typically have no training in human factors or in aviation, forensic human factors experts specializing in aviation are needed to analyze, explain, and give probabilistic opinions, so that judges and juries can make informed decisions. Although litigation is considered by many as a negative, a positive outcome may be to help prevent further occurrences.
An airplane crashes and someone dies. Federally mandated investigations are launched to determine the probable cause(s) and to uncover any regulatory violation(s). Recommendations for rule changes or penalties may follow. These are prospectively aimed at preventing similar mishaps. Civil legal actions may also follow but are more retrospective as they look for specific blame and seek compensation for losses.
Both avenues, governmental and civil, pursue recourses/remedies but from different perspectives. Governmental investigations are typically public, fact finding, and directed at categorical reporting and statistical manipulation. Usually only recurrent accidents evoke response to the underlying issues in question, human or machine, and then only after there is some general consensus that a fix is needed and proper.
Civil actions, however, are typically private, cloistered, argue the meaning of specific facts already known, and focus on alleged errors. The very adversarial nature of the "civil" process places the individual pilot and system(s) under extreme scrutiny to force justification of their respective actions and design. As each matter is settled either by mediation or by verdict, the precedent becomes a deterrent for similar incidents.
Taken in tandem, both approaches provide real-world feedback about practical human factors issues, with regard to the merits of a system design and its use. Clearly, these postcrash analyses are the last resort, coming too late for those involved, but are preferable to inaction if a real problem exists.
Government agencies do have the weight of law behind mandated changes, but must wait to amass statistical evidence and to make a persuasive case concerning the relatedness of what appear to be similar crashes. The process of proposed rule making has to overcome many checks and balances designed to guard against unnecessary fixes or unwanted regulation that might arise from a truly isolated mishap, that is, a sampling error.
Civil lawsuits, on the other hand, evaluate single cases, but carry no regulatory authority. Indeed, the fact that many final judgments in civil lawsuits do not eventually become law suggests governmental dismissal of the cause as an act of God or as a unique event generally unlikely to reoccur (e.g., preventable carelessness). It is also possible that there were flaws in the final judgment because of a lack of knowledge or distortion of the meaning of facts about aviation or human factors. The extent to which the judgment was valid, yet not made regulatory, may serve as warning to designers and users alike that certain actions or inaction may carry the added risk of penalties.
Human factors experts in aviation can assist in all these processes, from postcrash analysis and through recommended remedies. However, because it is the civil legal system that most often (vs. government agencies) retains human factors experts for aviation forensic services, this chapter focuses primarily on civil proceedings in an attempt to provide the reader with an understanding of the issues involved.