Offshore-Helicopter-Operations are frequently conducted in both turbulent and degraded visual environ-ments (DVE). This investigation assesses the combined influence of turbulence and DVEs on pilot workload to identify first limits for safe operations. Flight tests using a simulation model of the research helicopter ACT/FHS (Active Control Technology/Flying Helicopter Simulator) flight mechanics model were conducted in the Air Vehicle Simulator (AVES) at DLR Braunschweig. Tests were completed using four pilots, and results show the effects on pilot workload, task performance and control input activity. It was found that DVE and turbulence increase the workload and reduce task performance, but each in a different manner. Fur-thermore, the impact on control activity and pilot induced oscillation tendencies are shown to have depend-ency upon the environmental conditions.