Levels of helicopter control force inputs during in-flight emergency conditions as a function of aviator experience

Abstract

In response to the dearth of information available regarding the magnitude of force inputs required to operate helicopter controls under emergency conditions, 12 male U.S. Army aviators each flew six normal and six simulated emergency (‘hydraulics-off’) approaches and landings in an army utility helicopter. Cyclic, collective and pedal outputs recorded during the last 60 s of flight prior to each touchdown revealed significant differences in the magnitude of the forces applied as a function of hydraulics condition and time to touchdown: i.e.. forces differentially increased as touchdown neared during hydraulics-off approaches. Significant interactions involving level of experience were encountered; the nature of the effects differed among the various controls and directions of input The descriptive statistics shows the overall mean and median forces for both groups of aviators to be below the helicopter control-referenced maximal 4 s strength capabilities of small Army males and females for all inputs except those in the downward direction on the collective.