Benefits of Precision Scheduling and Spacing for Arrival Operations

Abstract

Advances in arrival scheduling and controller aids for spacing have the potential benefits of reducing aircraft delays and increasing airport arrival throughput. Schedulers use fixed arrival paths to estimate aircraft’s time-to-fly and assign them arrival slots based on the required separation with a buffer. Concepts that reduce arrival time uncertainty can take advantage of advanced scheduling with smaller spacing buffers. These concepts have been successfully demonstrated with a handful of near- to midterm traffic demand scenarios and technologies using spacing buffers as low as 0.3 n mile. The analysis published here characterizes the observed arrival spacing behavior of 29 runways at 15 airports in eight of the busiest terminal areas across the United States during 32–60 days worth of traffic. The typical observed instrument arrival buffers ranging from 0.5 to 1.5 n mile would equate to roughly a 10–20% increase in runway arrival capacity if buffers were reduced to 0.3 n mile. The effect of fixed arrival routing on terminal area flight time was also studied. Most runways studied had a significant path stretch delay. This work estimates that 1–2 min of this delay could be reduced with precision scheduling, and most of the remaining delay could be absorbed by speed control.