Despite the use of high safety standards in aircraft design and operations, accidents do occur. In a process of continuous improvement it is essential that we learn from each accident so we can take measures to prevent such accidents from happening in the future. It is often the case that an accident is the result of a sequence of, seemingly minor and often unrelated, events. The challenge is to identify the major causes, which can include deficiencies in organisational processes which may have been present well before the accident itself. This paper discusses tools which can be used to identify key organisational factors which contribute to aviation accidents. The research uses a thoroughly-investigated helicopter accident as a case study, to determine the extent to which analytical and visualisation tools can be used to assess maintenance organisational issues which contributed to the accident.