After two decades of attempts to improve the performance of Europe’s fragmented air traffic network through better airspace integration, the EU’s legislative bodies have reached a provisional agreement that could finally lead to the substantial carbon emission savings, by as much as 10%, offered by the reform. First launched by the European Commission in 1999, the Single European Sky initiative has faced procrastination and delay, not least by a number of EU member states seeking to maintain their national interest, particularly over air navigation charges. Under the agreed reform, the aim is to increase Europe’s constrained capacity, lower navigation costs and increase the adaptability of the airspace system, while also reducing aviation’s climate impact. The agreement has been welcomed by air navigation service providers but representatives of Europe’s airline industry fear the reform will not go far enough.

“I am delighted with this result, concluded under our presidency, which will enable major progress to be made in reducing CO2 emissions from the aviation sector, and will also give member states more tools to limit the nuisance generated by aeronautical activity,” commented Belgium’s mobility minister, Georges Gilkinet, in a Council statement. “Although much remains to be done to help the sector achieve carbon neutrality, and we will continue to work towards this, the efforts made by all parties to bring this new legal framework for Europe’s skies to a successful conclusion are to be applauded.”

The text agreed by the Council, representing EU member states, and the European Parliament provides for binding targets and incentives to make flights more efficient and climate friendly, with an independent and permanent advisory Performance Review Board (PRB), set up under the regulatory EU Aviation Safety Agency (EASA) and funded by the EU, to help the Commission and states take decisions on the implementation of these plans. The Commission will adopt EU performance targets on airspace capacity, cost efficiency and climate and environmental factors for air navigation services, with performance reviewed at least every three years.

The Commission will also be required to conduct a cost-benefit study to help define how charges levied on airspace users – airlines or private aircraft operators – for the provision of air navigation services could encourage them to use the most fuel-efficient routing available and/or clean propulsion technologies. Mandatory modulation of en route charges will be introduced to encourage users to support improvements in environmental and climate performance.

The deal also provides the potential for more competition in the air navigation services market. It also requires member states to designate a national supervisory authority (NSA) to assess compliance of air navigation service providers (ANSPs) with economic requirements, such as financial sustainability and organisational structure, in cooperation with the national competent authority in charge of ANSP certification. The NSAs and the Commission are together to assess the performance of air navigation services “in accordance with the subsidiarity and proportionality principles”.

Following the introduction of the Single European Sky (SES) initiative in 1999, two legislative packages were adopted: SES I in 2004 and SES II in 2009. The Commission presented a revision in 2013, the SES 2+ package, which was adopted by the Parliament in a first-reading position in 2014, but the Council could not agree a complete position and an upgrade was subsequently proposed by the Commission in 2020.

The new provisional agreement is now subject to approval by member state representatives through the Council, the European Parliament’s transport committee and the full Parliament before the draft legislative acts are formally adopted by the co-legislators.

“The deal signifies a shift towards efficiency and sustainability in air traffic management. The current nationalistic airspace architecture hampers progress, leading to longer flights, increased emissions and unnecessary costs,” said Marian-Jean Marinescu, the Parliament’s lead rapporteur on the SES file, in a statement. “It’s high time to finally prioritise efficiency over nationalism, to pave the way for safer, more cost-effective and environmentally-friendly air travel in Europe.”

The agreement has been welcomed by CANSO, the trade body for ANSPs, which said it hoped the legislation would help the EU achieve its “seamless skies” ambition.

“We note that SES 2 will introduce mandatory modulation of en route charges to encourage airspace users to follow fuel-efficient routings, subject to a cost-benefit analysis,” said CANSO. “We call for this to encompass the principle of revenue neutrality for ANSPs, so that they receive the same fees for the provision of their services. It will be important for ANSPs to be able to balance offering environmental routings with the provision of capacity to airspace users.”

Added CANSO Director Europe Affairs Tanja Grobotek: “We look forward to receiving and analysing the final text. CANSO stands ready to provide support to the EU institutions when they draw up the implementing legislation to ensure there is a common interpretation, legal certainty and efficient implementation.”

