Skill-based error accidents were the most prevalent, followed by decision error accidents, in an analysis of accidents in Alaska, U.S., involving fatality or serious injury.1 But those that involved rule violations were the most deadly.
The accidents — which involved airplanes and helicopters — were categorized by researchers according to the Human Factors Analysis and Classification System (HFACS) devised by Douglas Wiegmann and Scott Shapell. The full HFACS taxonomy includes a hierarchy of four levels, but for this study only the lowest level, “unsafe acts,” was used. That in turn was subdivided into skill-based error, perceptual error, decision error and violations.
The study analyzed 97 accidents occurring from 2004 to 2009. Of those, 55 involved aircraft flown under U.S. Federal Aviation Regulations Part 91, General Operating and Flight Rules; 18 involved Part 91 flights in business use, designated by the research…
