As variáveis que exercem influência em um setor podem torná-lo complexo e imprevisível. A complexidade de um setor, quando existente, é uma característica intrínseca e não pode ser evitada, sendo necessário que a empresa primeiramente compreenda e se adapte a essa complexidade a fim de obter vantagem competitiva frente a seus competidores. A imprevisibilidade também não pode ser evitada, entretanto pode ser também compreendida e atenuada. O setor de aviação é influenciado por diversas variáveis, sejam elas internas ou externas, o que o torna complexo e imprevisível. Principal exemplo de influência interna, a estratégia deve servir como um direcionador a todos dentro de uma organização, para que os objetivos delineados pelos executivos sejam alcançados. A definição da estratégia deve ser seguida de uma exaustiva análise da influência dos agentes externos ao setor, com o objetivo de compreendê-los e assim fazer com que os seus efeitos, quando negativos para a empresa, sejam os menores possíveis. Invariavelmente afetados pelas influências internas ou externas, sejam elas quais forem, estão os custos das companhias, que ao longo dos últimos 90 anos, passaram de um ordinário indicador de controle a uma ferramenta de auxílio às decisões estratégias, por meio da gestão estratégica de custos. No setor aéreo brasileiro, mais especificamente na aviação comercial, os custos passaram a ter maior importância a partir dos primeiros movimentos de desregulamentação do setor, iniciado em novembro de 1991, até a entrada no setor da companhia GOL, que trouxe um novo conceito para o país de gestão de custos, graças à retirada das últimas regulamentações ao controle das tarifas. Esse novo foco em custos iniciou uma nova etapa na competição das companhias aéreas no Brasil e introduziu a experiência de voar a novos passageiros, antes restritos ao transporte rodoviário por causa dos altos custos das passagens aéreas nos anos anteriores. A busca por custos mais baixos é comprovada com os resultados das análises, assim como a existência da diferenciação, principalmente no segmento internacional. O período de 2000 a 2010 foi marcado por diversos acontecimentos no mundo, como guerras, atentados terroristas, crises econômicas mundiais, todos esses com influência nos custos das companhias aéreas brasileiras. As análises de custo unitário demonstram a influência desses fatores, principalmente no custo de combustível, principal componente dos custos das companhias. / The variables that influence a sector can make it complex and unpredictable. The complexity of a sector, where it exists, is an intrinsic feature and cannot be avoided, being necessary for the company to first understand it and adapt it in order to gain competitive advantage against its competitors. The unpredictability cannot be avoided; however it can also be understood and mitigated. The aviation industry is influenced by several variables, whether internal or external, which makes it complex and unpredictable. Prime example of internal influence, the strategy should serve as a guide to all within an organization, so that the goals outlined by the executives are achieved. The definition of the strategy should be followed by an exhaustive analysis of the influence of external agents to the sector, in order to understand them and thus make their effects, while negative for the company, are as small as possible. Invariably affected by internal or external influences, whatever they are, are the costs of companies, which over the past 90 years, went from an ordinary control indicator to a tool to help decision strategies to be made, through strategic cost management. In the Brazilian airline industry, specifically in commercial aviation, the costs have been given greater importance from the first movement of deregulation, initiated in November 1991 until the entry into the industry the company GOL, which brought a new concept for country of management costs, mostly because of the withdrawal of the last regulations to control rates. This new focus on costs started a new stage in the competition of the airlines in Brazil and introduced the experience of flying to new passengers, previously restricted to road transport, because of the high cost of airline tickets in previous years. The constant search for lower costs is evidenced by the analyzes, as well as the existence of differentiation, more specifically in the international segment. The period from 2000 to 2010 was marked by several events in the world such as wars, terrorist attacks, global economic crisis, all of those with influence in the cost of Brazilian airlines. The unit cost analyzes demonstrate the influence of these factors, specially the cost of fuel, the main component of airlines costs.

