Attention allocation in Tunnel-in-the-Sky on HUD and HDD for visual flight

A series of flight simulations was carried out to investigate the causal factors of attention capture, focusing on a traffic detection task while following a curved trajectory using a Tunnel-in-the-Sky display. Display location (head-up or head-down) and gain were selected as display parameters, and traffic detection time and path tracking performance were measured. The results showed that the HUD gave the best path tracking at the expense of traffic detection performance. The same tendency when using a magnified HDD supports the hypothesis that using a high display gain with a Tunnel-in-the-Sky displays directs much attention to the control task. The present experiment could not identify any differences that might be caused by scanning load due to the location of the display. Also, no tendency of attention capture was observed when the Tunnel-in-the-Sky display was presented on a HDD in comparison with conventional visual (compound) flight.