The aim of this paper is the presentation of a novel methodology for risk assessment applied to different RPAS with a MTOM lower than 25 kg, also including lighter-than-air configurations. This methodology concerns with ground impacts and does not cover the aspects of mid-air collisions. The results of this analysis provide a comprehensive insight for mission feasibility and operational implications in a set of realistic application cases. Practical solutions are proposed for risk mitigation of RPAS operations enforcing a concept of general validity, also compliant with forthcoming common EU regulations, applicable at continental level.