This thesis explores methodologies of modeling and evaluating the operational performance of a typical aeroengine having field experience over two decades. Upon failure, the engine is repaired and restored to flight worthy condition and hence comes under the purview of repairable systems. Operational performance of the engine is being measured in terms of five functions of time, namely, M(t), which is the expected number of system failures in the time interval [0,t]; system failure rate m(t), which is an unconditional quantity and is simply the derivative of M(t); ρ(t), the conditional failure intensity given the history of a system Ht, which is nothing but limdt→1 Prob(System fails in [t,t + dt] |Ht); and M′(t) and m′(t), which are 0 dt conditional entities analogous to M(t) and m(t) defined in the same spirit as that of ρ(t), the details of which are given in the third chapter of the thesis. These functions are being estimated using field failure-repair data of 418 aeroengines, where the observations on time between failures are being measured in number of flying hours logged in between failures, and the corresponding repair duration is being measured in number of calendar days. To start with, using the superimposed renewal process model the above quantities M(t), m(t), m′(t), M′(t) and ρ(t) are estimated both in the frequentist as well as the Bayesian framework. Subsequently repair times have been incorporated into the model and analysed using both frequentist and Bayesian approaches. Next, the model of Lawless and Thiagarajah (1996) which incorporates both renewal and time trend, has been generalized to include repair time as well, and a comprehensive methodology of Bayesian model selection under this model has been developed. After introducing the research problem in the first chapter, the engineering system description leading to the identification of the failure modes, repair practice and the variables of interest is taken up in the following chapter at the outset, as a pre-requisite to the stochastic modeling and the statistical analysis that to follow in the remainder of the thesis. As the first stochastic model, the number of system failures in a given time interval is modeled as a superimposed renewal process with the constituent independent renewal processes running in different component sockets having Weibull inter failure times. This model is first empirically validated using the field failure data and then using this model, the five quantities of interest as mentioned above viz. M(t), m(t), ρ(t), M′(t) and m′(t) are analysed from a frequentist maximum likelihood perspective. A Bayesian analysis of the same follows in the subsequent chapter. Next, the repair effect is incorporated into the superimposed renewal process model by considering the Weibull parameters of inter failure times of the constituent renewal processes running in independent component sockets as a polynomial in the last repair time. The nature of this polynomial relationships are empirically deter-mined and the Weibull assumption is validated through a test of hypothesis. Different polynomial relationships lead to consideration of several models, with the correct ones chosen through a series of likelihood ratio tests. Next based on the appropriate models a maximum likelihood analysis of M(t), ρ(t) and M′(t) has been carried out. Like the simple superimposed renewal process model, Bayesian analysis of this model incorporating repair times is carried out in the following chapter. In the Bayesian setup however, the problem of model selection could be kept unrestricted to non-nested models as well (unlike the previous chapter, where only nested models could be considered), and a comprehensive model selection exercise has been carried out with the aid of intrinsic Bayes factors and training data sets. The last but one chapter presents a generalised model of Lawless and Thiagarajah (1996) for performance evaluation of aeroengines that incorporate renewals, time trends and the repair characteristics. Here also since the primary problem is one of model selection, the entire analysis like in the preceding chapter has been carried out under the Bayesian frame-work. The final chapter concludes the thesis by comparing the empirical results obtained in the previous five chapters, summarising the main contributions of the thesis and providing directions for future research.

Dans le milieu aéronautique professionnel (un des secteurs professionnels les plus sûr au monde), la gestion des conséquences des erreurs humaines doit être améliorée pour garantir une sécurité maximum. Pour ce faire, il est nécessaire de mettre en place des techniques de conception centrées sur l’utilisateur. Cependant, la mise en place de ces techniques est rendue difficile par les particularités des systèmes sociotechniques complexes (la certification, la complexité des systèmes conçus, le nombre de personnes impliquées…). Notre étude a pour but de développer et de valider des outils d’aide à la conception centrée sur l’utilisateur, notamment pour le traitement automatique de grande quantité de données. Pour ce faire, nous avons, dans un premier temps, réalisé une étude basée sur le jugement d’expert visant à identifier, dans une base de données, des scenarii susceptibles de contenir une erreur de l’équipage. Les résultats de cette méthode par jugement d’expert ont été comparés à ceux obtenus à l’aide d’outils de traitement automatique. Cette comparaison a permis :1/ D’identifier des algorithmes pertinents pour l’extraction d’information dans des bases de données (algorithme des plus proches voisins et de filtrage bayesien) ;2/ De proposer une méthodologie permettant l’extraction automatique de situations à risque pouvant donner lieu à des études plus approfondies, sur simulateur par exemple. Cette étape est primordiale dans cadre de la conception centrée utilisateur.Les liens établis avec les études des incidents/accidents laissent envisager des impacts positifs sur la sécurité aérienne. / In the professional aeronautical field (one of the safest in the world), human error management must be improved to reach a better safety level. To do this, a user centred design process has to be implemented. However, due to the complexity of socio technical systems, the implementation of an efficient user centred design process could be challenging. To ease this process, our study aims to develop and validate specific tools, particularly for processing large amounts of textual data. In our study, we will firstly undertake an extraction of scenarios that can contain human errors in a specific database. This extraction will be based on expert judgment (control condition). Secondly, we will confront the control condition with results obtained automatically. The results of this comparison allow:1/ The identification of relevant algorithms for automatic information extraction within large textual databases (Nearest Neighbour, Bayesian filtering);2/ The identification of a methodology to extract risk situations that could be included in specific studies. This step is very important for the user centred design process.Links that we have established between our results and incident/accident studies allow us to consider positive impacts on aviation safety.

