Maintenance Technicians Research Articles

Sensor-less Brushed DC Motor Speed Control with Intelligent Controllers

A Direct Current (DC) Motor is usually supposed to be operated at a desired speed even if the load on the shaft is exposed to changes. One of its applications is in automatic door controllers like elevator automatic door drivers. Initially, to achieve this aim, a closed loop control can be applied. The speed feedback is usually prepared by a sensor (encoder or tachometer) coupled to the motor shaft. Most of these sensors do not always perform well, especially in elevator systems, where high levels of noise, physical tensions of the mobile car, and maintenance technicians walking on the car, make this environment too noisy. This Paper presents a new approach for precise closed loop control of the DC motor speed without a feedback sensor, while the output load is variable. The speed here is estimated by the Back EMF (BEMF) voltage obtained from the armature current. First, it is shown that a PID controller cannot control this process alone, and then intelligent controllers, Fuzzy Logic Controller (FLC) and Adaptive Neuro Fuzzy Inference Systems (ANFIS), assisting PID are applied to control this process. Finally, these controllers’ performance subjected to a variable mechanical load on the motor shaft are compared.

Off-stage Heroes: The Antecedents and Consequences of Job Passion among Civil Aviation Maintenance Crew

ABSTRACT Objective: The main goals of this study are to identify the possible factors that may affect the level of passion that aircraft technicians have for their job and how job passion may lead to safety motivation.Background: Aircraft maintenance technicians play an essential role in ensuring flight safety since they are obligated to carry out critical responsibilities related to maintaining flight devices. However, the significance and professionalism of civil aircraft technicians tend to be underestimated due to limited academic discussion of job-related issues. In practice, the particular job characteristics and working environment have led to various job demands and requirements for job resources, which may be related to the level of passion of the aircraft maintenance crews.Method: Structural equation modeling (SEM) was used to analyze the empirical data collected with the questionnaire survey. The sealable stamped addressed envelopes were attached to guarantee for the innominate approach, and a total of 411 usable samples was returned.Results: Significant relations found between work-family conflict, professional development and job passion in the expected directions, while non-significant results were presented between work-load, social support, and job passion. In addition, job passion significantly and positively related to air technicians’ safety motivation.Conclusion: Aircraft technicians undertake their workload without responding to it in a significantly negative manner, unless the designated work causes work-family conflict. A vision of career development is crucial to continuously elevate job passion in these individuals. Passionate aircraft technicians are motivated to contribute to aviation safety.

Reliability modeling based on Maximum Entropy and non-central moments as an alternative for RCM schemes or replaceable systems

This paper offers an alternative to determine reliability-centered maintenance (RCM) schemes for replaceable systems, when replacement times are censored and only the information that maintenance technicians, from the subjectivity of their experience, is available. Using differential entropy in information theory, and exploiting Lagrangian optimization algorithms, a Generalized Probability Density of Maximum Entropy (GPDME) is extracted. Lagrangian techniques provide a set of parameters that characterize the GPDME, the estimation of the parameters is done by first order perturbation of the integral of non-central moments, with which, the GPDME is typically built. In the emerging industry, RCM maintenance plans are not a common standard, in an attempt to put into practice, the benefits of RCM to this industrial segment, a case study, where the presented methodology was applied is provided. In the discussion and conclusions section, the areas of opportunity that are observed in the methodology presented in this work are adressed.

The Role of Maintenance in Reducing the Risk of Technological Disasters

In this article, we begin with characterization of technological disasters, emphasizing that human errors in one or more phases of the system life-cycle set the stage for disaster. To counter the unexpected, designers include multiple independent safety barriers capable of preventing the occurrence or mitigating the consequences of such unexpected events. The integrity of the barriers depends on adequate levels of maintenance. Maintenance actions sometimes cause technological disasters, but are shown in large part to prevent malfunctions in technology control systems and safety barriers. We argue that well-planned and executed maintenance actions are key in the reduction of risk of technological disasters. In our research, we reviewed well-documented technological disasters in a variety of organizations such as commercial aviation, nuclear power generation, and petroleum and chemical processing. Using a three-factor cause analysis scheme (human error, equipment or process failure, safety barrier failure) we analyzed twelve disasters and found these factors present in each disaster description. In each analysis, we paid particular attention to the role of maintenance managers and technicians in reducing the risk of disaster. However, maintenance was also a direct causal factor in six of the twelve (50%) disasters analyzed. In addition, we identified the phase of the technological system life-cycle when the disaster occurred.

