Journal of Aviation Kapağı
Yayıncı
Vedat Veli ÇAY
e-ISSN
2587-1676
Başlangıç Yılı
2017
Dil
İngilizce
Durumu
Aktif
Dizin
Havacılık Dizini, TRDizin
Yayın Aralığı
Yılda 3 Sayı

Son Sayı (Latest Issue) - Year 2022 Volume 6 Issue 3

Abstract (Özet)

Unmanned aerial vehicles are aerial robots controlled by commands sent from the ground control station. While fixed-wing aircraft have the advantages of long range and high altitude, they need a runway to create sufficient lift on the wings. The advantage of Rotary Wing Aircraft is that it does not need a runway, it can perform vertical take-off and landing. It can hover. Thanks to these features, it is used in tasks such as surveillance, search and rescue, and reconnaissance. In areas with chemical wastes or in closed environments without risking the human element; Desired tasks can be performed in places such as sewers, caves, and collapsed houses. For this, there is a flight control computer and software on the aircraft. Rotary-wing aircraft are more unstable than fixed-wing aircraft. Thanks to the flight controller, its stability and controllability are increased. In this study, a quadcopter, multicopter aircraft structure is used. The variation of the angle between the arms of a quadcopter aircraft and its effects on forward and sideways flight are examined. It is required that the aircraft be symmetrical in the longitudinal and lateral axis in order to cope with the disturbances to which it is exposed in external environments. In closed environments, atmospheric events are replaced by obstacles. One of the desirable features of the aircraft is that it can pass through narrow places. For this, the aircraft must perform a shape change. The change in structure will cause it to change in the dynamic’s equations, causing the rotors to react differently during linear and rotational movements of the aircraft. This study focuses on the system design and control of the aircraft. The geometric features obtained from the aircraft designed in the CATIA program were used in the creation of the mathematical model. The obtained values were created using the MATLAB Simulink program to create a digital twin of the aircraft. When the intersection angle between the arms is 90 degrees, the settling time of the 2-degree pitch angle is 7.48 seconds, and when it is 45 degrees, it is 10.3 seconds.

Abstract (Özet)

Due to the brittle nature of the optical parts used in the grinding process to obtain a good surface quality, surface roughness and subsurface damage occur after the machining. These subsurface damages must be detected and destroyed with the help of post-process processes such as polishing. Because detecting these damages is time-consuming and costly, many researchers have tried relationship between subsurface damage and surface roughness since it is easier to detect and measure. In this study, Zerodur glass ceramic material characterization tests were carried out to predict the surface roughness and damage under the surface, and the material properties were determined to be specific to the sample. The grinding parameters taken from the previous studies and the values given for surface roughness and subsurface damage were examined with the help of the Lambropoulos theoretical model. The results theoretically showed that with the characterization of material properties different from those given in the literature, even if the parameters used in the experimental study do not change, much more severe subsurface damage will be created on the sample, and the load value applied to the material will increase significantly. For this reason, it is crucial to determine the material's mechanical properties by performing characterization tests before all material grinding and post-processing processes.

Abstract (Özet)

The focus of this study is the experimental investigation of the effects of canola methyl ester (CME) and Jet-A1 fuel blends on performance and emissions of the mini-scale turbojet engine at different blend ratios and real flight power levels. Accordingly, B2.5 (2.5% CME-97.5% Jet-A1), B5 (5% CME-95% Jet-A1) and B10 (10% CME-90% Jet-A1) fuel blends and pure Jet-A1 fuel and power rates of taxi (7%), approach (30%), climb (85%) and take-off (100%) were tested and examined for static thrust, TSFC, EGT, emissions, noise and thermal efficiency. The results obtained show that up to 5% CME addition in turbojet engine has a maximum reduction effect of 19.6% on thrust, while this ratio is much less in partial power situations. This effect also causes an increase in the TSFC value. While the CO2 value increased with the addition of CME, it caused a decrease in the CO and unburned HC values. However, the addition of CME caused increasing on noise level especially in taxi power state (about 7.8%), while no significant noise increase was observed in other power states. In terms of thermal efficiency, it has been observed that all fuel blends reduce efficiency in different power states, and it can be said that especially B5 fuel blend can be used as a blend fuel in gas turbine engines at partial loads.

