Time-To-Contact Perception During Simulated Night Landing

In 2 experiments, nonpilots made time-to-contact (TTC) judgments during simulated oblique descents toward a groundplane. Experiment 1 revealed a significant effect of simulated glideslope on TTC judgments: 3-degree simulations were underestimated, 6-degree simulations were generally accurate, and 9-degree simulations were overestimated. However, there was a significant reduction in this glideslope effect when the simulated aimpoint was explicitly (as opposed to implicitly) identified throughout the display. This glideslope effect was also found to disappear in Experiment 2, when aimpoint distance was held constant for all glideslopes, suggesting that TTC was being indirectly calculated based on perceived distance.