A Web-Based Decision Support System for Aircraft Dispatch and Maintenance

Aircraft dispatch involves determining the optimal dispatch option when an aircraft experiences an unexpected failure. Currently, maintenance technicians at the apron have limited access to support information and finding the right information in extensive maintenance manuals is a time-consuming task, often leading to technically induced delays. This paper introduces a novel web-based prototype decision support system to aid technicians during aircraft dispatch decision-making and subsequent maintenance execution. A system architecture for real-time dispatch decision support is established and implemented. The developed system is evaluated through a case study in an operational environment by licensed maintenance technicians. The system fully automates information retrieval from multiple data sources, performs alternative identification and evaluation for a given fault message, and provides the technician with on-site access to relevant information, including the related maintenance tasks. The case study indicates a potential time saving of up to 98% per dispatch decision. Moreover, it enables digitalization of the—currently mostly paper-based—dispatch decision process, thereby reducing logistics and paper waste. The prototype is the first to provide operational decision support in the aircraft maintenance domain and addresses the lack of correlation between theory and practice often found in decision support systems research by providing a representative case study. The developed custom parser for SGML-based documents enables efficient identification and extraction of relevant information, vastly contributing to the overall reduction of the decision time.

Perencanaan Strategi Preventive Maintenance Pada Mesin Shot Blasting di PT. ABC dengan Klasifikasi ISMO

Mesin shot blasting merupakan mesin pembersih produk hasil pengecoran dengan mekanisme shoting bola baja dari gaya sentrifugal yang dihasilkan putaran impeller/blast wheel. Sebagai mesin utama dalam proses akhir kegiatan produksi pengecoran, penurunan kehandalan mesin sangat berdampak negatif pada sistem produksi. Saat ini strategi perawatan peralatan produksi di PT ABC masih menerapkan corrective maintenance yang pelaksanaan perawatnnya tidak terencana dan bersifat reaktif saat kegagalan fungsi mesin terjadi. Hal ini mengakibatkan tingginya production loss dan biaya perawatan meningkat. Oleh karena itu strategi perawatan pada mesin shot blasting diubah menjadi jenis perawatan pencegahan (preventive maintenance). Kajian ini bertujuan untuk merencanakan sistem preventive maintenance (PM) mesin-mesin shot blasting PT. ABC berupa pembuatan jadwal PM, perhitungan waktu downtime dan kebutuhan teknisi pada setiap kegiatan PM_nya. Perencanaan sistem PM dicapai menggunakan metode ISMO (Inspection, Small repair, Medium repair dan Overhaul) dan dilakukan dalam beberapa tahapan yaitu identifikasi obyek mesin, membuat spesifikasi kerja PM, menentukan nilai kerumitan dan siklus pemeliharaan, perhitungan tenaga kerja dan waktu downtime mesin, membuat jadwal tahunan dan bulanan, serta beberapa dokumen perawatan lainnya. Mekanisme penentuan nilai kerumitan, ditentukan berdasarkan kemiripan spesifikasi mesin yang terdapat pada metodologi HP Garg. Perencanaan sistem PM mesin shot blasting telah berhasil dilakukan, beberapa informasi PM yang diperoleh yaitu (i)siklus perawatan mesin adalah C - I1 - I2 - S1 - I3 - I4 - M1 - I5 - I6 - S2 - I7 - I8 - M2 - I9 - I10 - S3 - I11 - I12 – C, (ii) interval waktu antar kegiatan perawatan sebesar 1 bulan, (iii) waktu downtime kegiatan ISMO untuk mesin drum shot, batch shot dan hanger shot, (iv) jumlah dan level teknisi perawatan yang dibutuhkan pada setiap kegiatan ISMO untuk mesin drum shot, batch shot dan hanger shot. Verifikasi perhitungan nilai availability mesin shot blasting pada usulan jadwal PM diperoleh bahwa availability mesin meningkat menjadi lebih dari 80%.

