In April 2006, an Unmanned Aerial Vehicle crashed near Nogales, Arizona. This incident is of interest because it triggered one of the most sustained studies into the causes of failure involving such a vehicle. The National Transportation Safety Board together with the US Customs and Border Protection agency under the Department of Homeland Security worked to identify lessons learned from this mishap. The crash at Nogales is also of interest because it illustrates an irony of Unmanned Aircraft Systems operations; the increasing reliance on autonomous and unmanned operations is increasing the importance of other aspects of human-system interaction in the cause of major incidents. The following pages illustrate this argument using an accident analysis technique, Events and Causal Factors charting, to identify the many different ways in which human factors contributed to the loss of this Predator B aircraft
