High-reliability advocates claim that highly reliable organizations (HROs), such as the Federal Aviation Administration's (FAA) air traffic control system, routinely demonstrate the ability to safely and reliably perform large-scale technical operations. High levels of productivity with low levels of error are achieved even though complex technologies are used to accomplish mission goals. A recent study asserted that the FAA’s air traffic control function developed HRO characteristics over a long period of time as part of a larger high-reliability system. In that study, identifiable and measurable attributes and characteristics associated with high reliability were constructed, and their emergence was tracked over time. In this article, time-series analysis was used to measure the relationship between characteristics associated with high reliability and commercial aviation accident reduction. A small but statistically significant effect was identified linking the adoption of HRO characteristics over time with a reduction in commercial aviation accident rates.