In order to prevent hazardous conditions of aircraft engine components throughout their entire in service life, structural integrity must be demonstrated in accordance to regularities set by e.g. EASA or FAA. Damage and fracture processes caused by cyclic loading play a significant role in this context. Furthermore, weight reduction and efficiency requirements are becoming increasingly challenging. In order to well understand the robustness of the component post its fatigue life, the evaluation of the crack propagation life must be analyzed with high precision. Many practical applications require assessments of multiple cracks varying in shape, initial size and location within large DoF domains. Therefore, at MTU Aero Engines a 1D approach has been developed based on analytical estimates for stress intensity factors. This tool is capable of assessing high numbers of crack scenarios within short computation times. However, certain applications require the reduction of assumptions applied within the 1D approach and also 3D effects such as stress redistribution need to be taken into account. Accordingly, a 3D FEM-based tool has been developed for the numerical prediction of cyclic fatigue crack propagation. By evaluating the stress intensity factor range at the crack tip of a preexisting crack, the growth increment is calculated and the crack shape is updated and re-meshed as the procedure restarts. Regarding load history the tool is capable of predicting the growth rate for constant amplitude loading as well as non-proportional various amplitude loading. In this contribution we briefly illustrate both modeling paradigms, review the numerical schemes and discuss underlying equations. We present examples and discuss the results of fatigue crack growth simulations. Through several cases we demonstrate the extend, to which a straightforward analytical 1D approach provides accurate results compared to the full blown 3D FEM-based scheme. We identify reasons for deviations and give recommendations for the best trade-off between accuracy and efficiency. Furthermore, it is highlighted how a combined integration of 3D and 1D approaches can be utilized most effectively for applications in aircraft engine development.