This paper investigates the effects of different automation design philosophies for a helicopter navigation task. A baseline navigation display is compared with two more advanced systems: an advisory display, which provides a discrete trajectory suggestion; and a constraint-based display, which provides information about the set of possible trajectory solutions. The results of a human-in-the-loop experiment with eight pilot participants show a significant negative impact of the advisory display on pilot trajectory decision-making: out of the 16 encountered off-nominal situations across the experiment, only 6 were solved optimally. The baseline and constraint-based display both lead to better decisions, with 14 out of 16 being optimal. However, pilots still preferred the advisory display, in particular in off-nominal situations. These results highlight that even when a support system is preferred by pilots, it can have strong inadvertent negative effects on their decision-making.

This paper investigates the effect of employing different display design principles for human–machine interaction in helicopters. Two obstacle avoidance support displays are evaluated during low-altitude forward flight. A baseline head-up display is complemented either by a conventional advisory display or a constraint-based display inspired by ecological interface design. The latter design philosophy has only been sparsely applied in the helicopter domain. Twelve helicopter pilots participated in an experiment in a research flight simulator. We found no significant effects of the displays on objective performance measures. However, there was a trend of decreasing pilot workload and increasing situation awareness when employing the support displays, as compared to the baseline display. The constraint-based display had the largest positive effect and increased the resilience of the pilot–vehicle system toward unexpected events when considering the safety of the flown trajectories. Pilots preferred the advisory display in nominal situations and the constraint-based display in off-nominal situations, reproducing similar findings from research in the fixed-wing domain. This experiment showed the potential of the developed constraint-based display to improve subjective pilot ratings, pilot preference, and safety during unexpected events. Future research will investigate more complex scenarios with longer time frames, possibly eliciting more divergent effects of different display design principles.

Head-down hover displays and instrument panels theoretically provide all necessary 2ight data information to control low-speed helicopter manoeuvring. However, past experiments have shown that head-down displays can incur high workload, control instability, and even loss of control when used as the sole 2ight data source. This paper investigates the reasons for this instability incurred by replacing good outside visuals with a head-down hover display and an instrument panel. A pilot model based on crossover theory is developed for a linear six-degree-of-freedom Bo. helicopter model. Utilising a target trajectory based on-theory and assuming perfect information availability, the developed model can perform the required manoeuvring task with a control time-delay stability margin of . s (with SAS) or . s (without SAS). Then, the actual information availability based on human perception methods and limitations is discussed. A pilot-in-the-loop experiment in the SIMONA Research Simulator qualitatively validates the developed pilot model for good outside visuals. However, the pilot model does not capture the added diZculties of having to utilise the hover display and instrument panel instead of good outside visuals; during the experiment, the task was impossible to complete with only these displays. This is likely caused by an increase in control time-delay, which in turn is caused by the loss of peripheral and flow 1eld information, a more abstract information representation compared to good outside visuals, and the fact that the pilot now needs to scan multiple displays to acquire all necessary 2ight state information. Improving head-down hover display symbology and scaling factors might rectify some, but probably not all of these effects.