The simulation industry's conventional solution to the problem of providing flight control feel forces in a training device is based on hydraulic loading systems. The current state of the art in such control loading systems consists of a hydrostatic actuator controlled by a closed loop digital system. While the performance of these systems meets all training requirements, the cost of such systems remains high. Today's highly competitive simulation marketplace demands reduced costs. Considering current digital control loading systems, the hydraulic components (hydrostatic actuators, hydraulic plumbing, pumps, and valves) are a major recurring cost. Replacing these hydraulic components with an alternative active loading system has the possibility of significantly lowering recurring costs. In addition there has been an increasing trend in the industry to non-motion based specialty trainers, in which case a non-hydraulic solution is an advantage.

An electric motor based approach to the control loading problem is presented in this paper. Several systems using this approach have been developed to date, but have not exhibited the performance and fidelity to warrant consideration in most high fidelity training devices. The paper discusses an electric control loading system with performance that rivals current hydraulic systems. Particular emphasis is placed on the design considerations, the mechanics of the loader design, the electronics required, and the software algorithms developed. System performance is appraised against FAA PHASE II standards. The cost advantages and the applicability to various training devices is also examined.