Subjectivity in Selecting the Chaining Conditions

In addition to subjectivity in selecting the events and the root cause event, the links between the events that are chosen to explain them are subjective and subject to bias. Leplat notes that the links are justified by knowledge or rules of different types, including physical and organizational knowledge. The same event can give rise to different types of links according to the mental representations the analyst has of 

Consider, for example, the loss of an American Airlines B757 near Cali, Colombia, in 1995 [2], Two significant events in this loss were 

In fact, the pilot should have typed the four letters ROZO instead of R—the latter was the symbol for a different radio beacon (called romeo) near Bogota. As a result, the aircraft incorrectly turned toward mountainous terrain. While these events are noncontroversial, the link between the two events could be explained by any of the following  

An FMS is an automated flight management system that assists the pilots in various ways. In this case, it was being used to provide navigation information. 

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