However, Ourania Georgoutsakou, Managing Director of Airlines for Europe (A4E), expressed doubts over the package. “We are currently digesting the final agreement. We have been consistent in calling for a SES that delivers for airlines, passengers and the planet. On first look, it seems this agreement is still some way off this,” she said. “This will not be the end of A4E’s efforts to achieve a seamless, digital and a truly Single European Sky that will reduce delays, improve efficiency and reduce carbon emissions.”

A4E has concerns over the scope and independence of the PRB, with states potentially having the opportunity to influence the body and reduce the chance of actual improvements. It questions whether the PRB and/or NSAs will have enforcement powers and whether states can determine and also deviate from targets as they wish.

The European Regions Airline Association (ERA) described the provisional agreement as disappointing and a missed opportunity. “Based on ERA’s initial assessment, and subject to a detailed and thorough review, it is understood that this agreement does not go far enough to address the needs of Europe’s regional airlines, the needs that ERA has consistently advocated for since the Commission published to recast proposal in 2020,” it said.

Added ERA Director General Montserrat Barriga: “At first glance, several concessions appear to have been made that unfortunately reduces the likelihood of the substantial improvements that we have pushed for in terms of airspace capacity, operational efficiency and sustainability. It’s clear that further efforts will be required to address today’s aviation challenges effectively.”

Eurocontrol’s latest flight trends forecast shows the number of flights in the 44-state ECAC region is likely to reach 10.6 million in 2024, a growth of 4.9% compared to 2023 and accounting for 96% of 2019 levels. It expects this trend to continue, with an increase to 10.9 million (99%) in 2025, and further to 11.2 million (101%) by 2026. Beyond 2025, and subject to political and economic uncertainties, flight growth is expected to average 2.0% per year, rising to over 12 million flights in 2030.

Photo: The Bremen air traffic control centre (© DFS Deutsche Flugsicherung GmbH) 

To coincide with the European Commission’s ‘Connecting Europe by Air: the Green Transformation’, event held in Lyon, France, ten flights operated by six European airlines departed Lyon Saint Exupéry Airport fuelled with a 30% blend of sustainable aviation fuel produced and supplied by TotalEnergies. A number of incoming flights to Lyon followed unrestricted, fully-optimised routings to demonstrate fuel and emissions savings as part of the European SESAR’s ALBATROSS project. As well as the flights, the airlines showcased other sustainability measures including reduced single-use plastics, crew uniforms made from recycled plastic bottles, sustainable catering and offsetting of emissions through certified climate projects, while trade body Airlines for Europe (A4E) promoted the industry’s Destination 2050 roadmap to net zero emissions. Lyon Airport has a goal to become the first commercial airport in France to reach net zero carbon emissions by 2026 within the scope of its business. During a high-level debate at the event, Transport Commissioner Adina Vălean reiterated the EU’s strong support for ICAO’s CORSIA carbon offsetting scheme.

“Despite the current challenges our sector is facing, operationally in the wake of the global pandemic, geopolitically and with rising costs – airlines’ commitment to sustainable air transport is stronger than ever,” said Thomas Reynaert, Managing Director of A4E.

Commenting on the Lyon flights, he added: “Under real operational conditions, we’ve demonstrated that increased SAF uptake and more efficient air traffic management in Europe can reduce CO2 emissions by more than 30% per flight.”

The SAF for the flights was produced from used cooking oil (UCO) at TotalEnergies’ La Mède biorefinery in southern France and, claims the company, reduces lifecycle emissions by 91.2% over its fossil-based equivalent. Briefing reporters at the event, Strategy & Sustainability Development Manager Stéphane Thion said worldwide feedstock supply for SAF was limited and production was reliant on imported UCO, mainly from Asia, and other wastes and fat residues. The transportation of feedstocks from abroad was taken into account when calculating lifecycle emissions reduction, he added.

