In this video, the decommissioned rotor is turned out of the wind in the so-called "L-position" for maintenance work, whereby large flow separations take place behind the cross-flow, angular nacelle. The nominal wind speed and the maximum wind speed designed for the turbine are simulated to investigate a normal and an extreme case. These cases were simulated with the DES method and the Lambda-2 isosurfaces of the vortex structures are shown here. Pilot studies with these flow fields will be carried out at the project partners with a helicopter flight simulator to determine the effects on helicopter flight dynamics".