The article describes the development of an onboard information collection system for calculating the aerodynamic characteristics of unmanned aerial vehicles (UAVs), which can only be obtained under free flight conditions. A functional diagram is presented, a flight parameters registration system operation algorithm is described. The proposed so-lutions make it possible to collect a large amount of information and improve system efficiency through the selection and compression of information. The collected information is used to determine the aerodynamic characteristics, eliminating the need to test UAVs models in wind tunnels, which can save money and time on the development of new UAVs. The features of the information exchange between the system elements are considered, which make it possible to speed up the data transfer, and therefore improve the accuracy of measurements by increasing the frequency of polling measuring devices. The results obtained may be of interest to developers of autonomous measuring systems. Of particular importancce for calculating the aerodynamic characteristics of an UAV using the proposed method is the high accuracy of measuring the parameters of the aircraft trajectory, including the linear accelerations and angular velocities that occur in the course of motion. In addition, the article considers a variant of the hardware implementa-tion of the proposed system for UAVs.