The basic tenet of this paper is that today’s national airspace systems, at least in advanced industrial countries, qualify as so-called Highly Reliable Systems (HRS). In an HRS, even the type of accident that causes the most fatalities is a rare event. This means that in an HRS, the avoidance of accidents is a frequent event. Therefore, the best way to improve an already highly reliable system would be to learn from the cases where accidents have been avoided. This is not possible, however, because you can’t learn from what is unknown. Instead, safety managers resort to retrospective analyses of the most deadly accidents overall. In an unreliable system, it makes sense to correct what is wrong. In an HRS, however, any mitigation efforts that arise from rare, unpredictable, and often unique events carry great danger to upset the balance of the HRS. Such interventions must be scrupulously vetted, in a series of steps that become increasingly costly as the series progresses. This paper makes some suggestions for these steps. If the anticipated benefit from the intervention is not worth the cost of such a thorough review for unintended consequences, then it may be better to accept the existing high reliability of the system as good enough and leave the system unchanged.
Controlled Flight into Terrain (CFIT) crash is defined as an unintentional collision with terrain (the ground, a mountain, a body of water, or an obst...
The Human Factors Analysis and Classification System (HFACS) is a theoretically based tool for investigating and analyzing human error associated with...
Links with this icon indicate that you are leaving a Bureau of Transportation
Statistics (BTS)/National Transportation Library (NTL)
Web-based service.
Thank you for visiting.
You are about to access a non-government link outside of
the U.S. Department of Transportation's National
Transportation Library.
Please note: While links to Web sites outside of DOT are
offered for your convenience, when you exit DOT Web sites,
Federal privacy policy and Section 508 of the Rehabilitation
Act (accessibility requirements) no longer apply. In
addition, DOT does not attest to the accuracy, relevance,
timeliness or completeness of information provided by linked
sites. Linking to a Web site does not constitute an
endorsement by DOT of the sponsors of the site or the
products presented on the site. For more information, please
view DOT's Web site linking policy.
To get back to the page you were previously viewing, click
your Cancel button.