The survey-type study of several hundred journeymen radar control specialists of four Air Route Traffic Control Centers was conducted in order to determine the extent to which job performance might be associative with chronological age and length of experience in control work. For each of several experimentally derived ratings of job performance, a statistically significant and negative relationship was found with age. Mean group ratings for controllers over 40 years of age were significantly lower than those of younger groups. Length of experience, when considered independently of age, was found to be of negligible importance and no statistically significant interaction effects of age and experience were discovered. However, a comparison of the data for dichotomized groups of controllers aged '40 and less' and '41 and older' revealed a higher mean rating for the younger group of controllers at every experience level. Yet these differences between the younger and older ATCSs of each experience group were nonsignificant. (Author).