Sustainable aviation initiatives in the spotlight

Airbus will conduct tests of fuel-saving automated formation flight.
Credit: Airbus

As the aviation industry expands its support for initiatives to reduce its environmental impact, more countries, airlines and companies are making investments and working together to find ways to meet carbon neutrality targets.


When Airbus in November 2019 announced it would demonstrate energy-saving automated formation flight in 2020 using two A350s, and Boeing subsequently revealed it had flight-tested the concept in 2018 with two 777s, it was a signal that a long-known technique could soon be ready for prime time.

Air-wake surfing for efficiency has a long pedigree of consistent research results that show an aircraft can save fuel by flying within the updraft created by the wingtip vortices shed by another—reclaiming energy left in the atmosphere by the lead aircraft’s lift-induced drag.

So why are operators not already using the technique to improve efficiency? And why is it being looked at now? One reason is the availability of the avionics required to enable automated wake surfing, particularly automatic dependent surveillance-broadcast (ADS-B).

“Why now? ADS-B is now mandatory in the US, so we have the avionics to make this possible,” says Al Sipe, chief engineer for aviation efficiency at Boeing. “Why are we not doing it? The fuel savings are not small. We have the capability. But the regulations say don’t do it. So the next step is getting the regulations changed.”

With the benefits firmly established, Boeing’s test in 2018 with its 777F ecoDemonstrator flying behind another FedEx 777F and Airbus’ fello’fly demonstration this year are developing systems and procedures airlines can use to safely and robustly take advantage of wake surfing.

Attention is shifting to the next steps: developing the safety case and taking it to regulators to get the rules changed; agreeing on the procedures between aircraft, operators and air traffic control that will enable wake surfing; and developing the business case for implementation.


House Transportation Subcommittee on Aviation chairman Rick Larsen (D-Washington) introduced legislation that would require the US Department of Transportation (DOT) to study, track and assess the sector’s efforts toward curbing greenhouse gas emissions.

The bill would require the National Evaluation of Aviation and Aerospace Solutions to Climate Change Act to direct DOT to partner with the National Academies of Sciences, Engineering and Medicine to “study, catalogue and report on technologies, processes, materials or practices” that contribute to the reduction of greenhouse gas emissions in civil aviation.

In conducting the study, DOT and the National Academies would focus on identifying gaps in climate change mitigation efforts across the civil aviation industry and would then make recommendations on how best to address those gaps. After concluding the study, the FAA administrator would share an assessment of the recommendations with congressional committees overseeing civil aviation issues in both chambers.

“This bill will help catalog those efforts, identify barriers to the adoption of mitigation efforts, and serve as a roadmap for the steps the aviation and aerospace sector must take to achieve a 100% clean economy by 2050,” said Larsen, who represents Washington state’s second congressional district, home to Boeing’s production facility in Everett, where the company’s widebody jetliners, including the 777 and 787, are assembled.

The bill was co-sponsored by Aviation Subcommittee vice chair Sharice Davis (D-Kansas) and Rep. Kim Schrier (D-Washington), a member of the New Democrats’ Climate Change Task Force.


Finnair and Finnish oil company Neste will partner to increase the airline’s use of sustainable aviation fuel (SAF) and boost production capacity in Finland. Neste already produces SAF at a pilot plant in Porvoo, Finland, and is expanding its commercial renewable-fuel refinery in Singapore.

“Sustainable aviation fuels are a key part of our long-term plan for carbon neutrality,” Finnair CEO Topi Manner said. “By the end of 2025, we expect to spend some €10 million [$11.3 million] annually on sustainable aviation fuels.”

Finnair spent more than €678 million on fuel in 2019, so its target for SAF use represents less than 1.5% of that total. This reflects both the current lack of SAF production capacity and its high cost—SAF is three to five times as expensive as conventional jet fuel.

In 2019, Neste produced 100,000 metric tons (110,000 tons or 33,000 gal.) of SAF. This is planned to increase to 1 million metric tons in 2022 as a result of a €1.4 billion investment in boosting production of renewable diesel and jet fuel by increasing the capacity of its Singapore plant.

Finnair will encourage passengers to support its use of sustainable fuel by offering tickets that include a SAF option later this year. The airline says it will match the contribution customers make to SAF with its own purchases. 


Boom Supersonic said its XB-1 test program will be fully carbon neutral through the use of sustainable aviation fuels and carbon offsetting. 

