The main objective of early impact analysis after a disaster is to produce georeferenced data about the affected areas, in support of humanitarian action. Crucial information are the identification of the hitten areas and the estimation of the number of people involved. Satellite imageries are mainly used as input data for early impact analysis at small and medium map scale (ie floods events). Analyses aimed at defining the damages to infrastructures and/or to facilities (ie earthquakes) require suitable data for large scale analyses, as far as high resolution satellite images. Unfortunately, such images are not always available in a few days after the event, therefore in situ surveys are preferred. ITHACA (Information Technology for Humanitarian Assistance, Cooperation and Action)-a non profit association with the main goal to carry on operational and research activities in the field of geomatics for analysis, evaluation and mitigation of natural and manmade hazards-is developing a low cost mini UAV (Unmanned Aerial Vehicle) devoted to the early impact analyses. The aim of the UAV project is to develop a low cost aerial platform capable of autonomous flight and equipped with a photogrammetric payload for rapid mapping purposes. The main requirements for this type of UAV are to be easily transportable and usable on the field, autonomously, by a couple of operators. Therefore, it was decided to customise the MH2000 platform designed and patented by the Department of Aerospace Engineering (DIASP) of the Politecnico di Torino. The current configuration of the UAV allows to carry onboard digital sensors for video and imagery acquisition. The sensors are mounted in a pod placed on the belly of the fuselage, that can be remotely controlled through a direct link to the autopilot board that allows to schedule automatic acquisitions at defined time intervals or planned positions. A real-time video downlink of the overpassed areas is provided. Several test flights were performed in order to set up the control parameters of UAV and to analyse the capability of performing autonomous flights according to the defined flight-path. Two photogrammetric surveys aimed at calculating the achievable 3-D accuracy have been peformed over a flight centre and an archaeological site (both located in Italy). Results of both tests will be shown in detail.