Methodology to Analyse Handling Qualities Under Force Gradient Transitions of an Active Sidestick

Abstract

In recent years, active sidesticks have been used in concepts of civil aircraft enabling more intuitive force-feedback, amongst other improvements. But mode degradations or mechanical failures can cause sudden transitions in the force–deflection gradient. During manual control, such an event can lead to overcontrol by the pilot and into pilot-in-the-loop oscillations. A methodology is developed to investigate the impact of these events on pilot–vehicle system dynamics. Tracking tasks are designed to repeatedly elicit pilot reactions comparable to those of sudden and unexpected transitions. First simulator tests proved the methodology to be effective in surprising the pilot and preventing memorisation of the task. The tests reveal that transitions have a greater impact when pilots are well adapted and force gradients decrease.