Proximate Events

The next section contains a description of the proximate events involved in the loss. Then the STAMP analysis providing an explanation of why these events occurred is presented. 

After receiving a briefing on the day s mission, the AWACS took off from Incirlik Air Base. When they arrived on station and started to track aircraft, the AWACS surveillance section noticed unidentified radar returns (from the Black Hawks). A friendly general track symbol was assigned to the aircraft and labeled as H, 

John Shalikashvili, chairman of the Joint Chief of Staff, from a cover letter to the twenty-one-volume report of the Aircraft Accident Investigation Board, 1994a, page 1. 

0545 AWACS declares on Station. Surveillance section begins tracking a/c  

0616 H character programmed to appear on senior director s scope vtrhenever Eagle Flight s IFF Mode 1, Code 42 is detected.  

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FRET (fluorescence resonance energy transfer) Several Proximity event measured by radiationless energy transfer between donor and acceptor fluorophores followed by photon emission by the latter... 

Event chains developed to explain an accident usually concentrate on the proximate events immediately preceding the loss. But the foundation for an accident is often laid years before. One event simply triggers the loss, but if that event had not happened, another one would have led to a loss. The Bhopal disaster provides a... 

At least three types of factors need to be considered in accident causation. The first is the proximate event chain, which for the Herald of Free Enterprise includes the assistant boatswain s not closing the doors and the return of the first officer to the wheelhouse prematurely. Note that there was a redundant design here, with the first officer checking the work of the assistant boatswain, but it did not prevent the accident, as is often the case with redundancy [115,155]. 

An accident model should encourage a broad view of accident mechanisms that expands the investigation beyond the proximate events A narrow focus on operator actions, physical component failures, and technology may lead to ignoring some of the most important factors in terms of preventing future accidents. The whole concept of root cause needs to be reconsidered. 

Part of the problem stems from the use of the chain-of-events model in accident investigation because it is difficult to find an event preceding and causal to the operator behavior, as mentioned earlier. If the problem is in the system design, there is no proximal event to explain the error, only a flawed decision during system design. 

Figure 5.4, taken from the official Accident Investigation Board Report, shows a timeline of the actions of each of the main actors in the proximate events—the AWACS, the F-15s, and the Black Hawks. It may also be helpful to refer back to figure 5.1, which contains a map of the area showing the relative locations of the important activities. 

When looking only at the proximate events and the behavior of the immediate participants in the accidental shootdown, the reasons for this accident appear to be gross mistakes by the technical system operators (the pilots and AWACS crew). In fact, a special Air Force task force composed of more than 120 people in six commands concluded that two breakdowns in individual performance contributed to the shootdown (1) the AWACS mission crew did not provide the F-15 pilots an accurate picture of the situation and (2) the F-15 pilots misidentified the target. From the twenty-one-volume accident report produced by the Accident Investigation Board, Secretary of Defense William Perry summarized the errors, omissions, and failures in the chain of events leading to the loss as ... 

Unit 7 was previously used to manufacture pesticide, but production was moved to Mexico because it was cheaper to make there. At the time of the start of the accident proximal events. Unit 7 was shut down and was not being used. It was restarted to provide extra K34... 

In May 2000, in the small town of Walkerton, Ontario, Canada, some contaminants, largely Escherichia coli 0157 H7 (the common abbreviation for which is E. coli) and Campylobacter jejuni entered the Walkerton water system through a municipal well. About half the people in the town of 4,800 became ill, and seven died [147], The proximate events are presented first and then the STAMP analysis of the accident. 

Investigators view of air proximity events also provides an illustration of how much emphasis is placed on all organisational activities remaining within a safe and controlled zone of operations. Air Traffic Control processes that aim to maintain five-miles clearance between aircraft can be found lacking by investigators - even without any actual... 

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