Thion said SAF production would total around 100,000 tonnes in 2022, with a target of reaching 300 million tonnes, or 65% of total jet fuel consumption, by 2050. A big jump, he admitted, but could be achieved through the twin levers of legislation and incentives to reduce the four to five times price gap, together with the appetite and need by airlines to decarbonise their activities.

Fatima da Gloria, VP Sustainability at Air France-KLM, two of those airlines taking part in the SAF uptake at Lyon, said worldwide SAF supply was very low, given the problem of economic viability and a lack of availability of high-quality feedstocks that were not in competition with food. She thought that in time, bio-based SAF will come closer to price parity with conventional jet fuel but would be restricted by the availability of biomass, whereas advanced non-bio fuels will still be four to five times more expensive by 2030.

“We will need prioritisation of feedstocks for the hard-to-abate aviation sector as it is important to remember that every industry is going through decarbonisation,” she said, echoing the call for government and investor support to boost SAF production and narrow the price gap. She also expressed concerns over EU policies leading to carbon leakage and competitive distortions with airlines outside Europe, but welcomed moves to introduce SAF allowances, which could be granted to airlines through the EU ETS in return for uplifting SAF.

Other airlines taking part in the Connecting Europe industry showcase included Lufthansa, Transavia, Vueling and easyJet. Three of easyJet’s flights departing from Lyon uplifted SAF-blended fuel, with an incoming flight from Lisbon following a specifically designed, optimised flight plan to demonstrate the potential for significant CO2 savings if the Single European Sky was implemented. The flight used airspace normally reserved for military purposes to achieve a direct routing.

The SESAR ALBATROSS project is conducting hundreds of gate-to-gate flight trials across Europe to demonstrate how optimised ATM operations could reduce average CO2 emissions per flight by 5-10% (0.8-1.6 tonnes) by 2035 through enhanced cooperation. Although the Commission has pushed for a Single European Sky, a number of EU member states remain opposed to the move, largely on sovereignty grounds.

“Our airline has committed to net zero by 2050 when we joined Race to Zero last year. We also recently published our ‘35% by 2035’ interim target,” said Thomas Haagensen, Director Group Markets and Marketing at easyJet, who also oversees sustainability at the airline’s board level. “In order to reach this, different elements will play a role and some were showcased on our Lyon flights: we need airspace modernisation –  our SESAR-optimised flight showed what is possible – and we require affordable SAF at scale.

“Full decarbonisation cannot happen without government support, finally implementing the Single European Sky and incentivising new technologies.”

Speaking to GreenAir on the sidelines of the Lyon event, Haagensen said easyJet was supportive of SAF use in helping to reach its net zero target. “But we are quite different from other airlines, in particular the traditional and long-haul carriers,” he added. “For them, SAF is a long-term solution whereas for us, it is an interim solution. We know that by 2035 there will be net zero technology that we can transition to, which is the end game for decarbonisation. With hydrogen and electric for short-haul, we will have that as a feasible option.”

The low-cost carrier is working with a number of industry partners, including Airbus, Rolls-Royce, GKN Aerospace, Cranfield Aerospace Solutions and Wright Electric, to accelerate the development of zero carbon emission aircraft technology and the required infrastructure.

“These technologies are becoming much more tangible. We know they will come and we now need to prepare the supply chain and the infrastructure to make this happen, including the production of green hydrogen,” said Haagensen.

“We are not technology providers – our aim is to acknowledge our impact on the climate, support measures like the EU ETS and stimulate the industry, as we have with startups like Wright Electric. What we can provide is commercial expertise so that they focus on the right segments as well as providing, for example, the flying knowhow of our pilots and helping them to attract more investor funding. We don’t invest our own money but we do invest a lot of our time with them. That’s what our partners ask us for.”

