Staggered threshold approach procedures combined with new tools show potential for achieving an increase in airport capacity of up to 10% - as well as reducing noise. A recent validation carried out by members of the Joint Undertaking (JU) are showing convincing results.
SESAR JU founding member, EUROCONTROL, together with SESAR members DSNA and Thales recently validated two new concepts to improve runway capacity and manage noise, based on Paris Charles de Gaulle Airport scenarios.
The first candidate solution, known as static pairwise separation for departures, tackled increasing departure traffic, with optimised wake turbulence separation minima, and improved separation delivery.
The second candidate solutions, known as dual threshold, involved landing aircraft on closely-spaced dependent parallel runways, using staggered thresholds to help reduce wake separation minima and increase throughput.
For a major European airport like Paris Charles de Gaulle, the new concepts, combined with the tools, can deliver significant benefits for departure and arrival peak periods and can make for a 10% increase of runway capacity. They also bring an added benefit of improved predictability.
The background
The validated concepts are part of two SESAR solutions PJ02-01 - Wake turbulence separation optimization and PJ02-02 – Enhanced arrival procedures, which focus on improving runway and airport throughput, taking weather, wake vortices, the environment and noise into consideration. They look at different traffic levels, future aircraft capabilities and different airport configurations.
These solutions belong to the SESAR 2020 project PJ02 – EARTH – Increased Runway and Airport Throughput that addresses capacity challenges at major airports.
The validated concepts
The two concepts focus on airports that manage departures and arrivals on closely spaced dependent parallel runways; they are aimed at optimising wake turbulence separation minima and separation delivery.
For arrival aircraft on parallel runways with staggered thresholds, a reduction of the wake separation minima can be achieved thanks to the height difference between the glideslopes.
Heavy and Super Heavy aircraft are assigned to the lower glideslope on the runway operated in mixed mode with departures. Medium and Light aircraft are assigned to the upper glideslope on the adjacent parallel runway with the staggered threshold, so avoiding the wakes generated by the Heavy/Super aircraft.
To manage the complex pairwise arrival separations, approach and tower controllers use a tool for optimised runway delivery (ORD), which displays separation indicators on final approach segments, so helping controllers to deliver safe, efficient reduced separation minima.
Expected benefits are twofold. Firstly, the aircraft noise footprint can be moved closer to the airport area for aircraft flying on the upper glide, reducing noise impact on the population in the approach area. Secondly, an increase in capacity throughput of up to 10% can be achieved as separation minima can be reduced for some aircraft pairs.
For departures, air traffic controllers use a dynamic departure indicator (DDI) tool to manage departures separations and applicable spacing constraints between outbound traffic in the Terminal Control Area (TMA).
The tool computes distance and time-spacing indicators and helps the tower controller to accurately and safely deliver the required time or distance spacing minima between departing aircraft.
The DDI tool is based on aircraft performance models of speed and climb profiles, calibrated on Radar and Mode-S tracks, and refined with machine-learning techniques.
Results of the departure validation show that in using the decision support tool, air traffic controllers were able to safely reduce the time between departures, increasing departure throughput, with no under-spacing events.