Abstract (Özet)

This research examined the evolution of low-cost carriers (LCCs) in the Trans-Tasman aviation market, quantifying their impact and qualifying their influence on the market. New Zealand is Australia’s second largest tourist market, and the air routes to Australia are New Zealand’s busiest; as such, the trans-Tasman passenger traffic is of significant economic and strategic interest. This study utilized an exploratory research design and an in-depth longitudinal research approach to examine the evolution of the market and to understand the process of market development. The qualitative data was examined by document analysis. The study period was from 1995 to 2020. The low-cost carriers (LCCs) first entered the market in 1995. The case study revealed that since that time, the market has broadly had four discrete phases. The first phase was from 1995 to 2003 when the first low-cost carriers (LCCs) entered the market; the second phase saw the rapid growth in traffic following the launch of services by Pacific Blue Airlines (a subsidiary of Virgin Blue) and Jetstar Airways. An important development in the market took place in 2010, when Pacific Blue was rebranded Virgin Australia, and, as such, implemented the full-service network carrier (FSNC) business model. In 2016, AirAsia-X entered the market, utilizing fifth freedom traffic rights, to provide daily Airbus A330 services from Coolangatta to Auckland. AirAsia-X exited the market in early 2019 leaving Jetstar Airways as the sole low-cost carrier operating in the market (Phase 4).

Abstract (Özet)

This study aims to analyse the sense of humour of drone pilots depending on the amount of time they have used the drones, the sort of instruction they have gotten, and their educational levels. The study covers 148 male drone pilots with drone education backgrounds. The Humour Styles Questionnaire is used to collect data for this study. The specified statistics, reliability analysis and MANOVA analyses were employed to analyse the collected data.As a consequence of these analyses, there was no significant statistical difference between the humour questionnaire sub-dimensions of participative humour, self-developing humour, aggressive humour, and self-destructing humour. Participatory humour, self-enhancing humour, offensive humour, and self-defeating humour sub-dimensions were not significantly different by income level. There was no statistically significant difference in the sub-dimensions of the humour scale according to education level: participative humour, self-enhancing humour, offensive humour and self-defeating humour. As a result, the sense of humour of drone pilots does not differ based on the type of schooling, income level, or education level within the contents of this study.

Abstract (Özet)

This study gathered statistical data about bird strikes from various countries, including Türkiye. The study aims to compare the bird strike events that occurred in Türkiye and other countries by investigating bird strike data analysis from targeted countries. In this context, data on bird strikes per 10000 flights, distribution of the number of birds strikes according to months, phases of flight, the components hit by the birds, and the time of the event occurred on a day were presented. The data includes findings from Türkiye, USA, UK, Australia, Finland, Iran, and Czechia. When the results were evaluated, it was concluded that bird strikes are an essential factor to consider for safety and risk management. It is crucial that countries must conduct regular reporting to manage this safety issue. With the help of appropriate modelling conducted via proper measurements, the industry will come a long way in solving the safety issues caused by bird strikes.

Abstract (Özet)

Aviation management is a broad field of science that encompasses all kinds of managerial and operational processes, generally in the safe transportation of passengers and cargo within the aviation industry. However, this branch of science, which is still very young in the history of science, acts as a catalyst in the economy by adding high added value to the world trade volume. This industry, which gained momentum with the liberalization period after 1980, has an ecosystem in which strong organizational structures can hold. With its key functions such as safety management, human resources management, marketing management, and financial management in terms of its scope, it needs a visionary perspective with a working area within the airport management network. From this point of view, understanding the development processes of the field in the literature and revealing its relationship with other variables will provide a systematic and holistic perspective to the related literature. For this purpose, the bibliometric analysis method was used in this study, which was conducted in the field of aviation management. The study covers a process, especially from the liberalization period to the present. The purpose of this study in the field of aviation management is to create a perspective on the aspects in which the field offers mobility, the development, quality, and quantity of the process. In this context; In this content; Studies in the field of aviation management were taken from WEB of Science (VOSviewer). Word cloud and keyword maps were created covering the distribution of the studies by years, the authors who contributed the most to the field, the institutions, and journals according to the number of publications, and the languages used in the publications. The contribution levels of the studies to the literature and the areas in which the subject interacts are explained.

Abstract (Özet)

With increased performance expectations based on speed and agility in logistics flow and supply chain processes, air logistics has gained popularity as a research area. Although more and more papers are published each year on this subject, to the best of our knowledge, a comprehensive bibliometric academic publication review has not been presented so far to contribute to the intellectual structure of the literature. Therefore, this study aims to investigate the last 5 decades’ intellectual basis of air logistics studies that can be evaluated in the field of social sciences. For this purpose, a total of 398 articles have been accessed to be used in the bibliometric analysis of studies published in the literature of air logistics, and these data have been provided from the Core Collection Database of Web of Science (WOS). The research data consists of articles published in English in the WOS database between 1971 and 2019. Books and papers published in all other languages were not included in the research. The Bibliometrix (Biblioshiny) package of the statistical software program R was used for the analysis and visualization of the data. Research findings indicate that air logistics research has increased greatly, especially in the last 10 years. The most productive countries are the United States, China, and Canada, respectively, while the most published journal is the Journal of Air Transport Management, which has continued to increase its number of publications since 1995. Although there are no tear restrictions in this study, the number of publications on air logistics in the field of social sciences is still insufficient.

