This work considers fatigue strength behavior of construction made from composite materials. Primary attention in this work is focused to fatigue strength behaviors of helicopter tail rotor blade made from composite materials. To analyze fatigue strength behavior of composite blade here the blade tested under static and fatigue load spectrum. For precise definition of load spectrum of helicopter tail rotor blades here computation fluid dynamic (CFD) numerical simulation are used. In this consideration for determination aerodynamic loads of helicopter tail rotor blades two computation models are used. In first model isolated tail rotor blade is considered. In the second computation model the complete helicopter is modeled including fuselage together with main and tail rotor blades. To verify fatigue strength of the tail rotor composite blade here is tested with respect to fatigue for one critical load case. In addition to experimental verification of tail rotor blade here is illustrated computation procedure for optimal design of the layered composite panel.