Story ID: 399Paris
Airbus uses hi-tech to gain zero emissions
By: Cathy Buyck
Caption: Airbus's low-emissions research spans carbon-absorbing algae, synthetic spider silk, and hybrid-electric propulsion.
Word Count: 1036
Airbus chief technology officer Grazia Vittadini was quick on her feet when asked about campaigns like #IStayOnThe Ground; “flygskam” [“flight shame” in Swedish; the feeling of being ashamed to board an aircraft]; and 16-year-old Swedish climate activist Greta Thunberg’s high-profile train journey through Europe to raise awareness of climate change. How are they affecting Airbus? At the OEM’s pre-Le Bourget briefings May 22 in Toulouse, Vittadini quipped that “Greta” is an acronym for “Green Technology Aircraft.” Her dream? To see Thunberg—who refuses to fly—“stepping on a zero-emissions Airbus.”

The Toulouse-based aircraft manufacturer is feeling the pressure of the climate debate, conceded Jean-Brice Dumont, Airbus executive vice president of engineering. “This is not a trend of the year. This is a mega-irreversible global trend.” He described the situation as scissor-like, with continuing growth in global demand for air travel on one hand and “the environmental pressure pushing us down on the other hand. This is the constraint we have to face for the future aircraft” that Airbus will develop and build, according to Dumont. This “new aircraft” will probably not be for tomorrow, he said, but its requirements are well-defined: easy to manufacture, more automated (even autonomous), more connected, and more sustainable in all dimensions—from the design of the materials to the carbon emissions and its environmental footprint. On top of this, it must be safe. “Safety is the mother of all goals,” he stressed.

According to Vittadini, Airbus has a “strong commitment” to environmental sustainability. The company has subscribed to the Air Transport Action Group (ATAG) goal of achieving carbon-neutral growth for the aviation industry as a whole from 2020 onwards and the Flightpath 2050 ambitions—set out by the Advisory Council for Aeronautics Research in Europe (ACARE)—to pare down NOx emissions by 90 percent and CO2 emissions per passenger kilometer by 75 percent and reduce perceived noise from flying aircraft 65 percent. “No single technology will enable us to achieve these ambitious targets,” she said. “The concurrent and coherent development of technologies such as electrical and hybrid propulsion, autonomy, connectivity, artificial intelligence, and advanced materials will enable the exponential growth in a sustainable way.”

Algae Instead of Carbon Fibers

Airbus is researching the use of advanced materials such as algae and synthetic spider silk to produce extremely strong, lightweight, and flexible fibers. These fibers are developed in a laboratory using their own properties and do not need additional fossil fuels during the manufacturing process. Algae, for instance, is used to capture CO2 from the atmosphere and is then used to extract fibers to turn these into a structural material, possibly to replace carbon-fiber. Likewise, Airbus’s patented 3D SurFin process uses a plasma electrolytic polishing process to improve the fatigue properties of 3D-printed parts in a fully sustainable way.

Additive manufacturing (AM) for complex parts makes sense from a business-economic perspective, but in order to apply AM for highly stressed and cyclically loaded components, the as-built surface roughness needs to be reduced, explained Vittadini. “The typical and traditional surface finishing treatments use chromates or other types of hazardous materials. We want to steer clear from these.”

The group will finish this summer flight-testing its Breakthrough Laminar Aircraft Demonstrator in Europe (BLADE) project. The demonstrator aircraft, an A340-300 modified with two slightly different natural-laminar-flow outer wings, started its flight-test campaign two years ago. Conducted under the EU’s Clean Sky joint-undertaking environmental research program, BLADE aims to achieve a 10 percent reduction in drag and up to 5 percent in CO2 emissions. “We are pretty confident, based on what we are seeing, about the industrialization potential of this solution,” she said.

Breakthrough Technologies

While pointing out that “every little bit helps,” she noted that Airbus continues to explore more breakthrough technologies and configurations as part of its quest to moves toward zero-emissions aviation. Ongoing projects include AlbatrossOne, which seeks to emulate the sea bird’s wing design, which enables it to travel hundreds of kilometers through gliding and dynamic soaring—without putting stress on its wing muscles. For efficient gliding flight, the Albatross locks its shoulder, until it needs to flap its wings for propulsion, rapid maneuvers, responding to turbulence, etc.

A small-scale flying demonstrator model was developed by Airbus UK teams, and AlbatrossOne’s initial test flights focused on the stability of the aircraft with the hinged wingtips locked and unlocked. This kind of initiative is important, Dumont noted, “because it shows us how nature can inspire us.”

Other new technology and configurations Airbus is exploring include the Nautilius Boundary Layer Ingestion concept and electric and hybrid-electric propulsion. The latest step in Airbus’s electrification journey is the E-Fan X, a modified BAE Systems Avro RJ100 powered by a hybrid parallel solution because pure electric systems will not be able to meet the payload and range performance of typical short-haul aircraft “any time soon,” according to Vittadini. “Assuming we have batteries 30 times more energy-dense than the currently certified standard, and we are nowhere near that, the A320 could fly with half the payload and one-fifth or one-sixth of its current range. The physics just don’t work,” she said. “Hybrid propulsion is certainly worth exploring.”

Under the project, first announced in 2017, one of the regional jet’s four turbofans will be replaced by a 2-megawatt (mW) Siemens electric motor (adapted by Rolls-Royce), which will have an integrated 2-mW generator powered by a 2-mW battery pack and a 3,000-volt AC electrical distribution system. “We are going for something that has never been attempted and achieved before,” Vittadini boasted.” The timeline of the first flight of the E-Fan X demonstrator, however, has slipped by a year, to 2021, and Siemens last month pulled out of the project.

Airbus has inked a memorandum of understanding with SAS Scandinavian Airlines to jointly research the operational and infrastructure challenges linked to the large-scale operation of hybrid and all-electric aircraft in commercial traffic. The program is set to run from June to the end of 2020 and will cover five work packages focusing on the impact of ground infrastructure and electrical charging on range, resources, time, and availability.