ABSTRACT
Every age has a dawning. In the maritime world, Mr Justice Sheen's judgement on the causes of the capsize of the Herald of Free Enterprise represents one such marker. Mter acknowledging the shipboard (or active) errors of the Master, the Chief Officer and the Assistant Bosun, he wrote:
But a full investigation into the disaster leads inexorably to the conclusion that the underlying or cardinal faults lay higher up in the Company ... From top to bottom the body corporate was infected with the disease of sloppiness. (Sheen, 1987)
In aviation, we are indebted to Commissioner Moshansky's inquiry into the crash at Dryden, Ontario, perhaps the most exhaustive investigation ever undertaken into an aircraft accident. On the face of it, the accident was due to the Captain's flawed decision to take off in
a heavy snow squall without de-icing protection from ground contamination. But Commissioner Moshansky interpreted his brief more widely. Introducing his findings, he wrote:
The accident at Dryden on March 10, 1989, was not the result of one cause but of a combination of several related factors. Had the system operated effectively, each of the factors might have been identified and corrected before it took on significance. It will be shown that this accident was the result of a failure in the air transportation system. (Moshansky, 1992)
The main purpose of this chapter is to outline a theoretical framework that seeks to provide a principled basis both for understanding the causes of organizational accidents and for creating a practical remedial toolbag that will minimize their occurrence. This framework traces the development of an accident sequence from organizational and managerial decisions, to conditions in various workplaces (flight decks, hangars, etc.), and thence to the personal and situational factors leading to errors and violations. It identifies both an active and a latent failure pathway to an event, where an event is defined as the breaching, absence or bypassing of some or all of the system's various defences and safeguards. Such an event may have disastrous consequences or it may merely serve as a 'free lesson'. The outcome depends upon the local circumstances and how many of the defences-in-depth are removed.
