Impact of automation level on airline pilots' flying performance and visual scanning strategies: A full flight simulator study.

Cockpit automation has brought significant benefits in terms of mental workload and fatigue. However, the way primary flight instruments are monitored by pilots may be negatively affected by the high confidence in systems. We examined the effects of automation level on mental workload, manual flight performance and visual strategies. Twenty professional pilots performed six landing scenarios at three levels of automation depending on flight director (flight path guidance) and autothrust (automatic management of the speed) engagements. Higher levels of automation increased flight performance and reduced mental workload, but were associated with a decrease in vigilance to primary instruments, particularly flight path indicators and engines' thrust. We also found that gaze entropy was sensitive to pilot role (pilot flying vs pilot monitoring) and automation level. These results confirmed the risks of adverse effects of automation on visual monitoring. Designing procedures for pilots to actively monitor automated cockpit systems should be encouraged.