Risk Assessment for Urban eVTOL Operations and Air-Ground Cooperative Hazard Avoidance Mechanism

This study develops an eight-indicator framework for describing low-altitude operational risk and a candidate air-ground response architecture. The evidence is drawn from three distinct supplementary datasets: 1,000 source-labelled sortie records (772 retained after exposure and duration quality control; 740 operational and 32 simulated), a trajectory/alert slice aggregated to 123 occupied 500 m × 500 m by 5-min cells, and 6,079 occupied 5-min windows from 55 days of operational records. These datasets are analysed separately. In the 55-day series, the adjusted negative-binomial model estimated a rate ratio of 3.32 per one-level increase in mean sortie risk score (95% CI 3.13–3.52), while density had an independent rate ratio of 1.11 (95% CI 1.07–1.14). In the 700-cell trajectory pipeline, the score–alert association was not statistically distinguishable from unity (RR 1.0026 per point, 95% CI 0.9957–1.0095; p = 0.464). Near-perfect rolling-window AUCs were attributable to the close constructional dependence between sortie risk scores and event records and are not interpreted as independent predictive validation. Because the observations are low-altitude UAV operations and simulation records rather than commercial passenger eVTOL flights, the findings support a pilot assessment workflow, not eVTOL accident-risk estimates or validated operational thresholds.