The Evaluation of a Stall-Flutter Spring-Damper Pushrod in the Rotating Control System of a CH-54B Helicopter.

摘要

The report describes a program conducted to evaluate the effect of rotating control system damping on stall-induced control loads and on aircraft handling qualities in stall. Such damping was introduced in the CH-54B control system by replacing the standard pushrods by a spring-damper assembly. The CH-54B helicopter was chosen as the test vehicle because it exhibits stall-induced loads. Dynamic analyses defined pushrod stiffness and damping characteristics required to reduce the high-frequency torsional response of the main rotor blades. Spring-damper pushrods exhibiting the desired characteristics were designed,fabricated,and laboratory tested to assure that design requirements were met. The spring-damper pushrods were installed on a test rotor head and tested on the Sikorsky main rotor whirl tower. (Modified author abstract)