Green operations with geometric altitude, advanced separation and green route charging solutions
Green-GEAR
Visualization of Air Traffic Over Europe
This striking visualisation showcases the growing density of air traffic across Europe. The intricate network of flight paths highlights the increasing challenges of airspace management, particularly when it comes to maintaining safe vertical separation between aircraft. One of Green-GEAR’s three solutions is exploring whether geometric altimetry could help address this issue, improving both the efficiency and sustainability of air travel.
Credit:
Copyright NATS
The Green-GEAR project is working on advancing aviation technology to improve environmental responsibility, safety and efficiency. Traditional barometric altimetry, the long-standing method for measuring altitude in aviation, is limited by its general accuracy as well as sensitivity to weather-induced pressure fluctuations, leading to a lack of direct terrain reference.
Solution 1 - GeoAlt To address these challenges, Green-GEAR’s Solution 1 - GeoAlt explores the introduction of geometric altimetry, i.e. satellite-navigation-based altitude measurements, to provide more unified altitude measurements across the network. This innovation promises to enhance safety by removing the need for manual pressure reference adjustments and eliminating the transition layer*, while also enabling the seamless integration of traditional aircraft with emerging airspace users such as drones and high-altitude operations.
Solution 2 – Separation Minima In Solution 2 – Separation Minima, the project investigates the feasibility of reducing vertical separation minima in RVSM airspace from 1000 feet to 500 feet. By leveraging geometric altimetry’s precision, this approach could significantly expand airspace capacity, allowing more aircraft to operate at optimal flight levels and reducing emissions from less efficient routing.
Solution 3 - Green Route Charging Green-GEAR’s solution 3 – Green Route Charging is introducing a new concept to incentivise climate-conscious airspace use. This scalable mechanism adjusts en-route charges to encourage more environmentally responsible flight paths while maintaining revenue neutrality for air navigation service providers and overall cost neutrality for airspace users.
Coordinated by the DLR Institute of Flight Systems, Green-GEAR brings together a consortium of leading aviation stakeholders Airbus, Eurocontrol, NATS, NLR as well as academic partners the University of Trieste and the University of Westminster. Running from September 2023 to February 2026, the project is funded by the European Union (Grant No. 101114789) and UKRI for UK participants.
By fostering innovation in geometric altimetry and route optimisation, Green-GEAR contributes to making aviation more efficient and environmentally sustainable.
*The transition layer is the airspace between the transition altitude (where during climb pilots switch the barometric pressure reference from the local measurement to an international standard setting for vertical navigation) and the transition level (where this switch occurs in reverse during descent). It creates complexity for navigation, as pilots must adjust instruments and altitude references, increasing the risk of errors and bringing inefficiencies in airspace use and flight profile design.
This project has received funding from the SESAR 3 Joint Undertaking (JU) under grant agreement No 101114789. UK participants NATS and University of Westminster receive funding from UK Research and Innovation (UKRI) under the UK government’s Horizon Europe funding guarantee [grant number 10087714 (NATS) and 10091330 (UoW)].
Participants
Deutsches Zentrum für Luft- und Raumfahrt (DLR), Airbus, Airbus Operations, Eurocontrol, Università degli Studi di Trieste, Stichting Koninklijk Nederlands Lucht - En Ruimtevaartcentrum (Royal NLR), NATS, University of Westminster
The project is supported by the SESAR 3 Joint Undertaking and its founding members. Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or SESAR 3 JU. Neither the European Union nor the SESAR 3 JU can be held responsible for them.
Supported by SESAR 3 JU and Co-funded by the European Union
