Scope and Method of Study: This study focused on the development and use of the AT-SAT test battery and the Initial En Route Qualification training course for the selection, training, and evaluation of air traffic controller candidates. The Pearson product moment correlation coefficient was used to measure the linear relationship between the AT-SAT composite scores and the composite scores of the Initial En Route Qualification Training course. Multiple regression was used to determine the relationship between the Initial En Route Qualification Training course and the AT-SAT test battery sub-tests. Findings and Conclusions: The correlation coefficient between the AT-SAT test battery composite score and the Initial En Route Qualification training course was 0.216. There were twelve individual AT-SAT sub-tests with positive relationships to the Initial En Route Qualification training course. Eleven sub-test competencies were found to have a negative relationship to the Initial En Route Qualification training course and two competencies had no clear relationship. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]