Human related accidents in high-risk industries amount to a significant economic hazard and incur tremendous damages, causing excessive operational costs and loss of life. The aviation industry now observes human-related accidents more frequently than in the past, an upswing attributable to cutting-edge technology usage and the complex systems employed by aviation organizations. Historically, aviation accidents have been attributed to individual unsafe behavior. However, contemporary accident causation models suggest that organizational-level factors influence individual safety performance, as human-related accidents take place in an organizational context. The present study examines the formation of organizational safety culture and influence on individuals' safety behavior in a police aviation environment. The theory of planned behavior guides the study model in explaining individual variability in safety behavior via organizational safety culture. The study conceptualized organizational safety culture and individual safety behavior as multidimensional constructs. Confirmatory factor analysis was conducted for each latent construct to validate the construct validity for each measurement model. Organizational safety culture was observed via safety climate facets, which contained four subcomponents including individual attitude, group norms, management attitude, and workplace pressures. Individual safety behavior contained violation and error components observed by self-reported statements. Structural equation modeling was conducted to test the study hypotheses. Utilizing a sample of 210 employees from the Turkish National Police Aviation Department, a 53-item survey was conducted to measure individuals' safety culture perceptions and self-reported safety behaviors. The results suggest that individual safety behavior is significantly influenced by organizational safety culture. Except for the relation between workplace pressures and intention, all suggested relations and correlations were statistically significant. The four-factor measurement model of organizational safety climate fit reasonably well to the data, and most correlations between the safety climate components were significant at the .05 level. Individuals' self-reported error behavior is positively associated with age, and individuals' self-reported violation behavior is positively associated with years of service. Overall, along with organizational safety culture, age and service-year variables accounted for 65% of the variance in intention, 55% of the variance in violation behavior, and 68% of the variance in error behavior. Lastly, no significant difference manifested among pilots, maintenance personnel, and office staff according to their self-related safety behaviors. The findings have theoretical, policy, and managerial implications. First, the theory of planned behavior was tested, and its usefulness in explaining individuals' safety behavior was demonstrated. The survey instrument of the study, and multi-dimensional measurement models for organizational safety climate and individual safety behavior were theoretical contributions of the study. Second, the emergence of informal organizational structures and their effects on individuals indicated several policy implications. The study also revealed the importance of informal structures in organizations performing in high-risk environments, especially in designing safety systems, safety policies, and regulations. Policy modification was suggested to overcome anticipated obstacles and the perceived difficulty of working with safety procedures. The influences of age on error behavior and years of service on violation behavior point to the need for several policy modifications regarding task assignment, personnel recruitment, health reports, and violation assessment policies. As well, managerial implications were suggested, including changing individuals' perceptions of management and group attitudes toward safety. The negative influence of anticipated obstacles and the perceived difficulties of safety procedures on individual safety behavior pointed out management's role in reducing risks and accidents by designing intervention programs to improve safety performance, and formulating proactive solutions for problems typically leading to accidents and injuries.

La thèse s’intéresse au travail de conduite d’une industrie de process à risques,les centrales nucléaires, et aux marges de manoeuvre dont disposent les équipes dans l’application des procédures techniques. Celles-ci doivent en effet être adaptées aux situations rencontrées dans la réalité, qui sont toujours nouvelles et finalement uniques. En effet, la technologie concernée est si complexe que les situations ambiguës sont fréquentes. Les exploitants sont souvent confrontés à des décisions techniques qui cristallisent en elles la pluralité d’exigences auxquelles sont soumises les industries à risques : sûreté nucléaire, disponibilité et productivité, sécurité des travailleurs, respect de l’environnement, etc.Exploiter une centrale nucléaire implique donc d’arbitrer entre des exigences qui devraient en théorie être conciliables mais qui ne le sont pas en pratique, ou difficilement. En effet, chaque terme de la décision concrète comporte des avantages vis-à-vis de l’un des critères et des inconvénients vis-à-vis des autres critères en présence. Ainsi, décider revient toujours à renoncer, et la décision technique dans les organisations à risques implique une prise de risque professionnelle et personnelle pour les acteurs de terrain. La thèse s’interroge alors sur les facteurs qui participent de l’engagement des opérationnels dans l’action. Les théories utilitaristes et culturalistes ne parvenant pas à épuiser toute la complexité des cas rencontrés (implication d’agents pourtant peu carriéristes, disparités individuelles fortes au sein de groupes socio-professionnels supposés homogènes. . .), la recherche s’intéresse aux théories de la reconnaissance sociale et du don/contre-don comme explication première de la motivation et de la coopération au travail. / This doctoral dissertation describes the running of a high-risk process industry,nuclear power plants, and the operators’ autonomy to apply technical procedures.The chosen procedures must fit the "real-life" situations, which are always new, andultimately unique. Nuclear power technology is so complex that ambiguous situations often arise. The operators have to make technical decisions that encompassall the demanding issues of high-risk industries : nuclear safety, plant availabilityand generation output, workers’ safety, environmental protection, etc.Operating a nuclear power plant thus involves trade-offs between theoretically compatible concerns that in practice are incompatible or difficult to reconcile.Each option in the actual decision will have advantages for certain criteria anddisadvantages for others. Deciding thus always means forgoing something, andtechnical decision-making in high-risk organizations forces the field workers totake professional and personal risks. The dissertation thus examines the factors explaining why operators are still interested in getting involved in the action.Self-interest and cultural theories cannot explain all the cases encountered in thefield (workers with high commitment but paradoxically little interest in career advancement, strong differences between individuals in a supposedly homogenoussocio-professional groups, etc.). The research focuses on social recognition andgift/countergift theories as the primary explanation for motivation and cooperation at work.