Cette recherche s’inscrit dans le domaine de la fiabilité des systèmes sociotechniques complexes, et vise à développer une nouvelle approche des arbitrages entre performance et sécurité : l’ingénierie de la résilience. La capacité des systèmes à risques à résister aux perturbations dépend, en dernière analyse, des acteurs de ces systèmes. Ceux-ci doivent réaliser des arbitrages entre des critères qui peuvent entrer en conflit : critères économiques immédiats (assurer la performance commerciale, par exemple), critères de sécurité (renoncer à satisfaire l’objectif immédiat de production). La thèse porte sur l’activité d’opérateurs d’une compagnie aérienne, en charge de répondre en temps réel à des appels d’équipages d’avions, qui signalent une complainte technique. Celle-ci peut-elle être traitée immédiatement : est-elle bénigne ou, au contraire, doit-elle conduire à l’annulation du vol concerné ? La thèse défendue est que, dans un système ultra sûr et ultra réglé, les conflits entre performance et sécurité se produisent lorsque la « sécurité gérée » rentre en conflit avec la « sécurité réglée ». Pour défendre cette thèse, trois études empiriques ont été mises en œuvre. Ainsi, plusieurs méthodes ont été utilisées en combinaison : l’observation et l’analyse de l’activité, la simulation d’activité, les questionnaires et les autoconfrontations.Les résultats obtenus ont permis, dans un premier temps, d’objectiver les arbitrages entre performance et sécurité, puis dans un second temps, d’identifier les critères qui président à ces arbitrages et d’expliciter les processus qui les sous-tendent. Ces résultats permettent, d’une part, de proposer des solutions acceptables telles que le retour d’expérience par la confrontation des pratiques, et d’assimiler la « sécurité gérée » comme un sous-ensemble de la « sécurité réglée », et d’autre part, de dépasser notre vision négative des violations, en les assimilant à une forme d’intelligence des opérateurs dans l’action. / This research is in the field of reliability of complex socio-technical systems and aims to develop a new approach to allow trade-offs between performance and safety: engineering resilience. The ability of systems to cope with disturbances ultimately depends on the operators of these systems. They must make trade-offs between criteria that may conflict: immediate economic criteria (i.e. to ensure business performance), safety criteria (i.e. give up to meet the immediate production objective). The thesis focuses on the activity of an airline’s operators, in charge of assistance via telephone for aircrew who report a technical complaint. It can be treated immediately; is it benign, or conversely should it lead to the cancellation of the flight?The thesis assumes that in an ultra-safe and ultra rule-based system, conflicts between safety and performance occur when the "rule-based safety" conflicts with "adaptative safety". To defend this thesis, three empirical studies have been implemented. Thus, several methods were used in combination: observation and activity analysis, simulation of activities, questionnaires and auto-confrontation.The results obtained allowed at first to objectify the trade-offs between performance and safety, then in a second instance to identify the criteria governing such trade-offs and explain the processes that underlie them.These results permit, on one hand, to propose acceptable solutions such as the feedback by comparing the practices and assimilate the “adaptative safety” as a subset of “rule-based safety”, and on the other hand to overcome our negative view of violations by treating them as a form of operators’ intelligence in action.

Cette étude est fondée sur deux constats dans le domaine de la maintenance aéronautique : l’utilisation non systématique de la documentation de maintenance aéronautique (DMA) malgré la prescription légale et l’évolution technologique qui a entraîné l’introduction de l’utilisation de l’appareil à petit écran ou mobile pour la consultation et la recherche d’information pour la réalisation de la tâche de maintenance. L’objectif de cette étude est double : identifier les raisons de la sous utilisation de la DMA et contribuer à la conception d’une documentation de maintenance adaptée à la fois aux supports mobiles (PDA), à l’utilisateur et au contexte de la maintenance aéronautique. Des tests d’utilisabilité ont été menés et testaient l’hypothèse selon laquelle l’utilisation du petit écran a un effet négatif sur les performances des utilisateurs. Des observations et entretiens dans les centres de maintenance ainsi que des tests sur avion ont aussi été conduits pour évaluer la lisibilité de l’interface et la portabilité des appareils mobiles. Les résultats montrent que les raisons de la non utilisation de la documentation de maintenance sont principalement liées à la non adaptation de celle-ci aux utilisateurs et au contexte du métier, que l’utilisation du petit écran est envisageable aussi bien pour une application destinée aux petits écrans que pour celle destinée aux écrans standard. En outre, l’utilisation du petit écran ne détériore pas, d’une façon générale, les performances des utilisateurs et qu’elle est envisageable aussi bien chez les novices que chez les experts qui sont encore réticents mais n’y sont pas opposés. / Literature review shows that maintenance operators do not use the aircraft maintenance documentation (AMD) systematically despite the legal obligation. The aim of this study is to contribute to the identification of users’ difficulty about the use of the AMD and the designing of maintenance documentation well-adapted to mobile devices (PDA), to users and to aircraft maintenance context. Hypothesis consists on verifying the effect of the small screen use on users’ performances. According to the usability test results, the small screen use has no negative effect on the users’ (experts and novices) performances. Field studies in maintenance centers and on aircraft show that small screen use is suitable to novices and experts for small screen documentation consultation and also for standard screen documentation when consultation is limited. Some users, particularly experts, are hesitant about using small screen for information consultation. However, they are not against the use of such format if information display is improved. Results are not limited to small screen documentation issue, some parts (e.g. information display study to reduce user effort) could be generalised to information system for task support.