Faktor-Faktor Pendorong Pengamalan Nilai-Nilai Islam dalam Kalangan Pelajar Malaysian Aviation Training Academy (MATA), Kuantan

This study aims to identify the motivating factors for the practicing of Islamic values among students at the Malaysian Aviation Training Academy. Crisis in moral and moral turmoil among students is the contributor of failure to translate Islamic values in the form of practicing in the daily lives of students should be carried out assessment so that the understanding and practization of Islamic values becomes the basis for students' lives. This study is in the form of surveys using adapted questionnaires certified by two assessors in the field of Islamic education who are experienced and have good reliability value. A total of 169 students from aircraft maintenance engineering licence courses (CAT B1.1) and aircraft maintenance technician licenses (CAT A1.1) through sampling techniques were easily involved in this study. The degree of reliability (alpha cronbach) for each study question is 0.85 for parental factor aspects, 0.79 for mass media factors, 0.74 for lecturer factors and 0.68 for peer factors. The data was analyzed using SPSS (Statistical Package for Social Science, Version 20. The findings found that lecturers were the highest factor with mean 4.33, followed by parental factors of 4.61, peer factor 3.65 and mass media 4.50. Finally, the implications of this study show that the emphasis on the practice of Islamic teaching is crucial so that students become a Muslim who practices good morals in everyday life based on the Quran and as-Sunnah to develop good student personality

Simultaneous scheduling of maintenance crew and maintenance tasks in bus operating companies: a case study

PurposeThe purpose of this paper is to describe an integer linear programming model to schedule the maintenance crew and the maintenance tasks in a bus operating company.Design/methodology/approachThe proposed methodology relies on an integer linear programming model that finds feasible maintenance schedules. It minimizes the costs associated with maintenance crew and the costs associated with unavailability. The model is applied in a real-world case study of a Portuguese bus operating company. A constructive heuristic approach is put forward, based on solving the maintenance scheduling problem for each bus separately.FindingsThe heuristic finds better solutions than the exact methods (based on branch-and-bound techniques) in a much lower computational time.Practical implicationsThe results suggest the relevance of such heuristic approaches for maintenance scheduling in practice.Originality/valueThis proposed model is an effective decision-making support method that provides feasible maintenance schedules for the maintenance technicians and for the maintenance tasks in a fleet of buses. It also complies with several operational, technical and labour constraints.

A dualistic model of air technician safety behavior: Application of the reformulation of attitude theory

Air technicians carry out critical responsibilities in aircraft maintenance. Their safety behavior is significantly and directly related to overall aviation safety performance. However, to date, only a limited number of studies have been devoted to discussion of air technician safety behavior issues. To gain an understanding of the related topics, in the current paper, Bagozzi's (1992) reformulation of attitude theory is applied to form a dualistic model identifying two types of stressors (i.e. challenge and hindrance) as the appraisal variables, and two types of job passion (i.e. obsessive and harmonious) as the emotional response variables. Air technician safety compliance and safety participation behavior are the targeted behavioral outcomes. A survey questionnaire is designed and distributed to collect data from Taiwanese maintenance technicians working for five national airlines. Structural equation modeling (SEM) is used to examine the hypothesized model. The results indicate that while the challenge stressor exerts more positive effects on harmonious job passion than on obsessive job passion, the hindrance stressor shows more negative effects on harmonious job passion than it does on obsessive job passion. Meanwhile, obsessive passion significantly and negatively affects air technician safety compliance and safety participation behavior. Harmonious passion, on the other hand, significantly enhances both types of safety behavior. The detailed discussion and implications of the findings are provided to serve as practical references for airlines when they are developing human resource management policies intended to enhance safety behavior on the part of maintenance crews. The research results will also be beneficial in terms of enriching the literature related to organizational safety behavior by offering the empirical evidence.

