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1 – The air transport system and Clean Sky: the hub of Europe's aeronautical R&T

Clean Sky is the leading protagonist of Europe's aeronautical research and innovation, championing the air transport needs of tomorrow's increasingly mobile and growing population. It does this by acting as a hub - operating at the centre of a diverse universe of players across Europe, drawing in giants of the aero-industrial community and SMEs in their supply chains, pioneering research establishments, regulatory bodies and academia.

Clean Sky enables all these sometimes disparate and sometimes inter-competitive players to work collaboratively - funded through a public-private-partnership - on the design, demonstration and validation of novel technologies up to Technology Readiness Level 6 (TRL6) - technologies that will be, post-R&T, ripe for deployment in the aircraft we can expect to fly in, both in the near future and in the decades ahead.

But nurturing novel aeronautical tech is just half of Clean Sky's raison d'être.  

The 600+ entities that work collaboratively across 24 countries within Clean Sky's eco-system all share a unified vision – a common genetic marker in their DNA: They all strive to push aeronautical science beyond the limits of imagination by creating new technologies that significantly reduce aviation's impact on the planet.

And the cumulative effect of this collaborative and sustainable endeavour is to manoeuvre Europe's aeronautical research and technology capabilities into a strategically advantageous position within an increasingly competitive global landscape.

By reinforcing Europe's stature in aero-engineering science, Europe's aviation industry will be better placed to design, develop and deploy the next generation of aircraft products, create new employment opportunities, and bolster the economies of Europe. And simultaneously, Europe - and the rest of our planet - will benefit from cleaner skies.

But what is the context behind this grand plan; what are the forces at play - and how does Clean Sky fit into the complex universe of commercial aviation?

2 – Commercial aviation in Europe and beyond:

To appreciate Clean Sky's invaluable role in European aeronautics, it's useful to have a sense of the scale and complexity of commercial aviation, both regionally and globally.

In its latest Annual Review published in June 2016, IATA (the International Air Transport Association) stated that industry-wide revenue passenger kilometres (RPK) grew 7.4%, "the greatest increase since the rebound from the depth of the global financial crisis in 2010 and well above the long-run average of 5.5%. Altogether, more than 3.5 billion passenger segments were flown in 2015, an increase of 240 million compared with 2014."

And there's more good news for the sector: The average global passenger load factor (the percentage of seats filled in a plane) increased 0.6 % over the 2014 percentage to an all-time high of 80.4%, confirming a steady, healthy and continuing demand for air travel.

Furthermore, the opening up of new unique city-pair airline routes (direct flights between cities) is generating a corresponding increase in the flow of both people and cargo and saves time by eliminating connections, making the passenger journey smoother. Unique city-pair connections rose last year by 350 pairs, to reach 16,600, and what's even better for the consumer is the fact that in real spending terms, air fares cost us half of what they did twenty years ago.

Tourists travelling by air spent over $620 billion in 2015, but it's not just passengers that are benefitting: For business and international trade, aviation is vital for connecting supply chains and opening new markets. IATA calculates that "the value of international trade shipped by air in 2015 was $5.7 trillion".

By reading between the lines and crunching some of these statistics, this means that airlines are intelligently managing to supply more of the right number of seats on the right routes to meet an increasing passenger appetite for flying.

European commercial aviation has an increasingly prevalent and leading role within the wider global context of aviation, in terms of industrial growth and employment opportunities. Aviation is also a unifying force for collaborative efforts in terms of bringing neighbouring countries together in a common effort. And it's an effort that's paying respectable dividends.

Find out more about IATA

3 – Europe's growing slice of the aircraft manufacturing cake

Almost 10 million people work directly in the aviation industry worldwide, generating around 63 million jobs across aviation's broader universe of supply chains, air traffic management infrastructure, regulatory bodies and sales distribution channels.

This is partly because when it comes to longer and intercontinental journeys, there is simply no practical alternative to aviation on long and intercontinental routing. This is confirmed by data released by the Air Transport Action Group, which shows that more than 80% of passengers travelling through European Union airports were flying on international routes, almost half of them on transoceanic routes.

To quantify the scale of what's happening, the current aviation route networks include around 1400 airlines with a global fleet in excess of 25,000 aircraft, monitored and controlled by more than 173 air navigation service providers. The growth forecast for the next two decades indicates a need for over 32,000 new aircraft, with a total value of $4.9 trillion, including both fleet additions and replacements.

Impressive stuff, but here's the most remarkable part of all this:

Since the 1960s until the present, Europe has progressed from designing and manufacturing 10% to more than half the world's airline fleets across all segments of commercial aviation. And with the success of European aeronautics' burgeoning role in creating the airborne vehicles that facilitate this global mobility comes an increasing sense of responsibility in respect of aviation's environmental impact.

So how exactly does aviation affect our planet and what measures are being taken to protect the earth for our futures - and those of future generations?

