Abstract Collective bounce is a rotorcraft–pilot coupling phenomenon caused by vertical vibrations in the aircraft cockpit that are transmitted to the collective lever through the torso, the left arm and the hand of the pilot, and fed back to the rotor through the collective pitch control. This paper shows that collective bounce is rooted in the coupling of the pilot biodynamics with the rotor coning mode. The damping of the coning mode, usually large, introduces significant phase delay in the response to collective pitch. When coupled in feedback with the pilot biodynamics, such delay may lead to marginal stability conditions or even to instability. The basic mechanism of this coupling is shown using simple analytical models, and confirmed using detailed helicopter models. The influence of several design parameters is investigated, and possible means of prevention are briefly discussed.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    The role of rotor coning in helicopter proneness to collective bounce


    Contributors:

    Published in:

    Publication date :

    2014-04-12


    Size :

    11 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English





    Rotor hub with enforced collective coning

    CHOI JOUYOUNG JASON / STAMPS FRANK B | European Patent Office | 2020

    Free access

    ROTOR HUB WITH ENFORCED COLLECTIVE CONING

    CHOI JOUYOUNG JASON / STAMPS FRANK B | European Patent Office | 2019

    Free access

    Updating and Optimization of a Coning Rotor Concept

    Crawford, Curran / Platts, Jim | AIAA | 2006