The Research focus on the Structural Integrity of Ageing Airplanes especially Pilatus P3, Hunter, Venom, Vampire, and Junkers Ju-52. The golas is to perform an Assessment of Critical Locations for Fatigue Damages. These Locations will be analyzed using AFGROW Crack Growth Analysis Tool together with Structural Analysis. Special Stress Gradient were developped to run the Geomteric Fracture Model according to the Structural Details. The Goal ist to release SSID for all Swiss Operators in Collaboration with FOCA.