability functions, and derivation of a combined reliability function according to the throttle profile. The results for LIPS-200E completing a 13 kh mission show that the lifetime distribution and mission reliability strongly depend on the throttle profile.
      PubDate: 2022-02-21
  • Reduction of the Pressurization System Final Mass for a Modern Rocket

    • Authors: Yurii Mitikov, Olexiy Shynkarenko
      Abstract: The work focuses on optimizing the pressurization system’s operating performance for a fuel tank of a turbo-pumped liquid propellant rocket engine. This system is the most complex and expensive in a medium-size launch vehicle, after the engine. A new patented methodology of reducing the final mass of a rocket stage is proposed, studied, and validated. The application of the proposed method is efficient at the end of the engine operation sequence during the throttling regime. The calculation method of the helium excess in the high-pressure cylinders uses the model of the real gas. It also involves empirical relations describing nonstationary heat and mass transfer in the system. As an innovative technical solution, the authors propose to estimate excess gas discharge from tanks and cylinders after the engine’s last throttling. The practical application of the research allows saving tenths of kilograms of a payload with the implementation of simple modification in the launcher control program. The research results demonstrated the effectiveness of the methodology on the example of the RD-171 fuel tank pressurization system.
      PubDate: 2022-01-27
  • Atmospheric Flow at Alcantara Launch Center

    • Authors: Karine Klippel, Elisa Valentim Goulart, Gilberto Fisch, Bruno Furieri, Cayo Prado Fernandes Francisco, Neyval Costa Reis Junior
      Abstract: The Alcantara Launch Center (ALC) is the main Brazilian access to space. It is positioned over a complex terrain, and it has some important buildings for assembling, integration and launching activities, such as the Mobile Integration Tower. Being in a region of prevalent trade winds, the flow interaction between the complex terrain and the buildings can affect the safety of operations on the platform, and the dispersion of toxic gases emitted during the launching. The main objective of this work was to study the influence of topography and buildings on the atmospheric flow of ALC using computational fluid dynamics (CFD) techniques. Three geometries were considered: simplified terrain (case 1), smooth complex terrain(case 2), and roughness complex terrain (case 3). The flow conditions over ALC were simulated using the ANSYS Fluent 19.0 CFD commercial code. The numerical simulations used a realizable κ-ε to model turbulence effects and the results presented a good agreement with the in-situ field measurements for the most complex geometry (case 3). The topography clearly influences the flow pattern at ALC, with the cliff influence over the wind being the major cause for establishing the flow patterns.
      PubDate: 2022-01-27
  • Investigation on Mechanical Properties of Carbon Fiber Composite Using FEM
           for Leaf Spring Applications

    • Authors: Ramesh Kumar Rajamanickam, Rajesh Durvasulu, Sundarraj Moorthi
      Abstract: Nowadays, many industries are shown interest in the hybrid composites, natural fibers, and reinforced materials due to reduction of the weight. The reason is that it will not affect environmental conditions. This experimental investigation identified the mechanical properties of hybrid composites. The hybrid composite materials are extensively used by E-glass/epoxy, carbon, and titanium alloy. Composites have good strength and less weight. The highest challenge of the automobile industry is to replace the steel leaf spring instead of the composite leaf spring. The composite structures have been providing better corrosion resistance. The conventional leaf spring experimental results were compared to analytical results of composite leaf spring. The design, simulation, and maximum stresses were done with the help of Ansys Workbench 15. Ansys Workbench materials are selected by titanium alloy, epoxy glass, aluminum alloy, and epoxy carbon. The design parameters were selected and analyzed to compare stress, deformation, elastic strain, and weight of the composite leaf spring as compared to conventional steel leaf spring. Deflection results were identified in the mechanical properties of the leaf spring. It should absorb shock loads and vertical vibrations due to road abnormalities. The composite experimental samples were analyzed using scanning electron microscopy
      PubDate: 2022-01-27
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