4 – Aviation's impact: how the sector is taking responsibility

According to the Air Transport Action Group (ATAG), aviation is responsible for 12% of CO2 emissions from all transport sources - that compares with 74% from road transport - and accounts for around 2% of all humanly-generated CO2 emissions. In everyday terms, air travel's efficiencies are similar to those of a small car. 

In many instances, especially for intercontinental and long-haul journeys - as explained in the previous section - there's simply no practical alternative to aviation, particularly when it comes to transporting perishable freight. ATAG cites a good example of what's happening: "While air transport carries around 0.5% of the volume of world trade shipments, it is over 35% by value" - so, as ATAG points out, "deliveries of fresh produce from Africa to the UK alone supports the livelihoods of 1.5 million people, while producing less CO2 than similar produce grown in the UK, despite the energy used in transport".

In February this year, an aircraft CO2 emissions standard was unanimously recommended by the 170 international experts on the International Civil Aviation Organization (ICAO)’s Committee on Aviation Environmental Protection (CAEP), smoothing the path for its ultimate adoption by the UN agency’s 36-State Governing Council.

The new CO2 emissions standard would not only be applicable to new aircraft designs as of 2020, but also to new deliveries of current in-production aircraft types from 2023 onwards. In ICAO's sights are larger aircraft, for it is medium-to-large aircraft (planes weighing over 60 Tonnes) that generate over 90% of international aviation emissions.

“The goal of this process is ultimately to ensure that when the next generation of aircraft types enter service, there will be guaranteed reductions in international CO2 emissions,” stressed Olumuyiwa Benard Aliu, President of the ICAO Council. “Our sector presently accounts for under two percent of the world’s annual CO2 emissions, but we also recognise that the projected doubling of global passengers and flights by 2030 must be managed responsibly and sustainably.”

The challenge of curtailing aircraft emissions is of course part of an even broader and holistic effort to address all forms of climate impact - not just in aviation - and governments worldwide are actively undertaking measures in the form of agreements for action to ensure compliance with set targets. Last year's COP21 (the 21st session of the Conference of the Parties) agreement on climate impact imposed restrictions on human activities, aiming at limiting any increase to the Earth's average temperature to no more than 1.5 °C.

Aviation is not yet targeted by the latest COP21 agreement, which is part of the cycle of major United Nations conferences on climate change. Nevertheless, the aviation industry has, for some time, undertaken a technology development strategy geared at limiting its impact, thus mitigating emissions and noise - especially in and around airports.

So, what practical steps is the aviation industry taking to ensure that more people travelling in the skies doesn't mean an adverse impact on the planet?

Find out more about ATAG

Find out more about ICAO

5 – Capacity demand + eco-awareness = a need for better technologies

As the aviation industry thrives and passenger traffic doubles over the next twenty years, it's incumbent upon the aeronautical community to take responsibility by creating and cultivating powerful technologies that are environmentally benign.

It's therefore no surprise that, looking ahead to the future, there's going to be continuing demand from aircraft operators – mostly airlines - for novel aircraft technologies that burn less fuel (27% of an airline's costs in 2015 was fuel), that employ new aerodynamics in the wings to minimise drag and generate more lift, for systems that control the internal workings of the aircraft but are lighter - plus many other new technologies that create better efficiencies, reliability, cost savings and are of course eco-compliant with the ICAO rules and other environmental legislation affecting air travel.

And that's where Clean Sky comes in - in fact quite early into the process - advancing the research and technologies that will enable industry (such as airframe manufacturers and engine builders) to pick up and run with the baton - to take those novel technologies developed to TRL 5/6 through Clean Sky and to develop them to the next stages of development, certification, implementation and deployment into the aircraft that will carry tomorrow's passengers and cargo.

So how did Clean Sky come about, what is Clean Sky 1 and what are the unfolding ambitions of Clean Sky 2?

6 – Prelude to Clean Sky - ACARE and Flightpath 2050


Before we can actually look at the specifics of Clean Sky, we have to make a slight detour. Actually we need to rewind the clock back 16 years.

Back in 2000 the European Commission set up the Advisory Council for Aviation Research and innovation in Europe (ACARE) in order to provide design guidelines that could be commonly accepted across Europe's aviation sector as a basis for moving the industry towards greener standards.

It launched at the Paris Air Show in June 2001 with a mix of over forty member organisations and associations including stakeholders across manufacturing industry, airports, airlines, regulators, service providers, research establishments and academia.

ACARE was tasked with identifying long-term objectives for the European aeronautical industry in areas of environment, industrial competitiveness and societal benefits, and its members were selected from industry, research centres and academia, mandated with developing a Strategic Research Agenda (SRA) for European aeronautics.

