SESAR has been underway for twenty years, but progress towards simplifying European airspace and routes is yet to fulfill its original goals. Its critics believe it is unlikely to gain ground at the desired pace in the future.
The fundamental challenge is airspace fragmentation. There are more than 40 different bodies governing airspace guarded by national sovereignty, making it difficult to create routes that go directly without doglegs. Inefficiency increases fuel burned by airlines by 8.6 to 11.2%.
Europe has given up on the idea of creating functional airspace blocks to consolidate control, while the areas targeted remain under the control of several ANSPs, not just one.
“It has been 20 years since the first Single European Sky regulation,” says Marina Efthymiou, professor of aviation management at Dublin City University in Ireland. “There has been some progress, but it hasn’t delivered on what was originally envisioned.”
Efthymiou edited a book, “Air Traffic Management: Principles, Performance, Markets,” published in 2023, that examined the status of ATM reform in Europe. She contributed to several of the dozen or so chapters written by European academics and ATC operations professionals. She is an expert evaluator for the European Commission and has been involved in projects such as the ICAO Action Plan and has written more than 40 papers on aviation management subjects in the past five years.
In the foreword to the book, Patrick Ky, the then executive director of EASA, writes: “The ATM / Air Navigation Services (ANS) sector is still functioning on the same principles as 70 years ago.”
“The exception is a few remarkable but limited developments in Europe, led by European institutions,” he writes. These include the Central Flow Management Unit at EUROCONTROL headquarters in Brussels, Belgium, the Network Manager for Air Traffic Flow Management and SESAR in research, regulation reform and performance reviews.
“Apart from the Maastricht (Upper Area Control) Center, the core ANS services: communications, navigation, surveillance (CNS) and air traffic services (ATS) have not seen much progress towards enhanced organisational setup at the European level,” Ky says.
Maastricht UACC handles traffic for Belgium, Luxembourg and the Netherlands. In addition, the COOPANS Eurocat ATC system provided by Thales involves a long-term partnership between the IAA of Ireland, LFV2 of Sweden, Naviair of Denmark, Austro Control of Austria and Croatia Control using the same system supplier. COOPANS started in 2006. The Eurocat ATC system is operational in the five national airspaces and controls more than 1.3 million flights per year.
Cost vs Quality of service
In 2019, Eamonn Brennan, the then director general of EUROCONTROL, raised the question: “Airlines are charged billions of Euros for ATM services but are they receiving billions of Euros worth?”
In 2018, the total European ANSP en route and terminal costs reached €8.4 billion (US$9 billion) according to EUROCONTROL. Of these costs, 65% are for staff, while only half of that workforce is engaged in ATC operations.
Another big impediment to progress is that states have been hesitant in unbundling CNS services, according to Efthymiou. There is a lot of complexity in ATM reform and significant investments are required to make it happen. Politics also plays a key role. “The states involved have not been willing or able to step up and make the necessary investments,” she says.
“It is very difficult to have ANSPs cooperate in different ways than they want to,” says Efthymiou. “The pandemic provided a significant opportunity for Europe to change routes without incurring capacity problems and delays. They could have redesigned several things.”
Now traffic is ramping up. Spain is already handling more traffic than before the pandemic. In places such as Belgium and the UK, capacity and delay problems are already developing.
Efthymiou adds that Europe has the same type of air traffic controller shortage that the US is experiencing. In both regions, retirements from an aging workforce are rising, while people are leaving to take higher-paid jobs in Middle Eastern countries. ANSPs handle controller hiring in different ways, and it is difficult for controllers working outside of the EU to get hired or to move from one EU nation to another. EASA wants to simplify licensing of controllers and recognize licenses from nations outside the EU.
However, Europe hasn’t had a rash of close-call runway safety incidents like the ones that have occurred in the USA, which have raised questions about controller shortages and training.
But there have been technical problems in Europe. Air traffic became snarled up in the UK on August 28, 2023 – a key holiday travel period – when a flight plan processing sub-system and its backup entered a fail-safe mode. The glitch occurred after a flight plan included two identically named but separate waypoints outside of UK airspace. When the automated systems went down, controllers were only able to handle a small fraction of the traffic needing services. Aircraft in the air continued their journeys, but most on the ground were kept there. It was the first and only time the glitch had happened during five years of service. The system processes around 15 million flight plans a year.
In March 2024, an independent review panel delivered an interim report on the NATS failure. The report says the cause of the failure is understood, but the investigation is seeking additional evidence. UK regulator the Civil Aviation Authority estimates that more than 700,000 passengers were affected – 300,000 with cancellations and 95,000 were delayed more than three hours, and the remainder had shorter delays.
The UK review panel is also exploring ways to improve the aviation system. “This report contains damning evidence that NATS’ basic resilience planning and procedure were wholly inadequate and fell well below the standard that should be expected for national infrastructure of this importance,” says Tim Alderslade, CEO of trade association Airlines UK.
Environment and economic pressure
Economic regulation of air traffic in the EU, and whether input or output should be charged, is another important question. “Are you looking for results or the way results are being generated?” asks Efthymiou.
Authorities are examining the possibility of using modified service charges for aircraft operators which would vary depending on the environmental footprint of the airlines. If an airline produces higher emissions, it would be required to pay more. There is big opposition to this concept from airlines in Europe. “The regulators may charge an aircraft operator less if it uses SAF, which doesn’t make much sense,” says Efthymiou.
