Evaluation of Mechanical Servo-Actuator for Flight Control Systems

The report discusses the design, fabrication and test of an all- mechanical servo-actuator with manual override capability for helicopter flight control application. The all-mechanical system is a power boost with a mechanical override feature and provides mechanical amplification of signal torques from 0.5 to 1.0 lb-in. to operate output torque loads up to 1,142 lb-in. The goal of the program was to develop a mechanical servo-actuator to operate the helicopter swashplate, for cyclic and collective pitch control, with performance characteristics comparable to those of the hydraulic servo-actuator on the XH-51A helicopter. The test item was subjected to a series of tests, including force threshold, resolution, frequency response, step response, and endurance.