The transportation sector, accounting for about one fifth of all greenhouse gas emissions, is facing a significant transformation in order to become more climate-friendly. In terms of air transportation, there are several important steps on the way to making flying sustainable both for the planet itself and for people directly or indirectly being exposed to its effects. In the state of the current air traffic operations, where environmentally friendly propulsion systems and fuels are not yet implemented on a large scale, enhancing the efficiency in the airspace can help to bring us closer to the environmental goals of aviation. Such solutions may include improved synchronization of arriving flights in the Terminal Maneuvering Area (TMA), in which congestion is a problem for many airports.  

In this thesis, we first explore and develop methodologies for assessing the environmental impact of the operations in TMA. More specifically, the goal of the assessments is to quantify the additional fuel consumption, gaseous emissions and noise that comes from horizontally and vertically inefficient arrival operations in TMA. We perform our assessments on a couple of European airports, including Stockholm-Arlanda.   

Secondly, we propose a Mixed Integer Programming (MIP)-based optimization model which provides for conflict-free arrival operations, where aircraft fly fuel-efficient Continuous Descent Operations (CDOs), applied to Point Merge (PM) arrival procedures, with the primary purpose to serve as a route assigner. We base our optimization on real scenarios, from actual transmitted flight data, and model realistic descent profiles considering the operational capabilities of the specific aircraft type. Additionally, the optimization model ensures the required spacing between aircraft taking off and landing in case the runway is used in a mixed mode. We evaluate our solutions by assessing numerous performance metrics, including environmental efficiency, and compare to the actual trajectories of the real operations. On two European airports implementing PM procedures, we demonstrate that our optimization model provides improved vertical performance as well as reduced time and distance flown in TMA, contributing to reduced levels of noise and fuel savings, accompanied by decreased emissions. 

As air traffic volumes continue to grow, understanding and managing traffic flows within Terminal Maneuvering Areas (TMAs) has become essential to meet increasing capacity demands. TMAs, the airspaces surrounding airports managed by Air Traffic Controller (ATC) for landings and takeoffs, often face challenges due to limited capacity, leading to performance degradation and significant environmental footprint. While existing Key Performance Indicators (KPIs) effectively assess the en route phase of flight journeys, there remains a gap in the metrics specifically designed for evaluating TMAs.

The purpose of this thesis is to develop a comprehensive evaluation framework tailored for TMAs to assess performance, identify inefficiencies, and highlight areas for improvement. First, the existing general metrics were modified for TMA-specific evaluation, proved effective in detecting inconsistencies in air traffic control and identifying optimization opportunities. New TMA-specific performance indicators were also developed and applied to various TMAs with different types of arrival procedures.

In the second phase, dependencies between the metrics were examined to create a performance assessment tool tailored to specific operational scopes. Statistical Ordinary Least Squares (OLS) analysis was performed on two subsets of metrics, uncovering that the newly-introduced metric, ‘threshold,’ correlates significantly with other performance indicators. This metric serves for the predicting TMAs performance based on entry conditions, improving air traffic management.

Recently, the focus was placed on Point Merge-specific metrics to assess their potential in improving environmental efficiency of the arrivals. Testing across seven airports revealed that Point Merge (PM) structures are often underutilized. Finally, the PM-specific metrics and the overall performance evaluation framework were refined for more efficient evaluation and further optimization of TMAs featuring different types of arrival operations.

I takt med att volymerna av flygtrafik ökar har det blivit avgörande att förstå och hantera trafikflöden inom TMA för att möta de växande kapacitetskraven. TMA, de luftrum som omger flygplatser och där flygtrafikledning (ATC) hanterar landningar och start, står ofta inför utmaningar på grund av begränsad kapacitet, vilket leder till prestandaf örsämring och en större miljöpåverkan. Medan befintliga nyckeltal (KPI) effektivt bedömer den flygande fasen av flygresor, finns det fortfarande ett gap i mått som specifikt är utformade för att utvärdera TMA.

Syftet med denna avhandling är att utveckla en omfattande utvärderingsram skräddarsydd för TMA för att bedöma prestation, identifiera ineffektivitet och belysa förbättringsområden. Befintliga allmänna mått har modifierats för TMA-specifik utvärdering och har visat sig effektiva för att upptäcka inkonsekvenser i flygtrafikledning och identifiera optimeringsmöjligheter. Nya TMA-specifika prestationsindikatorer har också utvecklats och tillämpats på olika TMA med olika ankomstprocedurer.

I den andra fasen undersöktes beroendena mellan måtten för att skapa ett prestationsbedömningsverktyg anpassat för specifika operationella områden. Statistisk OLS-analys genomfördes på två delmängder av måtten, vilket ledde till introduktionen av en ny metrisk, ’tröskel’, som korrelerar signifikant med andra restationsindikatorer. Denna metrisk hjälper till att förutsäga TMA prestation baserat på ingångsvillkor, vilket förbättrar hanteringen av flygtrafik.

Nyligen har ytterligare fokus lagts på Point Merge-specifika mått för att bedöma deras potential. Testning över sju flygplatser visade att PM-strukturer ofta är underutnyttjade. Slutligen förfinades de PM-anpassade metrikerna och det övergripande utvärderingsramverket för en mer effektiv framtida utvärdering och ytterligare optimering av TMA med olika typer av inflygningsoperationer.