She notes that the effect of the European Green Deal on aviation is not going to do much to optimize air traffic movement with its focus on the type of fuel used. The Green Deal adopted by the European Commission (EC) calls for transportation policies to reduce net greenhouse gas emissions by at least 55% by 2030 compared to 1990 levels.
A briefing paper on the Single European Sky 2+ package by the EU Parliamentary Research Center published in April says the aviation sector in the EU provides nearly five million jobs and contributes €300 billion – 2.1% – of the EU’s gross domestic product.
In 2018 1.1 billion passengers were transported by air. EUROCONTROL helped manage 11 million flights in 2019 before the pandemic caused a historic drop. Before the drop-off, traffic peaked at 37,000 flights per day. This was four times more than 35 years earlier when EUROCONTROL was founded.
“The Single European Sky attempts to replace EU member states’ national airspace management systems with an organisation ally and technologically integrated pan-European system.
“So far, however, the outcome has not matched the level of initial ambition,” writes Jaan Soone of the Parliamentary Research Centre in the paper.
The SES 2+ package was adopted by the European Parliament in 2009. It aimed to tackle substantial air traffic growth while increasing safety, reducing costs, delays, and air traffic’s environmental impact. The EC has concluded that updating the SES regulatory framework could at the most only help reduce up to 10% of air transport emissions. Despite these initiatives, ATM in Europe remains fragmented, costly and inefficient, Soone writes. Functional airspace block formation was delayed and those created are not functioning effectively and don’t deliver synergies and economies of scale.
The EC has also introduced the possibility that a common unit rate for en route navigation services could be implemented in SES airspace. Currently, unit rates that an aircraft operator pays per kilometre in each airspace vary from one country to the next.
A single-unit rate was originally proposed 20 years ago and was shelved, but has now reemerged. “It may sound ideal, but it would be difficult to implement,” Efthymiou says. “There would be winners and losers. Powerful ANSPs with a lot of traffic and high unit rates including the UK, Spain, Italy and Switzerland would lose, while ANSPs in cheaper airspace operations such as Greece and Croatia would win. And how do you define an average service charge?”
Efthymiou and Keith McEvoy, a deputy operations manager at Dublin, write in one essay that most ANSPs feel functional airspace blocks envisioned to create airspace unfettered by national boundaries have not worked but have little environmental benefit. Privatization is still rare among ANSPs, while airports and airlines have embraced a commercial, market-driven focus. The two write that Europe seems to be lagging in privatization compared to other parts of the world.
Future coordination
ANSPs were created as national monopolies within national borders but now the standards for good performance are different. At a time when aircraft operators and ANSPs are expected to operate more efficiently in terms of timing as well as reducing environmental impact.
“But they can’t perform well because of other types of restrictions, such as the type of ANSP ownership, the government behind it, the national borders, the role of the military, the architecture of the airspace and the processes in use,” says Efthymiou. “The single European Sky looks great on paper but it hasn’t had the progress that was expected. It is very difficult to make ANSPs cooperate and work in a different way than they want to.”
There is also a contradiction, she thinks, in saying that European ATM aims to reduce 10% in air transport emissions while at the same time looking to improve capacity to handle more traffic. “There is a contradiction in these performance measures. You can’t have the whole pie,” Efthymiou says.
“There is a lot of research still to be done on how operational efficiencies can be gained. For both ANSPs and aircraft operators there is a lot to be learned. They need to cooperate better and examine the trade-offs together in key performance areas.”
Efthymiou believes en route and terminal airspace should be separated in these analyses. In terminal services, introducing competition could improve the quality of services. “I am not saying that privatization is better because we have examples where privatization has happened, and the results have had terrible effects. In other cases, privatization including competition has produced good results. However, in some places national security and geopolitical restrictions mean that services need to be constituted as a state-run organisation.”
An interesting example of these tradeoffs is NATS in the UK. While it has some of the most expensive unit rates in Europe, the recent computer glitch aside, it provided a good quality of service, Efthymiou says. And it has an excellent safety record. Furthermore, NATS has introduced environmental performance measurements before the regulator demanded them. And in the UK, Deutsche Flugsicherung (DFS), the German ANSP, provides terminal services at Gatwick Airport.
Francois Huet, former policy and regulatory director for the Borealis Alliance with experience in the EC, EUROCONTROL and the SESAR JU, writes that ATM in Europe is at a turning point following the economic downturn, the pandemic, and the coming of new entrants: “In such a challenging context, European institutions and all stakeholders have agreed to embark on an ambitious transformation aiming at delivering by 2035 a digital European Sky.”
Digital ATM is considered by many experts as a prerequisite for handling uncrewed aircraft systems and eVTOLs in the same airspace with manned aircraft. Some experts, such as Anna Tomová, associate professor in transportation economics at the University of Žilina in Slovakia believes that Europe needs to adopt more radical changes to liberalize ANSPs. Tomová wrote the chapter on structural reform in the ANSP industry.
Another study that Efthymiou was involved in suggests there should be some mandatory environmental training for pilots to obtain a commercial license. And air traffic controllers may need to undergo similar training. She also suggests environmental issues should be considered in the design of air traffic procedures.