This master thesis has the purpose to analyse and identify smart efficient future solutions within the Maintenance, Repair and Overhaul (MRO) process for aircraft. The efficiency solutions, in form of new technologies and tools, should present a foundation that MRO suppliers can continue to develop to enhance and streamline their maintenance processes. The project was performed as a case study at the aerospace and defense company Saab AB in Linköping, where the company's MRO process was investigated. Through identifying possibilities and alternative technologies available today and in the near future, one continues to have a competitive and future-proof position in the market.  Through an own constructed course of action influenced from established methods, the thesis' purpose and aim was attained. The method was based on authentic approaches for case studies but also inspired by the so-called "Requirement Engineering". The combination of the methods resulted in a precise focus on the relevant subjects, together with a clear structure of the requirements on the technologies to reach a successful implementation. Through a detailed data collection comprised of study visits, interviews, literature studies, market analyses, and document reviews, multiple relevant technologies and requirement-lists for utilization were identified.  To concretize the use and potential improvements with the technologies, the project had the objective to develop a demonstrator with one of the technologies presented. The demonstrator should focus on minimizing the use of paper, which is a common problem among many market actors today. The most promising technology was considered to be a tablet application with an accommodated application. The selection of the tablet solution was based on the motivation that it is a well-established technology and a favorable first step from paperwork.  To conclude this master thesis, a tablet application was developed in Novacura Flow Studio, where the majority of the identified requirements were fulfilled. Beyond the demonstrator, an introduction and analysis of technologies, such as AR-glasses, voice guidance, additive manufacturing, and a digital twin, was presented.

Aircraft maintenance training programs in the Air Force have evolved from an almost exclusively mechanical orientation to one that is largely electronic. The Armed Services Vocational Aptitude Battery (ASVAB) with its four selector composites (Mechanical, Administration, General, and Electronic) has been in use for over 20 years. The mechanical (M) composite score is used to identify those who will be trained in aircraft maintenance.

Thesis (M. of Military Art and Science)--U.S. Army Command and General Staff College, 2007. / The original document contains color images. Title from title page of PDF document (viewed on May 27, 2008). Includes bibliographic references.

Aircraft scheduled maintenance requirements are rapidly extending and developing due to rapid evolution of small aircraft. This evolution leads to implementation of until recently exclusively airliner class maintenance standards. In the field of general aviation and FAR 23/ EASA CS-23 especially, preventive maintenance based on part replacing or repairing is still dominant. DAMAGE TOLERANCE philosophy implementation into an aircraft design influences maintenance procedures, which are adjusted to older SAFE LIFE philosophy. Aircraft manufactures are developing new ways, how to integrate requirements of damage tolerance application into scheduled maintenance procedures. Huge airliner manufactures (FAR 25/ CS-25) are using the ATA MSG-3 intelligent maintenance approach based on inspection. This dissertation thesis develops intelligent scheduled maintenance methodology, utilizing ATA MSG-3 procedures, expert knowledge and Multiple Criteria Decision Analysis (MCDA).

