Global Engineering and Materials, Inc. (GEM) along with its team members, Clarkson University and LM Aero, propose to develop a mesh independent probabilistic residual life prediction tool for metallic airframe structures. The deterministic solver of this probabilistic analysis tool will be developed by integrating our cutting edge extended finite element toolkit for Abaqus (XFA) with a novel small time scale fatigue crack growth model for mesh independent fatigue crack growth prediction in a complex airframe structural component subjected to multiaxial and variable amplitude loading. The fast matching and narrow band technique will be implemented to track a curvilinear 3D crack growth without remeshing.