Free routing in high-complexity airspace: impact assessment for environment and aviation stakeholders

Abstract

Global warming is an important phenomenon that is threatening the Earth and the living beings on it. It is affected by the human factors such as fossil fuels, exploitations of forests and livestock. Aviation industry has a part on producing the greenhouse gases causing the climate change. The industries contribution is around 5% to the global warming and it is expected to increase over time regarding its growth. Which is why many organizations are taking action to reduce and mitigate the effects of the aviation to earth temperature. Flightpath 2050 is a documentation for targets defined to reduce the aviation sector's contribution to the climate change. NextGen, SESAR can be counted as initiatives found for the aim. CLIMOP is a project that is coming up with operational improvements aiming to mitigate the climate effects of aviation. There are diverse studies and ideas focusing on reducing aviation's involvement in the long term and short term. While long term mitigations take time for implementation, short term improvements take an important role for reducing overall impact on the climate.Free Routing Airspace is one of the operational improvements that can be counted. Free Routing Airspace (FRA) is a concept introduced by SESAR as an operational improvement and it is defined as an airspace where the users can fly flexible routes with only entry and exit points defined. Evident option to choose in a FRA is the Direct Routes, where the direct path between the entry and exit points is followed by the aircraft. In this study the difference the Direct Route concept makes is assessed considering diverse stakeholders in aviation. Firstly, a high complexity airspace in the ECAC area is selected: EDUU controlled by DFS. It is observed that the air traffic is dense and complex in the area. It is selected as a demonstrative sample of flights to do the comparison. Second, baseline and direct route trajectories are generated using the Trajectory Generation Tool. For the baseline trajectories, ALLFT+ data from EUROCONTROL's DDR database is used and for the direct routes the trajectories are generated directly from the entry and exit points. Then, the different KPIs affecting multiple stakeholders in aviation are determined. The stakeholders are counted as the airlines, passengers, ATC officers and evidently the climate. The KPIs are defined as ATCo workload, number of movements, number of conflicts, routing efficiency, fuel consumption, travel duration, direct operating cost and the greenhouse gas emissions. Emissions of CO2, NOx and H2O are taken into account for the study considering their long-term effects on the earth temperature. xix Once the KPIs are calculated using the models constructed for the baseline and direct route trajectories, the results are compared. It is seen that applying the direct route concept is beneficial for all stakeholders in aviation and it is also better for the climate effects of the industry. This thesis, assesses and compares the impact of the Direct Route application to a high- complexity air space and it demonstrates the improvements that are possible through the practice. It is hoped to serve as a guidance point following the path of optimizing for climate in aviation.