BACKGROUND
A primary tool for evaluating fielded systems is to review mishaps. This study is a 10-yr cross-sectional quantitative analysis of the distribution and determinants of operator error in remotely piloted aircraft (RPA) mishaps within the U.S. military services using a standardized human factors taxonomy and a hierarchical model of human error.
METHODS
Data on RPA mishaps during fiscal years 1994-2003 were obtained from the Air Force, Army, and Navy/Marines safety centers. Mishap reports were reviewed and human factors coded using the Department of Defense's Human Factors Analysis and Classification System (HFACS). Binary logistic regression was used to create models predicting operator error.
RESULTS
A total of 221 mishaps were identified, of which 60.2% involved operations-related human causal factors. The frequency of human factors mishaps was 79.1%, 39.2%, and 62.2% for the Air Force, Army, and Navy/Marines, respectively. Latent failures at the organizational level were most prevalent and were associated with both operator error and mechanical failures. Predictors of operator error were technological environment and cognitive factors in the Air Force; organizational processes, psycho-behavioral factors, and crew resource management in the Army; and organizational processes, inadequate supervision, planned inappropriate operations, physical and technological environments, and cognitive and psycho-behavioral factors in the Navy. The frequency of specific types of errors differed between the services with skill-based errors more common in the Air Force and violations in the Army.
CONCLUSION
Recurring human factors failure at the organizational, supervision, preconditions, and operator levels have contributed to more than half of RPA mishaps.