Spacing and Pressure to Characterise Arrival Sequencing

This paper presents an analysis of the sequencing of arrival flights at four European airports representative of different types of operation with more than 14000 aircraft pairs. The motivation is to better understand and characterise how sequencing is performed in dense and complex environments during peak periods. The analysis, purely data driven, focuses on the evolution of flight additional time, spacing deviation and sequence pressure. The main results are: (1) at 15 minutes from final, the average flight additional time varies from 4 to 6 minutes (depending on the terrain), with a variability between ±2.5 and ±4 minutes; (2) at 15 minutes from final, the spacing deviation varies from ±3min to ±4min, and converges toward zero at 2min to final; (3) the sequence pressure (number of flights sharing the same arrival slot if no sequencing) is low at terminal area entry, and then peaks at some distance/time from final before decreasing toward a target pressure of one flight per slot, closer to final. The pressure levels and their peak distribution over the terminal area differ notably among destinations, highlighting the effect of the sequencing technique. Future work will involve analyzing high-pressure situations, in view of identifying the appropriate pressure characteristics, i.e. trade-off between the required minimum pressure and acceptable controller workload.