this paper proposes a control scheme for permanent magnet machine (PMM) based aircraft starter/generator (S/G) operated in flux weakening (FW) mode. In contrast to previous publications, the proposed control scheme uses a single current regulator to adjust the q-axis reference voltage, and the d- axis voltage is calculated considering the maximum available voltage from the converter. This allows the full utilization of DC bus voltage and improves the machine efficiency. Furthermore, it is more robust against with regards to machine parameters variation. The analytical design results and the system performance are confirmed by time domain simulation and compared against traditional approach.