Virtual Simulation-Based Training for Aviation Maintenance Technicians: Recommendations of a Panel of Experts

<div class="section abstract"><div class="htmlview paragraph">A well implemented and suitable training plan makes a company's operations more effective. In the aviation industry, qualified maintenance technicians are one of the most significant assets to improve safety of passengers and reliability of air transportation. This paper investigated the effectiveness of virtual simulation-based training in the aviation maintenance. It garnered data from a panel of experts to discover if virtual simulation-based training can be used instead of the traditional training techniques to train maintenance technicians. From the aviation industry in Saudi Arabia, 11 experts were selected and interviewed. Experts were asked 9 questions seeking their opinions on utilizing the virtual reality technology on the aviation maintenance training, and if it can overcome the limitations of utilizing traditional methods while providing the needed skills. The panel of experts agreed that this technology is an efficient, practical, and doable method to be used in the aviation maintenance training. It provides a risk-free technique to train technicians. However, they stated that this technology should be used in combination with the traditional training methods to avoid potential problems and limitations, such as lack of equipment, time consuming, and exposing trainees to dangerous situations when using the traditional methods, and to avoid challenges, such as information technology (IT) infrastructure, high cost of implementation, lack of accountability, and more importantly, not offering a real sense of equipment when using the virtual reality technology. Therefore, the panel of experts recommended that this technology should be used as a Recurrent Technical Training (RTT) for maintenance technicians who already received an Initial Technical Training (ITT) using traditional techniques, hands-on training, for instance.</div></div>

واقع استخدام الوسائل التعليمية والتقنيات المتعددة في تدريس اللغة العربية في المرحلة الإعدادية من وجهة نظر مشرفي اللغة العربية ومدراء المدارس في بغداد

This study aimed to know the reality of using educational methods and various techniques in the preparatory stage to teach Arabic from the point of view of specialized supervisors and school principals in Baghdad ,and to identify the most important difficulties facing the use of educational methods and various techniques in teaching Arabic at the preparatory stage .In order to answer the study questions ,the researcher prepared a questionnaire that was applied to the study population ,which represents the supervisors specializing in the subject of Arabic language for the preparatory stage, and they number ten supervisors ,as well as the principals of preparatory schools in Baghdad (Rusafa|2) and their number is two hundred and forty administrators ,and by analyzing the statistical data, the results were reached ,The following: 1-The cassette recorder and audio tapes are the most available devices from the point of view of supervisors and school directors ,while transparencies are the least available educational devices in schools. 2-The most important obstacles facing Arabic language teachers in using educational tools and techniques from the point of view of supervisors and school directors is the lack of technicians for maintenance of educational devices and aids inside the school . 3-The degree of Arabic language teachers ,use of educational aids and various technologies is average . 4-Teachers are aware of all that is recent in field of educational aids and various technologies . 5-There are no statistically significant differences between the responses of supervisors and school principals on the whole study tool ln light of these results, the recommends ; 1-providing educational aids and technologies of all kinds in schools and giving teachers the opportunity to use them. 2-Holding training courses for teachers to train them in the use of various educational aids ,devices and technologies. 3-Attention by supervisors and managers to follow up teachers to urge and encourage them to use the various educational methods and techniques. Key words: educational aids, multiple technologies, middle school.

HFACS for Mapping Strengthening Human Factor Training Material on Prospective Aircraft Technicians

In order to reduce the number of flight accidents due to human factors, the ICAO issued Standards and Recommended Practices which were followed up by the Indonesian government by issuing regulations regarding the need to attend human factor training for technician personnel. One method that can be used to analyse flight accidents related to human factors is the Human Factors Analysis and Classification System (HFACS). HFACS analysis will be able to provide information about the weak points of the human factor, where this information will provide improvement in the material implementation of human factor training. This research is a descriptive study, where data obtained from online questionnaires will be analysed based on the HFACS. The population is aircraft maintenance technicians graduated from Surabaya aviation polytechnic for 410 people distributed in various MRO companies with samples taken for 186 people according to Herry King Nomogram, with a confidence level of 95%. The results of the analysis using the HFACS of the highest percentage are unsafe act operators, precondition for unsafe, unsafe supervision, organizational influence which is necessary to strengthen and enrich the syllabus of human factors on topic of human error, performance management, communication skill, situation awareness and reporting and investigating errors.