Comprising many airplanes, airports, aircrew, and employees, aviation industry is a large sector that is very vulnerable to attacks, whether it is from terrorists or criminals. Aviation history is fraught with examples of airport bombings, hijackings, and sabotage terrorist attacks. The most destructive of which is the tragedy of September 11, 2001, the cornerstone of today's aviation security policies. This study uses risk assessment tools to determine the dimensions of danger and threats against the aviation industry and addresses how vulnerable the aviation sector is. After vulnerabilities and threats are examined, possible impacts of attacks against the aviation security are discussed. This study also explores the pre and post September 11 policies that governments and policy makers develop to reduce risks in aviation sector. In addition, it discusses weaknesses and strengths of these policies which surfaced during the implementations. Finally, this study proposes some recommendations based on vulnerabilities and threats of aviation security.

This Master´s thesis examines Investigation of aircraft accidents / incidents, which were caused by human error. My thesis is focused on fixed wing aircrafts with maximum take off weight up to 2500 kg. Practices of Aircraft accident / incident Investigation are described in Annex L13 which is document published by Ministry of Transport of the Czech Republic. This document provides some support for investigators but does not contain methodology which should be used to discover human error by which the accident / incident was caused. This thesis has two major purposes. First purpose is to analyze Final reports of investigations and suggest improvements which can be made. Second goal of this thesis is to create own methodology for investigating the causes of aviation accidents / incidents caused by human factor.

Sweden has an ambitious goal that the country will be carbon neutral by 2045, where this includes all sectors, including transportation and thus aviation. The aviation sector is an important part of the transportationsystem where the development of society has become dependent on this transportationalternative. In 2017, the aviation accounted for six percentof Sweden’s carbon dioxide emissions, one percentfrom domestic flightsand five percentfrom international flights. In order toreduce these emissions, active work is ongoing for a transition where domestic aviation will be fossil-free in 2030 and all departures from Sweden to the international market will be fossil-free in 2045. Aviation has historically had a strong connection to fossil fuels and environmentally friendly alternatives have not yet managed to compete in the market.This study has investigated how sustainability can be a central part of the business model and how these should be adapted as part of the work to a fossil-free business, as well as the role of sustainable aviation fuels (SAF) and policy instruments in the energy transition. By mapping important aspects for sustainable business models, market potential for SAFand the development of new policy instruments,this study contributes with a systems perspective on the Swedish aviation industry's energy transition. The delimitationofthe study has been the Swedish market with focus on actors with their operations in Sweden. The methodologyhas consisted of a literature study, an interview study with 11 actors in the Swedish market and a case study on the airline corporationBraathens Regional Airlines (BRA), which mainly operates domestic flights in Sweden with Bromma as their headquarters.The results showed that there are three areas that are important in the work with sustainable business models, three areas for the market potential for biofuels and four areas for policy instruments. In the development of sustainable business models, cooperation and co-financing are seen as central aspects for an effective transition with better risk distribution. Transparent sustainability work, climate calculations and biofueltickets are considered important tools to increase the customer's understanding of the company's transition towards a sustainable future. The public's lack of knowledge regarding the energy transition for aviation is considered an obstacle towards increased sales of biofuel tickets, which also creates flygskam and avoidance of aviation as a means of transportation. The biggest obstacle towards an increased share ofSAFon the Swedish marketis mainly considered to be the lack of Swedish production.Increased production would mean large investment costs and high risks, which means that co-financed projects are proposed to overcome this obstacle. Biomass as a raw material and how it is used and classified in the EU is also an obstacle towards increased use. Current policy instruments show that the reduction obligation is a positive addition, but the penalty fee needs to be raised above the price of SAF.The EU taxonomy can also play a decisiverole in the transitionprocess, as the classification of biomass and bioenergy can affect interest and willingness to make new investments.In addition, travel policies of companies are an obstacle when they prohibit travel by aviation.Finally, policy instruments are needed that favor Swedish production of SAF, where the industry sees great opportunities in both technology and raw materials, but lack of political initiatives.

