Subjective And Objective Workload Assessment Of Novel Autorotation Cueing Methods Using Haptic Cues

Abstract

The helicopter autorotation manoeuvre is an emergency flight manoeuvre used primarily to safely land in the event of a main rotor engine failure. Executing this manoeuvre is challenging because pilots must perform multiple tasks simultaneously, each with precise timing. Accidents, some fatal, continue to occur when carrying out an autorotation manoeuvre and these are generally attributed to pilot error. There is therefore a recognised need to develop a system to aid pilots to perform a safe, survivable autorotation. As part of a wider project to develop novel autorotation cueing methods by the authors, several piloted simulated trials had been conducted using the University of Liverpool's HELIFLIGHT-R full motion simulator. This paper reports on an investigation into the potential correlation between subjective workload metrics collected during those trials and objective measures which look promising as a surrogate for workload. Subjective workload was collected using the Bedford Workload Rating Scale. The objective assessment used was the weighted combined multi-axis attack activity rate developed at the University of Liverpool. Three different initial start conditions for the autorotation manoeuvre with and without haptic cueing in a good visual environment condition were tested. It was hypoth- esised that the subjective workload ratings would be well correlated with one or both of the average or peak multi-axis attack activity rates for the phase of the manoeuvre under consideration. However, no correlation was found between either the combined multi-axis localised average or peak attack activity and the subjective workload reported by the test pilots.