Conflict Perception by ATCS Admits Doubt but not Inconsistency

Though there is considerable agreement among the past studies about the great variability in conflict judgments by Air Traffic Control Specialists (ATCS), this work puts a first step forward in direction of a common core shared by controllers for perceiving conflicts. First, traffic scenarios were built from real traffic recordings, showing two converging aircraft. Three variables characterized these scenarios, respectively quantifying horizontal and vertical separations and the time when the judgment had to be formulated. The conditions created by factorial manipulation of three variables led to the design of short scenarios (about 1 min) upon which 161 controllers gave their opinion about the possible occurrence of separation loss (less than 3 NM and 1000 feet). The data, currently being analyzed, already show an important variability among experts, confirming the results of the past studies. But the way that the median values of responses are spread over the combinatory range of the scenarios appears very coherent and could prefigure a model of conflict perception by ATCS community. Further, values guaranteeing a certain level of security have been found and compared both on the horizontal plane and altitude. It shows (and quantifies) the higher efficiency, or reliability of those obtained on the plane. Considering anticipation in the judgment (variable D°A), it shows how uncertainty varies while anticipation decreases. Moreover, particular variations of uncertainty appear within responses resulting from scenarios with “near minima” separation values. These variations tend to evidence the line of thought of ATCSs dealing with the limits of the margin they have to set for a conflict/non-conflict classification.