Abstract (Özet)

The deregulation of air transport created the need to safeguard an acceptable level of air connectivity between urban centres and remote European regions. To this end, several protection schemes have been developed around the world, including the imposition of Public Service Obligations (PSOs) in a few European air routes. Thirty years after the establishment of PSOs in Europe, the debate over their efficiency and effectiveness is still active. This paper offers an overview of the European PSO program along with a review of the academic literature exploring the main issues that accompany the PSO scheme. The main findings that call for consideration from both scholars and policymakers are the need to strengthen the competition in these non-commercially attracting routes, the necessity for central network design and coordination and the requirement for transparency and open dissemination of information regarding the PSO routes.

Abstract (Özet)

Air transportation is the significant mode of transmission, enabling the worldwide spread of infectious diseases through the mobility of infected persons. Therefore, governments applied the most comprehensive restrictions and preventions in civil aviation during COVID-19. The industry is one of the most economically impacted due to travel, and flight restrictions. This paper aims to investigate the long- and short-term nexuses between government responses to COVID-19 and the aviation stock prices traded in Borsa Istanbul. The OxCGRT stringency Turkey index is used to measure the Turkish government responses and policies to COVID-19. In the study, the daily data of Turkish Airlines, Pegasus Airlines, Do&Co Catering, TAV Airport Holding, Celebi Ground Handling stock prices, and the OxCGRT stringency Turkey index for the 24.01.2020-11.11.2021 period were used, and Granger causality and Engle-Granger cointegration tests were applied to reveal the nexuses. In conclusion, there is a cointegration nexus and one-way causality from the index to all Turkish aviation stock prices, except the Celebi Ground Handling stock prices. The contribution of this study is that it is probably the first one in Turkey to reveal the nexus between the government's policy and responses to COVID-19 and aviation stock prices.

Abstract (Özet)

A high level of cancer awareness may contribute to early diagnosis and improve cancer survival. This study is aimed to assess the level of awareness of occupational cancer among airline pilots. To the best of the authors’ knowledge, this study has examined pilots’ occupational cancer awareness levels for the first time. A brand-new cancer awareness survey was used to examine the awareness level of airline pilots on cancer. The analysis of variance (ANOVA) method was employed to analyze the survey results. The response rate was % 43.6. Data had been collected from 523 individuals, 48 of whom were female pilots. Of the participants 67.3% were long-haul pilots. Female airline pilots were much more aware of cancer in comparison to male airline pilots. Pilots flying 81-90 hours per month were much more aware of cancer in comparison to other participants. Academic articles, magazines and social media were sources of knowledge for 64.6 % of pilots whereas 39.5% of pilots were informed by e-learnings and recurrent trainings regarding the occupational cancer. According to the findings of this study, there is a need for training and media-based interventions to raise awareness and instil safe and healthy lifestyle practices at the workplace in the airline industry.

Abstract (Özet)

In the aviation sector as unscheduled maintenance, repair and overhaul cost too much and these activities also negatively affect the prestige of the companies, deciding the most appropriate maintenance strategy is crucial. Today artificial intelligence methods, especially machine learning techniques facilitate failure detection and predict the wear and tear of the equipment before the occurrence of a serious failure. In this paper, artificial intelligence-supported corrective, predictive, and prescriptive maintenance methods are examined. Those most common aircraft maintenance approaches are compared regarding cost, reliability, failure detection, and downtime period using decision makers' subjective evaluations with the help of the q-rung orthopair fuzzy TOPSIS method which mitigates the drawbacks of uncertainty in human decision making. Stable and efficient results are obtained regarding the selection of an appropriate maintenance strategy. This article might be the first quantitative research that evaluates and compares AI-supported aircraft maintenance strategies.

Abstract (Özet)

Aviation; it is a global sector that affects many areas such as education, trade, tourism, and is also affected by many situations such as epidemics, economic fluctuations, political disagreements and military intervention. For this reason, the disagreement between Ukraine and Russia also quietly affects the aviation industry. Although disagreements seem to continue between the two countries, issues such as the closure of airspaces, changes in flight costs as a result of changing routes, the situation of aircraft and component manufacturers, tourism and aviation security concern aviation globally. In this study, which was conducted to reveal the impact of the Ukraine-Russia conflict on the aviation sector, case study research, one of the qualitative research methods, was used. In a four-month period, sources such as newspaper news, internet news sites, websites of authorities were scanned, and it was tried to reveal how the conflict was reflected in the aviation industry. This method was chosen considering that it is suitable for this study in terms of revealing what happened in the past, how people were affected, how the processes took place, and what the results were. Between February 24 and March 2, when the disagreements between the two countries began, all flights to Ukraine were stopped, while air traffic in neighbouring countries decreased. International passenger traffic of Russian airlines decreased by at least four times in March 2022 compared to March 2021, and by sixteen times compared to March 2019. The Ukraine-Russia conflict also negatively affected the flight times of passenger flights between East and West. As a result of the study, the great impact of the four-month period, which is thought to be short, on the aviation sector has been tried to be revealed.

