Sikorsky Aircraft has chosen Hamilton Sundstrand to supply the Utility Management System (UMS) for the CH-53K heavy lift helicopter, which is under development for use by the U.S. Marines. The UMS includes two different digital electronic computers, designed and developed by Hamilton Sundstrand. The computers manage air vehicle inputs for key CH-53K helicopter subsystems. Hamilton Sundstrand was previously selected to supply the CH-53K helicopter's secondary power systems, consisting of the environmental control system, auxiliary power unit, and main engine start system. The company also was chosen to develop the helicopter's fly-by-wire flight control system, which includes triple redundant computers, and main and tail rotor actuators.