Quantifying risk of ground impact fatalities of power line inspection BVLOS flight with small unmanned aircraft

One of the major challenges of conducting operation of unmanned aircraft, especially operations beyond visual line-of-sight (BVLOS), is to make a realistic and effective risk assessment. An important part of such an assessment is to identify the risk of fatalities, preferably in a quantitative way since this allows for comparison with manned aviation to determine whether an equivalent level of safety is achievable. This works presents a method for quantifying the probability of fatalities resulting from an uncontrolled descent of an unmanned aircraft conducting a BVLOS flight. The method is based on a standard stochastic model, and employs a parameterized high fidelity ground impact distribution model that accounts for both aircraft specifications, parameter uncertainties, and wind. The method also samples the flight path to create an almost continuous quantification of the risk as a function of mission flight time. The probability of fatality is determined for a Talon model aircraft on a power line inspection mission.