The final thesis is focused on a project of a load bearing structure of a aircraft maintenance hangar that has a rectangular ground plan 60,0x120,0 m and includes suspended mobile hoist of loading capacity 5,0t. The object is situated in the airport area of Ostrava Mošnov. The task provides two versions of design. The first version consists of eleven traverse joining beams witch are distanced twelve meters from each other. The second version consists of thirteen traverse joining beams witch are distanced ten meters from each other. The thesis focuses on the load pressure of the steel construction, the main emphasis being placed on the single structural components and assembling components. The calculation meet the standards of ČSN EN.

This master’s thesis describes the area of operational suitability data that is established as part of the aircraft type certificate. The thesis first chapters are describing OSD, its origin and implementation. The thesis also analyzes all regulations that are connected with this matter and are focusing on the training of maintenance certifying staff. A part of this thesis deals with the description of aircraft Evektor EV-55 Outback, for which is created the educational material, and a description of its fuel system. The concept of educational material for maintenance certifying staff theoretical type rating training and an example of final test are at the end of the thesis.

Problemställning och syfte: Bromerade flamskyddsmedel (BFR) används i många varor och produkter. Polybromerade difenyletrar (PBDEs) är en av dessa och deras kemiska struktur liknar den i miljögiftet PCB och kan på samma sätt lagras upp i miljön samt skada människor och djur. På arbetsplatser där BFR förekommer riskerar medarbetarna att exponeras. I den här studien har olika BFR undersökts i samband med servicearbete på flygplan. Målet har varit att jämföra förekomsten i damm och luft, samt blod (serum) med resultat från tidi­gare studier. Metod: Damm- och luftprovtagning har genomförts vid olika faser av service­arbetet. Proverna har analyserats med avseende på olika typer av BRF. Dess­utom har medarbetarnas upptag av BRF via blodprov (serum) undersökts. Resultat: Undersökningen har visat att samtliga former av PBDE samt övriga BFR förekommer i höga koncentrationer i damm och luft i flygplanen, men med ojämn fördelning. Analyserna av serum visade att flygmekanikerna har förhöjda nivåer jämfört med svensk allmänhet och jämförbar nivå med högexponerade yrkesgrupper. Medarbetarnas ålder, år i yrke och arbetad tid i flygplan den senaste månaden uppvisade inget samband i förhållande till PBDE i serum. Slutsats: Koncentrationerna av BFR i damm och luft är högre än i de flesta andra miljöer och koncentrationerna i serum är högre än de flesta referens­gruppers. För att minska risken för exponering behöver insatserna för att mini­mera dammet via städning förbättras. Dessutom bör informationen gällande hygien och användning av personlig skyddsutrustning repeteras för medarbe­tarna. Samtliga yrkeshygieniska åtgärder bör fastställas och hanteras i det systematiska arbetsmiljöarbetet via rutiner och handlingsplaner. / Presentation and aim: Brominated flame retardants (BFRs) are used in many materials and products. Polybrominated diphenyl ethers (PBDEs) are the most well known and because of their structures, similar to that of PCB, they have been proposed to possibly affect health and environment. Occupational exposure has been an issue for years and this study investigated BRF in aircraft mainte­nance. The aim of this study was to assess the presence and levels of BRFs in dust, air and blood (serum) and compare the results with different references. Method: Dust and air were sampled in different phases of the work with the air­craft and analysis of a spectrum of BFR was performed. In addition, serum from employees was sampled and analyzed for the presence of PBDEs. Result: PBDEs and other BFRs were found in dust and air samples at high con­centrations. Serum concentrations in the technicians were slightly higher to those observed in the general Swedish population and in the same magnitude as some highly exposed occupational references. Years of work, age or time spent in the aircraft before giving blood seems not to have an impact on the level of BFRs in serum. Conclusion: This study shows high concentrations of BFR in dust and air in the aircraft and the concentrations of PBDEs in serum were high compared to most reference groups. To minimize the risk for exposure, it is important to focus on industrial hygiene improvements to minimize the amount of dust in working areas. The personal hygiene and use of personal safety equipment can also be improved and the routines should be described and included in the appropriate documentation regarding work environment.

In aviation, great emphasis is placed on aircraft safety. The current technical condition of the aircraft and its systems is an important parameter for its airworthiness. The technical condition of the elements measured during the flight should be compared to parameters specified by the manufacturer and measured in laboratory conditions. This thesis deal with the possibilities of the use of dimensionless numbers for the diagnostics of the hydrogenerator and deals with the diagnostics possibilities of selected elements.