Measuring Biodynamic Feedthrough in Helicopters

Biodynamic feedthrough (BDFT) refers to a phenomenon where vehicle accelerations cause involuntary pilot limb motions which, when coupled to a control device, can result in unintentional control inputs. It is known that BDFT occurs in helicopters, amongst many other vehicles. The goal of the current study is to analyze the pilot's response to helicopter motion and experimentally determine the level of BDFT occurring in helicopters. In this study, BDFT was measured for the collective and the cyclic control devices, in roll, pitch, and vertical direction, for three different control tasks, a position task (PT) or 'stiff task', a force task (FT) or 'compliant task', and a relax task (RT). The study focuses on the influence of the pilot's neuromuscular dynamics on the level of BDFT. Two major conclusions can be drawn from the experimental results: 1) BDFT in helicopters is task dependent 2) the highest level of BDFT is measured in lateral direction, followed by longitudinal and finally vertical direction.