In this paper, a comparative optimal design of Permanent Magnet Motors (PMMs) for aerospace actuation applications based on single and double layer Fractional Slot Concentrated Winding (FSCW) topologies with different motor segmentation strategies is undertaken, by means of a combined electromagnetic, fault tolerance and thermal evaluation. Initially, analytical machine equations and 2D Finite Element (FE) analysis are employed for the determination of the motors basic dimensional and operating characteristics. Both configurations considered are in a next step optimized regarding the mean torque, efficiency, torque ripple, induced Electromotive Force (EMF) quality and motor weight. The proposed methodology involves appropriate handling of mean torque and induced EMF as constraints through the application of a particular single-objective Particle Swarm Optimization (PSO) technique accounting also for multiple motor operating conditions. Fault tolerance and thermal robustness of the optimized motors are also examined. Both single layer and double layer FSCW PMM optimal configurations present complementary advantages for this class of applications.