We considers the organization of a subsystem for collecting diagnostic information about railway signaling and interlocking devices using unmanned aerial vehicles (UAVs) with a payload. An expanded architecture for the system of technical diagnosis and monitoring of railway signaling and interlocking equipment has been developed. Principles for ensuring the safety of measurement operations using UAVs have been discussed. A method for forming an overflight over route for UAV is proposed, considering the features of diagnosis objects and the specifics of the arrangement of railway infrastructure. Based on the analysis, work on manual technical diagnosis that is automated using UAVs has been highlighted. Many defects in trackside devices of railway signaling and interlocking have been identified, which distinguished by unmanned aerial vehicles. The use of the solutions proposed by the authors makes it possible in practice to expand many automatically recorded diagnostic events, as well as to reduce the period of diagnosis. This helps to maintain a high level of reliability and readiness of railway signaling and interlocking devices.