Abstract: The present invention provides an improved DC electric starter-generator having high starting torque, compact size and weight, increased efficiency and reliability, and being particularly suitable for a starter-generator for aircraft engines but also suitable for other applications. The DC electric starter-generator has a rotor assembly including a rotor core having a cross-sectional silhouette formed by a hub having preferably one of four and six appendages extending radially from the hub. Each appendage includes a flanged formation having an outer edge which is formed to obtain a desired commutation current wave form. The DC electric starter-generator further includes a stator assembly with a plurality of stator slots, each of which include at least two phase windings which are wound in a direction opposite each other to substantially reduce the effects of counter e.m.f. during operation.