In the wake of several highly-publicized aviation accidents in the past ten years, the use of Probabilistic Risk Analysis (PRA) for safety-related operational and design decisions has gained significant momentum and acceptance in civil aviation. Research studies in the field of aviation have highlighted some of the contributing factors of accidents, but there is no comprehensive model tracing the paths of influence starting from the root organizational factors up to the accidents and/or incidents. This paper uses a framework called Socio-Technical Risk Analysis (SoTeRiA), which is an extension of PRA, in order to develop a safety causal model for air carrier maintenance. The proposed aviation safety causal model covers a broad range of influencing factors including the physical and human aspects of the systems as well as their organizational and regulatory environments. This resulting model, through proper integration with models of the technical systems, will help manage risks proactively, based on leading indicators in the safety-related practices of the organization, and relevant regulatory activities and oversight.