The purpose of the activity is the definition of a detailed guideline based on theoretical and experimental criteria, for the evaluation of the offensiveness and the consequent certification of remote piloted aircraft systems (drones) with take-off mass of less than 25 kg. The SAPR (Remote Pilot Aircraft Systems) sector is considered as one fields with greater development prospects, both in the military and in the civil field. At present, the main barriers of entry are constituted not by technological factors, but rather by intrinsic safety and safety requirements security. In particular regarding safety (safety), knowledge about the danger of impacts of SAPR on the human body are totally lacking ("Human Injury Model for Small Unmanned Aircraft Impacts", Civil Aviation Safety Authority, Australia, 2013). From the most recent and reliable market surveys ("Study on the Third-Party Liability and Insurance Requirements of Remotely Piloted Aircraft Systems (RPAS) ", European Union, 2014), results that most commercial civil operations are carried out with APR light, below 25 kg, and within this band, the ultra-light APRs, ie below 7 kg, are predominant (from 80% to 90%). The rules ENAC article 12 paragraph 1, provides a substantial exemption for all specialized operations conducted in all operating scenarios with operating mass SAPR at take-off of less than or equal to 2 kg provided the aspects design and construction techniques of the APR have characteristics of inoffensiveness, previously ascertained by ENAC or by a subject authorized by it. The research project aims to develop the cognitive, theoretical and the bases experimental, necessary to characterize the effects on the human body in an objective, reproducible and meaningful way the impacts of these "harmless" SAPR categories.