Flight Demonstration of an Active Helicopter Seat System for Aircrew Whole Body Vibration Mitigation

Abstract

Helicopter aircrew are exposed to high levels of Whole-Body Vibration (WBV) in fight operations, which may degrade their ride comfort and performance in the short-term, and contribute to adverse health issues in the long-term. The Active Seat Mount technology, presented in this paper, was developed to reduce the whole-body vibration of the helicopter aircrew through active cancellation of the N/rev vibration peaks related to the helicopter main rotor speed. The latest development of the Active Seat Mount technology including structural redesign for integration into the helicopter rear cabin, extensive tests of human occupants on the shaker table and flight tests on the NRC Bell-412 helicopter are described in detail. The shaker and flight test results demonstrated that the redesigned Active Seat Mount achieved significant reduction of the occupant WBV levels at the bottom seat cushion interface per ISO2631-1 metrics and also reduced the occupant head vibrations simultaneously. The promising results show that the Active Seat Mount is capable of improving the ride quality of the Bell-412 helicopter in representative flight conditions and mitigating adverse long-term health issues of the helicopter pilots.