Abstract (Özet)

Deregulation and liberalization acts have contributed to the emergence of various airline business models (ABMs) in the airline industry by putting competition ahead. Influenced by catastrophic crises, increased competition, and changes in customer needs and expectations, airlines have had to innovate their business models or converge them with others over time. Thus, the topic of ABM has attracted tremendous scholarly attention. However, the extant literature lacks a visualized bibliometric study that investigates the evolution of ABM in depth. In this context, this paper employs a comprehensive visualized bibliometric analysis through CiteSpace software to present the evolution of the topic “airline business model” and its possible trends in the post Covid-19 era by benefiting 652 articles on ABMs published during the period from 1985 to 2021. The results reveal that studies on ABMs have increased especially over the past few years, and Journal of Air Transport Management is the leader outlet preferred by authors on this topic. In addition, although studies on low-cost carriers have an obvious dominance over studies on other ABMs, the results provide some evidence that studies on long-haul business models will increasingly continue in the future.

Abstract (Özet)

The aim of this study is to investigate the organizational commitments of flight attendants of different generations who work in airline companies operating in Turkey. The analysis stage of the study, a questionnaire was offered to 351 people, who work as flight attendants in the public and private airline companies operating in Turkey, and a study to identify the levels of organizational commitment in terms of generational differences was conducted.The method of data collection using questionnaire, which was considered the most suitable method for the context of the study based on the literature search, was used. The questionnaire includes, in addition to the demographic information, questions which would support the main and sub-hypotheses and Organizational Commitment Questionnaire by Allen and Meyer (1984) to measure organizational commitment level. With the study, generational differences of the flight attendants who work in airline companies were studied within the scope of affective commitment, continuance commitment and normative commitment dimensions, which are the sub-dimensions of organizational commitment. Data were analysed using SPSS 21.0 software. The concept of organizational commitment is analysed based on these variables: sub-dimensions of organizational commitment, generational differences, gender, marital status, educational status and the duration of working in the industry. In the analyses, in addition to the descriptive statistics, t-test and unidirectional analysis of variance methods were used. At the end of the study, differences were observed among the organizational commitment sub-dimensions of the flight attendants working in airline companies in terms of generational differences.

Abstract (Özet)

In recent years, psychological empowerment has been a tool to solve management problems arising from the need for creativity, innovation, and flexibility. In an environment where competition is intense, meeting the needs and expectations of conscious customers is only possible with a working style that can benefit from the initiative of the personnel. The concept of self-leadership consists of the theory of self-control and includes the concepts of self-influence and self-leadership. This study examines the mediating role of proactive personality in the effect of psychological empowerment on self-leadership. In this direction, a questionnaire was applied to 406 people in the province of Istanbul, including the cabin cockpit, ground services, operations, and general directorate in the civil aviation industry. The study used a structural equation model for the analysis. As a result, it concludes that personality has a partial mediating role in the effect of psychological empowerment on self-leadership. It suggests a need for personnel who can take the initiative, manage themselves, and adapt quickly to change, especially in the aviation sector, where safety and security are the most critical factors. Accordingly, there is a need for appropriate industry professionals in recruitment, selection and placement, training and development, and talent and career management. This need will continue to grow in the future.

Abstract (Özet)

Air freight transportation has major advantages such as rapid and safe transit of goods compared to other transportation modes. As well as other transportation sectors growth rate of air freight transportation is related to global supply chain. Air freight sector fundamentally includes freight forwarders, integrators, warehousing, customs, agents, airport terminal operators, and air freight carriers. Cost of air freight transportation is dependent to carrier expenses including costs of ground and flight crew, fuel, aircraft maintenance and insurance. But environmental prevention costs are usually missed out and disregarded. But environmental costs gained importance for many enterprises as well as airway companies after Kyoto and Paris Agreements. The current paper describes an approach to calculate prevention cost of air freight operations induced air pollutants. For this purpose, air freight traffic in an International Airport located in Isparta, Turkey is considered to present the approach. At the end of the study environmental cost of each air pollutant emissions, annual environmental cost of flight operations in the airport, and annual environmental cost per unit freight are calculated and compared in terms of yearly variation. The presented approach is employed to evaluate environmental costs related to air freight traffic in an International Airport for the first time.