The original SRA was, as ACARE describes it "a roadmap outlining the strategic orientations which should be taken if Europe is to meet society's needs for aviation as a public mode of transport as well as noise and emissions reduction requirements in a sustainable way". This was intended to meet Vision 2020, a set of goals set up around the same time as the inception of ACARE, and later superseded in 2011 by Flightpath 2050, together with its own associated Strategic Research and Innovation Agenda (SRIA) in 2012, building upon the previous one with updated objectives.

ACARE and Flightpath 2050 are part of a comprehensive family of initiatives in aeronautics and air transport including the EC’s Framework Programme research FP6, FP7 and Horizon 2020, as well as the SESAR Joint Undertaking.

SESAR has in its sights the implementation of the Single European Sky initiative, the aim of which is to overcome the current fragmentation of European air space, aiming at increased safety and more efficient routing, and working towards a new unified vision for Europe's disjointed Air Traffic Management infrastructure. After all, the whole point of Clean Sky developing new technologies for the next generation of aircraft could not reach its full potential if air traffic management lacks the capacity and efficiencies to get passengers where they need to go in the shortest, smoothest, quickest timeframe - without being stuck in holding stacks or waiting for take-off slots.

Therefore it could be said that Clean Sky and SESAR have a certain level of symbiosis and shared objectives - siblings in a family of Eco-sensitive initiatives.

One of SESAR's objectives is to contribute up to 10% of the ACARE emission-reduction goals and, through optimised take-off and descent approaches, to reducing perceived noise at airports. Some of these objectives can be achieved with the current in-service fleet, but it's new engines, wing aerodynamics and other Clean Sky technologies that will enable even more significant emission reductions and noise mitigation.

The definition and development phases of SESAR ran between 2007-2013, and have established the next generation of air traffic management systems, components and operational procedures. SESAR is currently in its deployment phase (2014-2020), which will see the large scale production and implementation of new air traffic management infrastructure foreseen in the Single European Sky Master Plan, bringing in time-saving initiatives such as Time Based Separation - already successfully deployed at Heathrow airport - and SWIM, the intranet of air traffic management, enabling seamless data exchange between all providers and users of aeronautical, flight, aerodrome, meteorological, air traffic flow, and surveillance information.

Clean Sky is the vital part of that wide-ranging set of Eurocentric initiatives with a focus on fostering new technologies that will make tomorrow's aircraft greener and more efficient.

What follows is how Clean Sky came about, how the original Clean Sky programme (henceforth known as Clean Sky 1) has and is enabling novel aeronautical research and technology to address the challenges of commercial aviation, and how the more recently launched Clean Sky 2 is setting its sights for the even more stringent environmental challenges of commercial flight in the 2025 to 2050 timeframe.


Find out more about ACARE

Find out more about SESAR

7 – Clean Sky 2 - a bigger leap into the future



Aeronautical research became part of the European Commission Framework Programme for R&D funding under FP2 (1987-1991) as a pilot scheme with a €2 million budget. Constant progress and efficacy has justified the growing presence of aeronautics within the European Commission Framework Programme for R&T funding. For example, European collaborative projects from the 5th (1998-2002), 6th (2002-2006) and 7th (2007-2013) Framework programmes have contributed substantially to technology development up to TRL 6 and have been deployed in large aircraft including the Airbus A380 and A350.

The Clean Sky JU was created as an act of the European Council in 2007 in the first wave of Joint Technology Initiatives (JTI), with the mandate of implementing an ambitious programme of environmentally friendly technology development, underpinned by a public-private collaboration between the Commission and Europe's aeronautical community.

JTIs are a key mechanism for performing research at EU level; they are long-term Public-Private Partnerships; and are managed within dedicated structures based on Article 187 TFEU (ex Article 171 TEC). The EU explains that JTIs “support large-scale multinational research activities in areas of major interest to European industrial competitiveness and issues of high societal relevance”.

The salient term here is “long-term”. For it’s the relatively long-term nature of JTIs that synchronises with the extended timescales that are typically required in commercial aviation - across research, design, technology demonstrators (in the case of Clean Sky), prototyping, development, manufacture, certification and deployment into service.

The first Clean Sky programme is entering its final months, and has exceeded the ambitious expectations set back in 2007. Having established and consolidated its credentials as a force for good in European skies, Clean Sky 2 is well under way with even loftier objectives.

In the Innovative Technologies section of our web site - a section which is evolving with regular updates as Clean Sky 2 gets underway - we introduce an array of ground-breaking new projects and their proposed demonstrators. These comprise radical approaches in areas of Large Passenger Aircraft, Regional Aircraft, Fast Rotorcraft, Airframes, Engines, Systems. In Clean Sky 2 the scope of innovative activity has been extended to include Small Air Transport too.

To summarise, with over 600 entities working collaboratively to pool expertise and resources, and a budget that's commensurate with the ambitions of creating greener and more effective technologies for the next paradigms of air travel, Clean Sky is successfully chaperoning aeronautical research and technology to where it needs to be for the challenges of European aviation – for tomorrow and beyond.