This study, conducted within the framework of the AMBER project of Clean Aviation in collaboration with Avio Aero, analyzes the dynamic behavior of a hybrid-electric propulsion system, focusing on the torsional response during transient switching between propulsion modes. The system is modeled as a kinematic chain consisting of shafts, disks, and nonlinear connecting elements, with particular attention to the sprag overrunning clutch. Numerical models of increasing complexity have been developed to describe the system’s behavior. Simulations have been carried out to study the system's response in different operating conditions, helping to understand the role of the clutch in the overall dynamic behavior.