Coupled Arrivals and Departures Creating the Most Efficient Runway Utilization

High demand, capacity constrained airports typically strive to optimize the usage of their runway resources. The capacity of a given runway depends on the arrival-departure ratio, where the maximum throughput is normally achieved in mixed-mode operations – when planes land and take off on the same runway at the same time. The optimum ratio depends on demand predictions and optimization targets. Single runway airports, in particular, face the challenge to find the best mix of arrival and departing traffic given the various constraints and inherent uncertainties of the respective operations.

In January 2008, the United Kingdom’s National Air Traffic Services (NATS) put Harris’ Orthogon Arrival Manager (AMAN) into operation at London’s Heathrow and Gatwick Airports to optimize the arrival sequences based on Target Landing Time calculations. Additionally, in May 2014, the Orthogon Departure Manager (DMAN) was launched at Gatwick Airport. Utilizing Airport Collaborative Decision Making (A-CDM), where all airport partners share information and follow a common plan, DMAN optimizes Target Take-Off Times (TTOT) and Target Start-Up Approval Times (TSAT) by linking arrivals to turnarounds to departures.

While both individual systems offer important benefits, coupling AMAN and DMAN systems unlocks additional, invaluable improvements for mixed-mode operations at a single runway airport like Gatwick. The International Civil Aviation Organization (ICAO) Aviation System Block Upgrades (ASBU) document describes the advantages achievable through a coupled AMAN/DMAN system.

Predictability is improved through a decrease in uncertainty in airport and terminal demands. Moreover, efficiency gains are possible as a result of harmonizing, streamlining and de-conflicting the respective traffic flows. The synchronization of arrival and departure traffic allows Air Navigation Service Providers (ANSPs) to maximize their airspace. Also, dynamic scheduling and dynamic runway configuration is supported, allowing for easier accommodation of arrival/departure patterns.

In the framework of Single European Sky ATM Research (SESAR), the Orthogon AMAN and DMAN system at Gatwick Airport was extended and used in a simulation for the coupled AMAN/DMAN validation exercises (SESAR work package 6.8.4) representing Approach and Tower operations.

"Getting the most from a single runway needs great cooperation between tower and approach." John Greenwood – SESAR 6.8.4 Team Lead and Research Analyst at NATS.

During the simulation, the Orthogon system was extended to support the runway policy known as “packing and gapping” – the size and frequency of gaps between arrivals to allow for departures. Coupling AMAN and DMAN allowed for an optimized mixed-mode runway sequence pattern, coordinated between Approach and Tower supervisors, to be directly entered into the system. Research results showed, that by coupling AMAN and DMAN, airports are able to manage arrival and departure queue’s more safely and efficiently while reducing flight delays, airport costs and fuel consumption, improving air traffic control and airport operations.

The simulation was conducted in the NATS Corporate and Technology Centre using ACE simulation software, and ran from September 22, 2014 until successfully finishing on October 11, 2014 with an uncoupled mode serving as baseline.