Inter-Organizational Safety Debate: The Case of an Alarm System from the Air Traffic Control Domain

Background

In the Western world, every transport accident is followed by an investigation carried out by a Safety Board whose aim is not to identify “legal” responsibilities but to identify areas where operations could be improved. The present study focuses on the debate developed around safety recommendations following an accident involving aircraft flying into terrain or hitting an obstacle. We shall outline a general framework for analyzing accidents with a focus on safety issues.

The analysis of an accident should be informed by four dimensions including the cover story, the targets of the hazards, in our case human life and technical equipment, the nature of the hazard, in our case the spatial and temporal relationship between aircraft and obstacles, and the control strategy which can address one or more of the phases characterizing the adverse event. Such event or rather “flow of effects” can be causally linked to at least three preceding conditions: the root cause, the casual chain, the critical event itself. Safety control depends on means to break or to deviate the flow of events leading to the accident. A consensus should ideally be reached among decision makers at all levels of the socio-technical system with respect to the hazard sources and their control requirements. Following the representation of the accidental event, two main strategies can be identified: either blocking those events close to the critical ones or stepping backwards towards the “root causes” (Rasmussen et al., 2000).

Given a simplified representation of a sequence of events leading to an accident (Table 1), the following represents a schematic view of events in the worst scenario of Controlled Flight Into Terrain (CFIT).