Ability of deutan color defectives to perform simulated air traffic control tasks

Air traffic controllers perform a variety of tasks which require them to identify, discriminate, and name colors. Qualification standards for this occupation require applicants and incumbents to have normal color vision. The validity of this standard has been questioned and is currently under review. In this study, 22 deutans and 78 normals were tested on a set of tasks which simulated critical tasks performed daily by air traffic controllers. The four tasks included discriminating red from black pencil marks on flight progress strips, color-naming of 1 degree and 0.1 degree discs, and identification of colored line segments embedded in a multicolored background. Deutans classified as mild were found to perform all tasks as well as normals. Moderate deutans performed only the large disc color-naming task as well as normals, whereas severe deutans performed none of the tasks as well as normals. Different methods for scoring the color vision tests were explored to determine their value as predictors of task performance. The D-15 relative error score was found to be the single best predictor of performance on the tasks (r-square = 0.602). It is concluded that mild deutan color defectives have adequate color vision for safe performance of several critical air traffic control tasks. Moderate and severe deutans do not. In addition, the results of several methods for scoring color vision tests can be used to predict group, but not individual, performance with high reliability.