Issues Related To Troubleshooting Of Avionic Hydraulic Units

The paper outlines workflows associated with troubleshooting of avionic hydraulic systems with detailed description of the troubleshooting algorithm and classification of diagnostic signals provided by avionic hydraulic systems and their subassemblies. Attention is paid to measurement sequences for diagnostic signals from hydraulic systems, circuits and units. Detailed description is dedicated to an innovative design of a troubleshooting device intended for direct measurements of internal leaks from avionic hydraulic units. Advantages of the proposed measurement method are summarized with benefits from use of the presented device and compared against the methods that are currently in use. Subsequent phases of the troubleshooting process are described with examples of measurement results that have been acquired from subassemblies of hydraulic systems of SU-22 aircrafts currently in service at Polish Air Forces with consideration given to cases when the permissible threshold of diagnostic signals were exceeded. Finally, all results from investigations are subjected to thorough analysis.