Acoustic emission (AE) method is a contemporary and perspective method for aircraft structural assemblies and non-destructive inspection and technical monitoring of the condition. One of the most important diagnostic methods in AE technological operations is structural health monitoring operation and determination of the AE source coordinates. Is offered developed AE signal amplitude based theoretical model which is proved to be useful not only for defect coordinate determination, but also crack growth and operation analysis. The study focuses on structural health monitoring methodology for defect localization on helicopter tail fatigue test bench. Measurements were made on the helicopter fuselage – the sound velocity and AE signal amplitude measurements were made on the plating taking into account fuselage internal framing – stringers and frames. Attenuation of AE signal amplitude and its relationship to AE source location – distance and relative to the AE sensor was obtained.