Recent developments in constant frequency alternating current (ac) generating systems for aircraft have realised substantial increases in power-to-weight ratio and potential reduction in cost-of-ownership.

Essentially this has been achieved by employment of maximum synchronous generator speed, refinement and corresponding advantage of hydromechanical variable-ratio transmission technology and a more highly integrated configuration.

Each of these aspects has required an innovative philosophy and extensive testing to bring the technology to a point where such equipment can be confidently specified for the next generation of aircraft.