A method for determining a remaining useful life of an aircraft component, comprising: providing a usage and configuration information including diagnostic usage and configuration information provided from previous flights and sensor logs, detected fault logs, and/or real time data, such as shaft speeds, rotational speeds, axial loads, rotary loads, spall size, and/or spall distribution associated with the aircraft component; determining if a preexisting spall condition exists for the aircraft component based on the usage and configuration information; executing a spall initiation model for the aircraft component, the spall initiation model utilizing past usage loads, present usage loads, expected usage loads based on mission planning, physics based models and empirical methods to calculate spall and/or fault initiation and provide initial spall information including spall initiation period, an initial spall size, a spall upper bound, a spall lower bound, and/or spall distribution to a spall propagation model if the preexisting spall condition does not exist, wherein the spall initiation model provides a spall initiation life associated with the aircraft component by analyzing the usage and configuration information; after an actual component spall is detected or a component spall is modeled in the spall initiation model, executing the spall propagation model for the aircraft component, the spall prorogation model utilizing past usage loads, present usage loads, and/or expected usage loads based on mission planning, initial spall size, initial spall distribution, physics based models and empirical methods to calculate spall and/or fault propagation, wherein the spall propagation model provides a spall propagation life associated with the aircraft component by analyzing the usage and configuration information; and providing a remaining useful life by integrating the spall initiation life and the spall propagation life. providing a usage and configuration information including diagnostic usage and configuration information provided from previous flights and sensor logs, detected fault logs, and/or real time data, such as shaft speeds, rotational speeds, axial loads, rotary loads, spall size, and/or spall distribution associated with the aircraft component; determining if a preexisting spall condition exists for the aircraft component based on the usage and configuration information; executing a spall initiation model for the aircraft component, the spall initiation model utilizing past usage loads, present usage loads, expected usage loads based on mission planning, physics based models and empirical methods to calculate spall and/or fault initiation and provide initial spall information including spall initiation period, an initial spall size, a spall upper bound, a spall lower bound, and/or spall distribution to a spall propagation model if the preexisting spall condition does not exist, wherein the spall initiation model provides a spall initiation life associated with the aircraft component by analyzing the usage and configuration information; after an actual component spall is detected or a component spall is modeled in the spall initiation model, executing the spall propagation model for the aircraft component, the spall prorogation model utilizing past usage loads, present usage loads, and/or expected usage loads based on mission planning, initial spall size, initial spall distribution, physics based models and empirical methods to calculate spall and/or fault propagation, wherein the spall propagation model provides a spall propagation life associated with the aircraft component by analyzing the usage and configuration information; and providing a remaining useful life by integrating the spall initiation life and the spall propagation life. <EOS>