Benefits of precision scheduling and spacing for arrival operations

Advances in arrival scheduling and controller aids for spacing have potential benefits of reducing aircraft delays and increasing airport arrival throughput. Schedulers use fixed arrival paths to estimate aircraft time-to-fly and assign them arrival slots based on the required separation plus 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 mid-term traffic demand scenarios and technologies using spacing buffers as low as 0.3 nmi. The analysis published here characterizes the observed arrival spacing behavior of 29 runways belonging to 15 airports within 8 of the busiest terminal areas across the United States for 32-60 days worth of traffic. The typical observed instrument arrival buffers ranging from 0.5 to 1.5 nmi would equate to roughly 10-20% increase in runway arrival capacity if buffers were reduced to 0.3 nmi. The effect of fixed arrival routing on terminal area flight time was also studied. Most runways studied had significant path stretch delay. This work estimates that 1-2 min of this delay could be reduced with precision scheduling and most of the remainder could be absorbed by speed control.