Work stress in aircraft maintenance technicians: The role of work-life balance

Work stress is a widespread issue among various kinds of employees because of its negative impact. This study aimed to determine the role of work-life balance toward work stress experienced by aircraft maintenance technicians. A total of ninety-two aircraft maintenance technicians participated in this quantitative approach using scales as the research instrument. The data were collected and then analyzed using multiple linear regression methods. The results showed that three dimensions of work-life balance, namely WIPL, PLIW, and WPLE, have a significant simultaneous role on work stress with an effective contribution of 56.5%. Partially, WIPL and PLIW significantly have a positive role on work stress with a contribution of 40.7% and 12.19%, whereas WPLE does not have a significant role on work stress. This study implies that a low level of WIPL and PLIW will reduce work stress levels in aircraft maintenance technicians and vice versa. Therefore, organizations can support aircraft maintenance technicians in managing work-life balance to maintain work stress levels.

Analysis for the Knowledge Management Application in Maintenance Engineering: Perception from Maintenance Technicians

Knowledge based on personal experience (tacit knowledge) acquired in problem solving actions and in maintenance actions is the fundamental basis for maintenance technicians in companies with great physical assets. Generally, there is no proper policy for managing strategic knowledge and its capture. In this article, through qualitative studies (grounded theory) and surveys conducted with technicians, the aim was to obtain the perception of the maintenance technicians’ part of the companies, in order to establish the characteristics of the relation between the strategic aspects and the engineering aspects of industrial maintenance, regarding knowledge management, as well as the enablers and barriers to its application. The results show how a high level of tacit knowledge is used in this activity, which requires more time for new staff. The values obtained from this survey show that the knowledge recorded by the companies (explicit) is 51.25%, compared to the personal knowledge (tacit) of maintenance technicians regarding reliability and breakdowns. In operational/exploitational actions it is 43.90%, for energy efficiency actions it is 49.61%, and in maintenance actions (preventive, predictive, and corrective) the value is 68.78%. This shows the significant gap between the perception of recorded knowledge (explicit), and the knowledge that maintenance technicians have (tacit knowledge). All this can affect the companies, as part of the strategic knowledge is lost when a maintenance technician leaves the company.

Qualitative Analysis of the Perception of Company Managers in Knowledge Management in the Maintenance Activity in the Era of Industry 4.0

In industrial maintenance activity, very sophisticated technical and human factors are needed to achieve the great process or service that the company provides, with a large dose of knowledge based on the personal experience of maintenance technicians. However, the management and application of knowledge in this activity is often relegated to a third level (or simply forgotten). The aim of this study is to identify, classify and prioritize the different barriers and facilitators that can be found in maintenance organizations of the company in reference to knowledge management in strategic maintenance activities, and what competitive advantages could be used for their appropriate introduction in the company. For this, qualitative techniques have been used through a field study and observation, as well as semi-structured interviews between company directors and maintenance managers of first-level companies in various sectors (industrial or services), to draw conclusions on the application of knowledge management techniques which help to determine the principles of a company that wants to face a knowledge management project within the area of maintenance engineering.

Human reliability increasing approach in aircraft maintenance technician’s training process

This article presents an approach for increasing the maintenance technician’s reliability by considering the human fault rate as utility function’s maximization problem in the technician’s training process. Adequately trained technicians are capable to perform a maintenance and manage the reliability of their assigned assets within the complex aircraft systems. In general, a degradation of aircraft reliability, due to maintenance tecnician’s competency, typically leads to significant, undesirable safety and economic consequences. In this article, an optimal control theory is applied on the purpose of finding of a fault rate reduction series in the training process which leads to highest technician’s reliability in the maintenance process of the complex aircraft systems.

