Vertical-Plane Pendulum Absorbers for Minimizing Helicopter Vibratory Loads

This paper discusses the use of pendulum dynamic absorbers mounted on the blade root and operating in the vertical plane to minimize helicopter vibratory loads. The paper describes qualitatively the concept of the dynamic absorbers and presents results of analytical studies showing the degree of reduction in vibratory loads attainable. Operational experience of vertical plane dynamic absorbers on the OH-6A helicopter is also discussed.