Automated Spacing Support Tools for Interval Management Operations during Continuous Descent Approaches

In this study, pilots were asked to achieve a specific time in trail while flying an arrival into Louisville International airport. Weather shortly before the start of the descent added variability to the initial intervals. A spacing tool calculated airspeeds intended to achieve the desired time in trail at the final approach fix. Pilots were exposed to four experimental conditions which varied how strictly the pilots were told to follow these speeds and whether speeds had to be entered into the autopilot manually. Giving the pilots more discretion had little effect on the final spacing interval. However, pilots required to enter speeds into the autopilot manually did not effectively manage their airplane’s energy resulting in less accurate performance. While these results may not always generalize to alternative spacing implementations, one should not assume pilots manually closing the loop on automated commands can perform as well as a fully automated system.