(All images and sources of information are credited to airbus.com)
In 2019, Airbus SE (Societas Europaea) became the world’s largest manufacturer of airlines, taking more orders than its major rival, Boeing. Over the course of 2019, Airbus delivered a whopping 863 planes to its worldwide customers, the greatest number of planes it has ever delivered in a single year, following two decades of constant increase in deliveries. (As you might expect, 2020 was an exception to this trend due to COVID-19 fallout, though there were few companies that didn’t suffer a drastic decline in business due to the pandemic.)
Airbus is a hugely note-worthy company in aviation not only because of its consistent display of dominance in manufacturing and delivering aircraft, but also because of its ability to adapt to the rapidly changing world in which we live. Airbus is at the very forefront of aerospace research and innovation, and hence, the exciting technologies being developed at Airbus are the topic of this article.
Part 1: Overcoming the Challenges of Today
In my opinion, two of the greatest current challenges in aerospace are: i) achieving net zero (carbon neutral) aviation, and ii) achieving autonomous commercial flight. Airbus is a key player in the global effort to fulfil both of these goals, but in this article, I am going to focus solely on Airbus’ efforts to decarbonise the skies, which is the most pressing current challenge in my opinion.
In order to achieve the European Commission’s Flightpath 2050 Vision – a reduction in CO2 by 75%, NOx by 90%, and noise by 65% – new technologies (of which electrification is one of the most promising in the short-term) are needed. In 2018, it is estimated that global aviation resulted in the emission of 1.04 billion tonnes of CO2. Along with the fact that making current technologies more efficient cannot achieve such radical reductions, it becomes clear that the innovation of any new technologies with the potential to reduce CO2 output from aviation is vital.
Zero-emission flight is much closer to realization than many people think. Airbus is continuing to develop, build and test alternative-propulsion systems – powered by electric, hydrogen or solar technology – to enable the aviation industry to reduce the CO2 emissions of commercial aircraft, helicopters, satellites and future urban air mobility vehicles.
To start, let’s look at electric technologies. Electric-powered propulsion is a very promising concept, particularly in the case of small aircraft. A timeline of Airbus’ ventures into electric flight is shown in the figure below.
One of the key milestones in Airbus’ decarbonisation journey was the E-Fan X demonstrator aircraft. Developed in 2017, it utilised a first-of-its-kind hybrid-electric propulsion system. A BAe-146 aircraft had one of its four jet engines replaced by a Siemens 2 MW electric motor, integrated alongside a 2-tonne battery. Although Airbus recently made the decision to bring the E-Fan X demonstrator project to an end in order to focus on new pathways for disruptive CO2 reduction, this project laid the foundations for the future industry-wide adoption and regulatory acceptance of alternative-propulsion commercial aircraft.
The Promise of Hydrogen
One of Airbus’ key ambitions is to develop the world’s first zero-emission commercial aircraft by 2035. Hydrogen will undoubtedly be a key factor in helping Airbus to achieve this goal, as it is a high-potential technology with a specific energy-per-unit mass three times higher than traditional jet fuel. If generated from renewable energy through electrolysis, it emits no CO2, thereby enabling renewable energy to potentially power large aircraft over long distances.
The main issue associated with hydrogen is storage. Not only is it highly flammable, but it has a very low volumetric energy density, which means that extremely large volumes of hydrogen need to be stored for the same amount of energy output. In order to accommodate for this, it is likely that the visual appearance of future aircraft will change radically, with bulkier storage solutions than existing jet fuel storage tanks.
Hydrogen has two potential uses:
1. Propulsion: Hydrogen can be combusted through a modified gas-turbine engine to produce direct propulsion or generate electrical power.
2. Synthetic fuels: Hydrogen produced using renewable electricity is combined with carbon dioxide to form a hydrogen-carbon fuel with net-zero greenhouse gas emissions.
All in all, hydrogen has the potential to reduce aviation’s CO2 emissions by up to 50%.
