The aim of this project is to design, manufacture, commissioning and validate of one complete driving system for a ground test bench intended to be used for aircraft starters/generators testing. The proposed system is complete and include one DC motor (120 kW) with associated power electronics, Human Machine Interface, Control System, Supporting Frame, High-speed Couplings, High-speed Transmission, Cooling circuit, Complete measurement System and Associtaed Software. In order to achieve a unitary test bench with low maintenance costs, we will implement innovative solutions based on the latest technologies in the fields of mechanical and electrical drives, mechanical transmissions, measurements and data processing. The proposed test bench will be able to testing EUTs (generator and/or starter/generator) in conditions similar to their use on aircraft. It will assure minimum energy consumption through energy recovery and its reintroduction in the process. The system will be environmental friendly, will use a reduced amount of oil and will have optimal mechanical regimes during service operation. Innovative aspects of the proposal are: mechanical transmission with high efficiency by using recess gear system and polygonal shafts; bidirectional and birotational speed multiplier with one output able to provide testing of EUT, both as a starter and generator, continuously and in conditions similar to their use on aircraft; use smart regenerative converters with high performance and high energy efficiency; non-contacting measuring of torques and speeds; use of specialized software for complete system configuration and management. The characteristics required by the Call for Proposal will be satisfied by those listed above.