An acoustical diagnostics model of composite shells for aircraft systems is proposed. The peculiarity of this model emerges from taking into account shell anisotropical properties. On this basis, the decision to use a method of structure breach in the pipe line is proposed. Peculiarities that are bound up with pipe-line constructions and determine natural resonances and antiresonances are noted. By excitation of surface waves it becomes possible to identify the presence of shell norms and destruction. Qualitative corroboration of sound-speed change effect in the composite shell is obtained. It allows one to prognosticate the state of pipe-line aircraft systems.