A method and method of estimating fatigue life of a structure is disclosed. In one embodiment, the method may include determining strain on the structure using a plurality of gauges positioned on the structure. The method may also include detecting a parameter of the structure with a plurality of sensors positioned on the structure. Further, the method includes converting the detected parameter and the determined strain to proportional loads acting on the structure and transforming the proportional loads to coordinate system data associated with the structure. Based on the coordinate system data, the fatigue life of the structure may be estimated.