The tutorial provides basic concepts and definitions in the field of designing electronic modules of the second and third levels of the construction hierarchy. General information on bearing structures of avionics equipment, their varieties and materials used for their manufacture is given. The requirements for the layout of avionics equipment units, the tasks of designing intra- and interunit electrical connections, the problems of ensuring mechanical stability and normal thermal modes of avionics equipment are considered. Peculiarities of avionics equipment structures for various purposes are given.