Cockpit Displays of Traffic Information and Pilot Bias in Time-to-Contact Judgments

Pankok C Jr, Kaber DB. Cockpit displays of traffic information and pilot bias in time-to-contact judgments. Aviat Space Environ Med 2014; 85:597–604.

Introduction: Pilots are susceptible to over-reliance on distance when making relative time-to-contact (TTC) judgments of surrounding intruders, referred to as “the distance bias.” We tested the effect of adding perceptual cues and an information feature to cockpit displays of traffic information to mitigate this bias. Method: There were 14 general aviation pilots who participated in a simulated flight scenario and were asked to make relative TTC judgments. Three levels of perceptual cue (blinking, color-change, and no-cue) were crossed with two levels of velocity data tag (present and absent) with identification of the highest risk intruder as a response. Results: Perceptual cues were associated with more accurate high-risk intruder selection (color = 95.95% correct, blinking = 95.98%, no-cue = 87.89%), decreased response time (color = 3.68 s, blinking = 3.19 s, no-cue = 6.08 s), reduced visual attention demand (color = 57% of attention, blinking = 58%, no-cue = 62%), lower workload ratings (color = 28.38/100, blinking = 29.66/100, no-cue = 48.91/100), and higher performance confidence ratings (color = 83.92/100, blinking = 82.71/100, no-cue = 58.85/100) than the no-cue displays. There was no difference between blinking and color cue displays. The data tag was associated with lower response times (present = 4.13 s, absent = 4.50 s) and higher confidence ratings (present = 78.69/100, absent = 71.63/100) than displays without. Displays including the blinking cue, color-change cue, and data tag were preferred over displays that did not include these features (color = 8 pilots, blinking = 6, no-cue = 0). Discussion: The added display features were effective in mitigating the effect of the distance bias on pilot performance measures and received favorable subjective ratings.