Maintenance of Composite-Based Aircraft Components and Structures through the Perspective of Aviation Maintenance Technicians in the United States

For the last three decades, the field of aircraft construction and manufacturing has been experiencing a significant change as the material of choice for aircraft construction has been continuously transitioning from metal to composite materials. This underlying change to the way aircraft structures and components are manufactured is propelled by composite materials’ intrinsic design and operational advantages. Nevertheless, as new technologies are introduced into the aviation industry, it is crucial to consider how all aspects thereof are affected, most importantly to ensure that safety is not compromised. As a critical part of the aviation industry and a key factor influencing the safety thereof, maintenance activities and certified aviation maintenance technicians (AMTs) need to be considered when evaluating the impact of the introduction of composite materials in the aeronautical field. Consequently, the conducted study specifically focuses on aircraft maintenance activities, especially as it pertains to the interaction of certified AMTs with composite materials. The goal of the study was to highlight and understand the opinions and perceptions of AMTs on composite materials and how, from a front-line perspective, aviation maintenance activities have changed with the introduction of novel materials. The input gathered from AMTs is a tool to understand potential pitfalls, deficiencies in training and resources, and safety threats from a maintenance perspective that may stem from the increased use of composite materials. With this purpose, certified maintenance technicians in the United States were surveyed and their responses were analyzed to identify recurring themes in the topics presented. Responses indicated issues related to formal composite-centered AMT training, knowledge, and resources available for composite maintenance.

The Role of Smoke Detectors and Carbon Monoxide Detectors in the Fire Safety of Residential Buildings

Purpose: The aim of this publication is to present the most important aspects of using smoke and carbon monoxide detectors intended for households or similar residential facilities as well as to indicate the advantages and disadvantages of the adopted system solutions that affect the number of detectors installed in this kind of buildings. The article aims to present the issues related to the Integrated Qualifications System (ZSK), i.e. newly developed market qualification, dedicated to installers and maintenance technicians of smoke and carbon monoxide detectors. Introduction: Smoke and carbon monoxide detectors for early detection of existing threats such as fires or escaping carbon monoxide are an important element of fire protection, dedicated primarily to owners of residential buildings. In many countries in the EU it is obligatory to install detectors in homes, whereas at the moment in Poland the only aspect regulated legally is the obligation of the manufacturer of these products to obtain a certificate. Since 2016, the ZSK has been operating in Poland, in which in 2019 the qualifications of installers/maintenance technicians of smoke and carbon monoxide detectors were distinguished. As a result, a person with a market qualification certificate is prepared for independent installation and maintenance of fire safety monitoring devices Methodology: As part of the research process, theoretical research was used, such as: analysis of literature and legal documents, synthesis, general- ization, inference, comparison and analogy. As part of the research, documents from such countries as Poland, Great Britain (mainly England), Germany and France were analysed. The selection of individual countries was guided by the level of development of these systems in a given country and the availability of source documents Conclusions: The presented analysis of the requirements for the installation of the smoke and carbon monoxide detectors shows how different the ap- proach is regarding the use of this type of devices. Depending on experiences and the administrative structure of a given country, a variety of regulations, whether legal or normative, can be discerned in the use of smoke and carbon monoxide detectors. ZSK is a well-described system of formal organization and classification of competences and offers the public services at the highest possible quality level. It is also a partial solution to the problem of installing detectors. However, it is necessary to regulate this issue from the legal level, as it was the case in other EU countries, where the installation of detectors in homes is obligatory. Such action will contribute to reducing the victims of fires or inhalation of toxic gases (carbon monoxide) Keywords: Integrated Qualifications System (ZSK), smoke alarm detector, electrical apparatus for the detection of carbon monoxide, carbon monoxide, residential buildings Type of article: review article

Certificated AMTs: What Will Encourage More Women to Become Aviation Maintenance Technicians?

Certificated AMTs: What Will Encourage More Women to Become Aviation Maintenance Technicians?

Digital Assistance in the Maintenance of Offshore Wind Parks

Harsh environmental conditions, time pressure due to tightly calculated maintenance windows, complex technical systems and high quality standards determine the working environment for the maintenance and repair of offshore wind farms. Despite good qualifications and diverse training courses, maintenance technicians are reliant on information from manuals and checklists when performing their tasks and must document their work results in protocols. Both the supply of information and the data acquisition show a multitude of media disruptions. Hence, the processes on site and in the postprocessing are carried out slowly and uncertainly. The assistance system presented is intended to contribute to a consistently digital information flow and to support the technicians in a task-specific manner. Augmented Reality (AR) offers a way of presenting information and interacting with the assistance system during work execution. Using the example of the maintenance of crane systems used in a variety of ways in offshore wind farms, this article shows which potential can be tapped through digital assistance systems and AR applications.