Speaking in a high-level panel debate, EU Transport Commissioner Adina Vălean described the aviation sector as progressive and cutting edge. “There is a clear path to net zero that everyone involved is supporting and I’m sure the industry will achieve it,” she said. “While we will have to wait until 2035 for the disruptive technologies to arrive, sustainable aviation fuels will provide the low-hanging fruit, although we will have to work hard to create a market for them and for the prices to drop. We will also need a more efficient and optimised air traffic system.”

On global aviation issues, Vălean said it was difficult to convince international institutions like ICAO to be progressive. “What is important from my perspective right now, however, is that we must apply CORSIA because this is what we agreed at an international level. If everyone applies it, then it will be a success and we will see a reduction in global CO2. We are also engaged in supporting the international deployment of SAF, even though there are different interpretations of SAF around the world.”

In regard to reaching an agreement on a long-term decarbonisation goal at the ICAO Assembly in the autumn, Vălean said: “We will do our best to convince our international partners to raise the level of ambition. However, we have seen that even if commitments are not being signed, things are happening, for example around SAF, so we have to understand the different approaches on the international stage. We will step up our diplomacy at ICAO though to get a higher ambition agreed and supported.”

Photo (easyJet): Refuelling of easyJet Airbus aircraft at Lyon with SAF blend supplied by TotalEnergies

The European aviation sustainability Destination 2050 initiative identifies a route to achieving net zero CO2 emissions by 2050 through a combination of four key measures. These comprise: Improving aircraft and engine technologies, which could achieve emission reductions of 37%; using sustainable aviation fuels (SAFs), estimated to achieve emission reductions of 34%; implementing economic measures, contributing 8%; and improving air traffic management and aircraft operations, expected to achieve emission reductions of 6%. Air traffic management (ATM) uniquely provides an opportunity to deliver fast, measurable gains to help to meet interim targets in the next 15 years, writes Jenny Beechener. Measures already underway as part of the European Commission Single European Sky (SES) initiative – recently updated in September 2020 to take into account the objectives of the Commission’s Green Deal – have actually accelerated during the recent period of low traffic.

European air navigation service providers (ANSPs) have implemented more than three quarters of initial Free Route Airspace (FRA) – mandated by the end of 2022 under EC SES Implementing Regulation (EU) No 116/2021. While traffic flows must still be segregated for safety reasons, the FRA environment allows airspace users to plan more efficient flight paths between defined entry and exit points thanks to a reduction in intermediate waypoints. Eurocontrol estimates once free route airspace is fully implemented Europe-wide, potential savings could reach 3,000 tonnes fuel/day and 10,000 fewer CO2 tonnes/day.

Taking advantage of quiet skies, ANSPs managing the European core area introduced FRA in the region’s busiest airspace to enable airspace users to file optimised flight-plans and route profiles. Airspace users gained access to FRA on many night networks in addition to FRA around the clock in upper airspace controlled by Maastricht (since December 2019) and Karlsruhe (since February 2021) control centres, with major centres in both France and Switzerland preparing to implement similar procedures from the end of 2021.

The traffic downturn and increased availability of air traffic controller expertise during the pandemic enabled implementation of further airspace management projects aimed at building better foundations for sustainable operations going forward. ANSPs operating within Functional Airspace Block Europe Central (FABEC) airspace, an area handling more than 55% of European flights, removed over 500 flight level caps and air traffic flow and capacity management measures in the first six months. These measures are used to manage traffic during periods of high demand.

In addition, airspace users saved on advice of FABEC air traffic controllers 68 million track miles during the actual flight compared with filed airline flight plans, reducing carbon dioxide emissions by 1.4 million tonnes. By the end of 2020, horizontal flight efficiency in FABEC airspace reached 97.06%, exceeding SES performance targets and close to the optimum possible.

