Abstract
Small unmanned aerial vehicles (drones) are increasingly utilized across various fields, including
agriculture, logistics, aerial photography and disaster surveys and management. However, the number of
drone-related accidents continues to rise each year, highlighting the need for the establishment of effective
safety measures. The lack of systematic analysis of accident causes can be one of the prime reasons for
this trend. In this study, we analyzed the current state of drone accidents in Japan using H.F. Hawkins’
SHEL model, which is widely used in human-error analysis. Based on the results of the analysis, we
developed a new accident analysis model specifically designed for drones, called the S-SHOELR model.
The model incorporates the traditional SHEL framework with two additional analysis elements-Safety
and Radio wave (communication)̶while clearly distinguishing between Operators and Liveware (related
personnel). The S-SHOELR model is not only useful for accident analysis but also applicable to risk
assessment and operator training, contributing to the safer operation of drones.
