Permanent magnet synchronous motors are very suitable in applications demanding high power density with high performance requirements, such as in aerospace actuators. Achieving high performance targets while keeping the total weight of the electrical machine to minimum values is quite challenging and requires an ideal machine design with a comprehensive understanding of power losses. As a result, this paper focuses on a detailed investigation of losses and machine performance, taking into account different operating conditions. Furthermore, 3D FE models were used in this work to accurately predict eddy current losses in the rotor components. Finally, the experimental findings obtained from the prototype are provided to highlight the efficiency of the developed numerical models and to verify the machine design. The analysis results are in good agreement with the experimental results with a maximum 3.2% error in terms of efficiency.