Human Error and the Failure of Imagination: A Preface to HESSD

There is little room for complacency. For example, it has been difficult to sustain reductions in the incident rate across the aviation industry. This not only indicates an impasse in attempts to achieve ‘zero’ accidents. It is also a source of long-term concern because a stable incident rate combined with rising numbers of departures will yield increases in the frequency of adverse events. In other areas, the incident rates are rising in spite of the best efforts of safety managers. For instance, the frequency and rate of serious accidents in the US Army declined steadily in the decade prior to 2000. However, since that time there has been a rise in the number of soldiers killed or seriously injured by these adverse events. The nature of military operations has changed over this interval. Not only have operations in the Middle East increased risk exposure but the changing technology used by personnel has also affected the nature of many adverse events. In May 2003, Defense Secretary Rumsfeld focused concern: "Worldclass organizations do not tolerate preventable accidents. Our accident rates have increased recently, and we need to turn this situation around”. He set the challenge to "to reduce the number of mishaps and accident rates by at least 50% in the next two years”.