In the Aerospace field, the phenomenon of fatigue is one of the biggest challenges which have to be considered during the design phase. Material flaws, pre-cracks and crack initiations due to cyclic loading may lead to crack propagation in aircraft components. For aero-engine parts, because of high temperatures and time-dependent loads, this occurrence induces often a catastrophic failure. During the product development, a Damage Tolerant Design must be made, within an accurate prediction of the phenomenon. Because of the intricate geometries and loadings, the result is frequently a mixed-mode crack propagation and advanced tools for its estimation are required. Cracktracer3D is an MTU software able to study the mixed-mode cyclic crack propagation, based on the calculation of the Stress Intensity Factor from the FEM stress field analysis.