Impact of ADS-B on Controller Workload: Results from Alaska's Capstone Program

The Capstone program introduced avionics in Alaska that included ADS-B equipment, starting in the year 2000. The program succeeded in equipping 208 aircraft in the Yukon-Kuskokwim Delta by the end of 2004, resulting in Capstone-equipped aircraft accounting for nearly 100% of part-135 operations by airplanes based in that region. This paper estimates the impact of the use of Capstone equipment on controller workload. It summarizes the results of a controller survey regarding the effect of Capstone equipment on controller tasks, and provides quantitative results regarding the effect of ADS-B equipment on controller workload. From the survey 57% of controllers indicated that they needed less time providing IFR separation services than without ADS-B, and 79% of the controllers felt that the overall efficiency of their operation had increased with ADS-B. An analysis of flight progress strips showed that the currently deployed Capstone equipment, when operating properly as required by ATC, would provide an 18% reduction in controller communications workload. The analysis also indicated that if all the aircraft in the Y-K Delta were properly equipped, the reduction in communications workload would be 26%