Doctor of Philosophy / Department of Psychology / Richard J. Harris / Systems that support or require human interaction are generally easier to learn, use, and remember when their organization is consistent with the user’s knowledge and experiences (Norman, 1983; Roske-Hofstrand & Paap, 1986). Thus, in order for interface designers to truly design for the user, they must first have a way of deriving a representation of what the user knows about the domain of interest. The current study evaluated three techniques for eliciting knowledge structures for how General Aviation pilots think about weather information. Weather was chosen because of its varying implications for pilots of different levels of experience. Two elicitation techniques (Relationship Judgment and Card Sort) asked pilots to explicitly consider the relationship between 15 weather-related information concepts. The third technique, Prime Recognition Task, used response times and priming to implicitly reflect the strength of relationship between concepts in semantic memory. Techniques were evaluated in terms of pilot performance, conceptual structure validity, and required resources for employment. Validity was assessed in terms of the extent to which each technique identified differences in organization of weather information among pilots of different experience levels. Multidimensional scaling was used to transform proximity data collected by each technique into conceptual structures representing the relationship between concepts. Results indicated that Card Sort was the technique that most consistently tapped into knowledge structure affected by experience. Only conceptual structures based on Card Sort data were able to be used to both discriminate between pilots of different experience levels and accurately classify experienced pilots as “experienced”. Additionally, Card Sort was the most efficient and effective technique to employ in terms of preparation time, time on task, flexibility, and face validity. The Card Sort provided opportunities for deliberation, revision, and visual feedback that allowed the pilots to engage in a deeper level of processing at which experience may play a stronger role. Relationship Judgment and Prime Recognition Task characteristics (e.g., time pressure, independent judgments) may have motivated pilots to rely on a more shallow or text-based level of processing (i.e., general semantic meaning) that is less affected by experience. Implications for menu structure design and assessment are discussed.

Competitiveness and gaining a sustainable competitive advantage are very important factors when analysing the success of companies involved in the aviation industry in South Africa. The success of these companies will depend on their ability to maintain technological capabilities in the areas of human resources and product development. Global aviation currently is concentrated in a few countries, with the USA being the largest contributor to an industry which is regarded as one of the fastest globalizing industries in terms of market structure and production systems. In South Africa, companies have managed to develop skills in aviation manufacturing. The opportunities that will be created, owing to changes in global production chains, will enable South African companies to establish themselves further as global suppliers. The aviation industry contains high risks, especially because it is considered to be the industry which acts as a driver for innovation. Complexity of production, the capital-intensive nature and high risks involved in developing new products and services have linked the industry to inevitable political influence and support. The industry can broadly be divided into two main sectors: military and commercial. Analysts predict that opportunities in the global aviation markets in future will increase considerably. This is attributed to more Asian, African and Latin-American regions capitalizing on opportunities that exist mainly within the commercial sector. They will form strategic alliances which will enable them to perform on low-cost platforms and offer exceptional services to major players in the aviation sector. To capitalize on these opportunities, companies need to analyse their external and internal environment. The main objective of this study is to analyse and to evaluate the competitive environment of a selected aviation company, to ensure that the best strategy is chosen and adopted and to confirm that the company can create and sustain a competitive advantage over competitors. The planning tools utilized in this study are the PEST and SWOT analyses. Both have been used in the strategic planning process of many other firms. These analyses have proved to be the key element needed to formulate an action plan to be and to stay competitive in the aviation industry. This study evaluates both of these planning tools and applies them to the company chosen for this case study. / MCom (Management Accountancy), North-West University, Potchefstroom Campus, 2014

