Evaluating Third-Sector Apron Operations: Radio Occupancy and Interface Tasks

Opening a third apron-control sector adds a command and support pair, yet a lower average radio occupancy may conceal busy hours during its operation. We evaluated 30 completed openings at Beijing Daxing International Airport using channel records, exact configuration times and two-sector references. The 114 clock-hour records covered 112.36 h of operation and 224.71 additional position-hours. Extending the reference pool from 1008 to 1454 airport hours provided traffic-composition-matched comparisons for every opening hour. Eight summer Plan 1 hours exceeded the local 70% reference, all on the third responsibility area’s channel. In two lower-average openings, the respective busy-hour contrasts were +7.64 and +4.98 percentage points. Neither hour had a reference with identical recorded context in the full candidate pool; six other busy hours retained positive contrasts. Plan 1’s busiest-channel share was lower in all 21 openings, while total radio use was higher in 13. Expanded summer mean differences were −5.54 and +1.45 percentage points for Plans 1 and 2, with both conditional intervals spanning zero. Interface-task rates and actual staffing coverage described the activity accompanying the added pair. The findings support evaluating the complete opening through its hourly radio profile, the available comparisons for busy hours and the associated interface activity.