This paper discusses a model of the civil aviation reg-ulation framework and shows how the current assess-ment of reliability and risk for piloted aircraft has a limited applicability for Unmanned Aircraft Systems (UAS) as technology moves towards higher levels of autonomous decision making. Then, a new frame-work for risk management of robust autonomy is pro-posed, which arises from combining quantified mea-sures of risk with normative decision making. The term Robust Autonomy describes the ability of an au-tonomous system to either continue or abort its oper-ation whilst not breaching a minimum level of accept-able safety in the presence of anomalous conditions. The term combines reliability, safety, and robust-ness. The decision making associated with risk man-agement requires quantifying probabilities associated with the measures of risk and also consequences of outcomes related to the behaviour of autonomy. The probabilities are computed from an assessment under both nominal and anomalous scenarios described by faults, which can be associated with the aircraft's ac-tuators, sensors, communication link, changes in dy-namics, and the presence of other aircraft in the op-erational space. The consequences of outcomes are characterised by a loss function quantifies the desir-ability of the outcome