Competitiveness and gaining a sustainable competitive advantage are very important factors when analysing the success of companies involved in the aviation industry in South Africa. The success of these companies will depend on their ability to maintain technological capabilities in the areas of human resources and product development. Global aviation currently is concentrated in a few countries, with the USA being the largest contributor to an industry which is regarded as one of the fastest globalizing industries in terms of market structure and production systems. In South Africa, companies have managed to develop skills in aviation manufacturing. The opportunities that will be created, owing to changes in global production chains, will enable South African companies to establish themselves further as global suppliers. The aviation industry contains high risks, especially because it is considered to be the industry which acts as a driver for innovation. Complexity of production, the capital-intensive nature and high risks involved in developing new products and services have linked the industry to inevitable political influence and support. The industry can broadly be divided into two main sectors: military and commercial. Analysts predict that opportunities in the global aviation markets in future will increase considerably. This is attributed to more Asian, African and Latin-American regions capitalizing on opportunities that exist mainly within the commercial sector. They will form strategic alliances which will enable them to perform on low-cost platforms and offer exceptional services to major players in the aviation sector. To capitalize on these opportunities, companies need to analyse their external and internal environment. The main objective of this study is to analyse and to evaluate the competitive environment of a selected aviation company, to ensure that the best strategy is chosen and adopted and to confirm that the company can create and sustain a competitive advantage over competitors. The planning tools utilized in this study are the PEST and SWOT analyses. Both have been used in the strategic planning process of many other firms. These analyses have proved to be the key element needed to formulate an action plan to be and to stay competitive in the aviation industry. This study evaluates both of these planning tools and applies them to the company chosen for this case study. / MCom (Management Accountancy), North-West University, Potchefstroom Campus, 2014

Aviation biofuel is technically viable and nearing the commercial stage. In the last 5 years aviation biofuel has moved from relative obscurity to become fully certified for commercial use in up to 50% blends with standard jet fuel. There have since been 15 successful commercial flight tests using aviation biofuels including Lufthansa s six month trial operating on a passenger revenue generating route in 2011. Airlines and biofuel companies such as British Airways and Solena are furthermore beginning to form partnerships to finance specialised aviation biofuel production facilities. However, aviation biofuels have yet to become widely commercialised. In fact, there are a series of issues preventing the emergence, development and uptake of aviation biofuels. The main issues are perceived as high costs of manufacture, limited availability of feedstocks, controversy surrounding the effect on food prices and the emissions output from land use change. Furthermore, there is a significant lack of academic peer reviewed literature which investigates these issues or offers solutions to support the development of the technology. This thesis aims to investigate the factors that affect the emergence, development and uptake of aviation biofuels by drawing upon in-depth stakeholder interviews and survey data. Strategic niche management (SNM) theory is used and extended to analyse the contemporary issues and develop recommendations to support the continued emergence, development and uptake of aviation biofuels. It is concluded that the emergence, development and uptake is being driven mainly by rising jet fuel prices, growing concern regarding aviation emissions legislation and fuel (in)security. Airlines, biofuel producers and specialised supply chain companies are driving emergence, development and uptake due to commercial opportunities. Despite these drivers, the emergence, development and uptake is being constrained by a combination of ineffective policy provision, high costs of production, limited feedstocks and uncertainty surrounding sustainability. Ineffective and unsuitable policy is exacerbating the issues of high production costs, limited feedstocks and sustainability. In particular, competition between aviation and road biofuels is limiting aviation biofuel expansion. Recommendations are to develop nurtured niche markets for aviation biofuels using principles from SNM. Within these markets, aviation biofuels are afforded commercial viability in order to learn about supply chain development, longer term infrastructural requirements and technological development. Information should be shared between the niche markets in order to maximise learning by doing and speed up efficiency gains. Once niche markets are established, the incentives and protection should be gradually reduced to allow a competitive aviation biofuel industry to develop.