Understanding the Contribution of Degraded Modes of Operation as a Cause of Incidents and Accidents in Air Traffic Management

摘要

This paper charts the role that 'degraded modes of operation' have played in a number of recent accidents and incidents in European Air Traffic Management. A central aim of this analysis is to begin to understand why teams of co-workers continue to operate safety critical systems even when key elements of their technological infrastructure have been compromised, for example during routine maintenance. There is often a culture of 'making do' where managers and staff try their best to maintain services. The extent to which workers will adapt to degraded modes illustrates the flexibility and resilience of socio-technical systems. However, it can also endanger safety when infrastructure changes act to increase workload or remove necessary 'safety nets'. It is hoped that by studying previous incidents and accidents, we may ultimately help operators and managers understand the dangers of degraded modes of operation while at the same time supporting the flexible working practices that are necessary in many complex, safety-critical systems.