The challenge is to maintain the shorter flight-plannable route options as traffic returns, prompting several new initiatives involving neighbouring ANSPs. Among early measures, ANSPs in Switzerland and Germany shortened routes over the Alps by 15 nautical miles in June 2020, saving flight time and reducing fuel consumption. Flights destined for northern Italy now follow a more direct route across central and southern Germany, and similar changes are being considered for flights from north east Europe destined for airports in Spain and North Africa. The two ANSPs also introduced permanent procedures that enables airspace users to remain at fuel-efficient cruising heights for longer and to reach higher altitudes earlier across the international boundary. Flight arrivals cross the border 2,000-4,000 ft higher than previously and Frankfurt departures entering Swiss airspace are no longer held at FL320 but can enter at any altitude, generating an average saving of 32kg of fuel or 100kg of carbon dioxide per flight.

Graph showing the vertical profiles of daily Frankfurt departures to the south via Zurich ACC before (in red) and after (in green) the introduction of new cross-border procedures between Germany and Switzerland, saving 100kg of CO2 per flight.

New sector boundaries are being introduced as part of the Cooperative Optimisation of Boundaries, Routes and Airspace (COBRA) project. COBRA aims to reduce complexity and provide more efficient traffic management by replacing coordination between multiple sectors with bilateral handovers and the provision of new route options. For example, shorter routes along the Karlsruhe – Maastricht boundary simplify connections between adjacent approach centres and improve vertical profiles for several arrivals and departures to and from hub airports in the core area of Europe. The procedures are supported by validation simulations, controller training and new concept of operations with implementation expected in 2022. Maastricht Upper Area Control Centre (MUAC) is also engaged in a sectorisation review to identify improvements to flight planning which aims to deliver further network improvements in 2021/22.

Since March 2021, MUAC airspace sector organisation is better suited to the European concept of free route airspace and ready to support higher traffic levels as soon as commercial schedules resume. Benefits include a reduction in flight planning restrictions and the creation of several shorter flight-plannable route options. Simulations predict that on the basis of pre-pandemic traffic, the change will bring a weekly CO2 saving potential of 6,700 kg and offer flight-plannable gains of 280 nautical miles.

While these measures aim to save flight miles and reduce carbon emissions, other greenhouse gas emissions such as NOx and particulate matter provide the focus for separate ATM research. Preliminary findings show about half the climate impact of aviation originates from non-carbon dioxide effects of kerosene use, including the soot particles emitted from aircraft that lead to formation of contrails. The SESAR Exploratory Research project FlyATM4E is investigating the impact that weather situations and aircraft trajectories have on the formation of contrails and their persistence. The research partners aim to develop a concept to identify climate-optimised aircraft trajectories to enable an eco-efficient reduction in aviation’s climate impact, taking into account the balance between contrail avoidance and additional fuel burn.

In a practical application, MUAC is examining how relatively minor operational measures such as small flight level changes, for example diverting aircraft 2000 ft up or down from their normal flight path, can reduce persistent contrail formation and contrail cirrus. The trial includes creating a contrail prevention system; implementing operational procedures for contrail prevention; and the validation of the methodology with satellite image analysis by the project partner DLR.

Engaging with airspace users and ensuring network constraints are kept to a minimum are key steps in ensuring airlines take advantage of more efficient flight trajectories, enhance fuel efficiency and lower emissions. However, to be successful these measures depend upon more than just ANSP activities. Pan-European agency Eurocontrol published an assessment of benefits arising from operational ATM improvements examining fuel burn from take-off to landing across the whole ATM network in December 2020. The report concludes that reducing air transport emissions by up to 10% requires different tools, policy measures and the full collaboration of all the various involved aviation stakeholders. It emphasises the need for collaboration in the roles and responsibilities of each operational stakeholder, from ANSPs to airlines, including airports and the Network Manager, through mechanisms such as collaborative decision-making (A-CDM).

Photo: Eurocontrol Maastricht Upper Area Control Centre

About the author

Jenny Beechener

Jenny is a freelance airspace management writer covering manned and unmanned air traffic sectors. Previous roles include Editor of Jane’s Airport Review, Editor of Jane’s Air Traffic Control and Managing Editor of Air Traffic Management. She can be contacted at jennifer.beechener@btinternet.com.