Solar panels allow an aircraft to have a continuous supply of energy, though due to the lower power output of solar cells, solar flight is not applicable in any context other than unmanned aerial gliders or pseudo-satellites. Such aerial vehicles have enormous wing spans for maximum lift and to allow for as many solar panels as possible to fit onto them. As a result, they can stay aloft in the stratosphere for extended periods, using only sunlight as energy.
When it comes to innovation in the field of solar flight, Airbus has three main goals:
1. Developing advanced photo-voltaic solar panels that are lighter, more flexible, and capable of capturing more energy per m2 of surface
2. Converting captured solar energy into electrical energy to power an electric-propulsion system and other onboard equipment
3. Harnessing solar energy into a rechargeable energy storage system, thereby enabling the aircraft to fly at night with unlimited autonomy.
Part 2: Airbus UpNext: Solving the Problems of Tomorrow
Airbus’ future concepts fall under three main categories:
1. Disruptive design, which involves testing new, and often radically different configurations of aerial vehicle design in order to improve performance and deliver environmental benefits.
One such example is the Airbus Racer experimental helicopter. It is optimised for a cruise speed of over 400 km/h, 50% faster than a conventional helicopter. It also consumes 15% less fuel. The fundamental difference between the Racer and a conventional helicopter is that it incorporates lateral pusher propellers, mounted on either side of the chassis to generate extra thrust. In addition, box wings serve to generate lift at cruise velocity. This allows the main rotor to be slowed by up to 15% as the craft’s air speed increases and prevents the rotor blades breaking the sound barrier which would reduce performance.
2. Biomimicry is also known as biologically inspired engineering. Many of Airbus’ newest projects take inspiration from natural phenomena in order to achieve better results. One such example is ‘Sharklets’, which are vertical wing-tip extensions that resemble a shark’s dorsal fin. They significantly reduce the size of the wingtip vortex, thus reducing induced drag. Currently, all members of the A320neo family of aircraft are fitted with sharklets as a standard. Another biomimicry project is ‘AlbatrossONE’, a remote-controlled demonstrator aircraft used to put semi-aerolastic hinged wing tips to the test. These freely flapping wing tips are capable of reacting and flexing to wind gusts, and as a result, have the potential to alleviate wing loads and avoid tip stall and drag.
3. Materials engineering allows the construction of more durable, lightweight, and cost-effective aircraft. When developing new materials, Airbus prioritises sustainability, multi-functionality, and digitalisation possibilities.
Airbus UpNext is the innovation branch of Airbus. It focuses on demonstrating future technologies well beyond what seems feasible today. In doing so, it is actively shaping the future of the aerospace industry. Airbus UpNext’s primary goal is to identify the trends that could disrupt the future of the aerospace industry and evaluate them to demonstrate their potential as a viable product.
Apart from being behind some of the technologies and projects already mentioned in this article, Airbus UpNext is working on a project called “fello’fly”, which aims to demonstrate the technical, operational and commercial viability of two aircraft flying close together during long-haul flights. This collaborative activity is expected to make a noteworthy impact on commercial aircraft’s environmental performance, including fuel savings of 5-10% per trip. The main challenge associated with this particular project is finding a solution (in the form of pilot assistance functions) to ensure that aircraft remain safely positioned at a steady altitude in order to effectively make use of wake-energy retrieval (the same technique which migrating geese use when they fly in formation).
Announcement: I have been fortunate enough to interview the CEO of Airbus UpNext, Dr Sandra Bour Schaeffer, as part of my Talking Engineering series. She has more than 20 years of experience working at Airbus, and in the interview, we talk about the lessons she has learnt, the technologies she has overseen, as well as her vision for the future. If you enjoyed this article, which I wrote as a precursor to the interview, then you will most definitely enjoy the interview itself. Stay tuned for Talking Engineering 6 with the CEO of Airbus UpNext – to be published very shortly!