In competitive ski-jumping, not only the athletes’ motoric abilities are important. Their body weight plays a major role in achieving appropriate jump lengths. This has lead to alarmingly underweight athletes with high risk in health, and several cases of anorexia have been reported. Questions of safety, health and fairness are often closely associated with competition regularities. As a main goal, the development of future regulations focusing on health and safety of the athletes seems urgently necessary. Important biomechanical factors are investigated by the cooperation partner. At the institute, the aim of the project is to achieve a better understanding of aerodynamical fundamentals. Detailed knowledge of lift and drag production as well as their interaction during different flight phases is acquired. Therefore, we compose a jumper model from geometrically simple objects, like rectangular bodies, cylinders, cones etc. Starting from a simple model of the upper part of the body, legs, arms, head and skis are added modularly for separate and combined wind-tunnel measurements. From this, the individual influence of all parts on aerodynamic forces and their interaction may be deduced. Furthermore, numerical simulations applying various turbulence models are performed with a commercial CFD code (Computational Fluid Dynamics) for comparison. This should yield conclusions on the reliability of CFD simulations in sports.