XB-1, Boom’s supersonic demonstrator aircraft, is designed to prove inflight the key technologies for safe, efficient and sustainable travel at supersonic speeds, the company said.

“Since Boom’s founding, we’ve been on a mission to make the world dramatically more accessible through supersonic travel,” Boom founder and CEO Blake Scholl said. “With our commitment to a carbon-neutral XB-1 test program, we’re laying the groundwork for a sustainable supersonic future with Overture,” Boom’s supersonic commercial airliner.

Boom said it is ushering in a new supersonic era where environmental considerations are essential throughout the aircraft’s design, testing and flying. 

Boom is nearing completion of its XB-1 demonstrator, history’s first independently developed civil supersonic aircraft. The design, build and test phases of XB-1 are intended to inform the design of Overture, and lessons from XB-1 have already helped optimize Overture, which is expected to enter service at the end of the decade. 


European and Chinese researchers are working together on a project—called the Greener Air Traffic Operations (GreAT)—to reduce aviation’s contribution to climate change, focusing on flight optimization techniques, mitigation policy strategies, sustainable aviation fuels and atmospheric modeling.

The project aims to reduce “gate-to-gate” fuel consumption and emissions by developing and assessing an environment-friendly air traffic operational concept, adaptive airspace and trajectory optimization as well as supporting avionics.

Led by German aerospace center DLR, GreAT involves seven European and six Chinese partners, ranging from KLM to the Civil Aviation Administration of China. The project runs from January 2020 to June 2023 with a budget of €7 million ($7.7 million)—€2.7 million of that is from the European Commission.

The European participants are focusing on optimization strategies for short-haul flights, and the Chinese partners on long haul. Cross-evaluation campaigns between the European partners and in combination with the Chinese participants will validate the reduction in climate impact from the proposed concept.


Air France is adopting new methods to cut its environmental footprint, as part of its stated goal to cut CO2 emissions per passenger-kilometer by 50% by 2030, compared to 2005 levels.

To lighten an aircraft’s weight at takeoff, an “under supply” principle is being implemented, says CEO Anne Rigail. Typically, instead of loading the galley with one meal per person, the catering team will load the number of meals likely to be actually eaten, according to statistics. The same approach is used for drinking water.

Pilots are urged to use iPad applications that optimize the flight for a lower fuel burn. When taxiing, crews use only one engine, or two in the case of the four-engine Airbus A380.

Sustainable fuel, made from salvaged fats, is to be used on flights from San Francisco, starting in June. The location was chosen because of the availability of such fuels, Rigail explains. The blend in the aircraft’s tank will incorporate 10%-50% of biofuel.

Air France spends an annual €3.5 billion ($3.8 billion) on fuel and sustainable fuel is at least twice as expensive as oil-based Jet-A1, Rigail notes.


Swedish airport operator Swedavia aims to equip its 10 airports to handle electric aircraft and place the first commercial electrified route in service by around 2025.

Sweden’s Åre Östersund Airport—a testing venue for electric aircraft—should be ready for the first electric aircraft in autumn 2020. Planning is currently underway for aircraft parking stands, infrastructure for charging aircraft and the necessary power supply, and to ensure the necessary permits.

Swedavia said the investment in electric aviation is “another step in its work to promote the changeover to fossil-free domestic air transport in Sweden by 2030 and fossil-free air transport for all flights originating in the country by 2045. For many years, Swedavia has been carrying out work to increase the use of sustainable biojet fuel.”

Swedavia president and CEO Jonas Abrahamsson said, “Biojet fuel is critical in a short-term perspective for driving the aviation industry’s transformation in the face of climate change. But in the long term, electrification can also play a key role. Swedavia wants to take an active part at an early stage of this development and get an understanding of the conditions needed for electric aviation from an infrastructure perspective.” 

Test flights of electric aircraft and drones will be carried out in the airspace between Åre Östersund and Røros Airport (Norway), in collaboration with a number of partners in Sweden and Norway under the framework for the EU project Green Flyway. The Green Flyway arena is a meteorological and topographical area for tests of electric flights and drones in this part of Sweden and Norway.

“We believe there is good potential for the first commercial electrified route in Sweden within five years. In the longer term, the electrification of routes can be an important addition to today’s scheduled traffic, primarily domestic flights,” Abrahamsson said.


Irish LCC Ryanair is inviting customers to double their voluntary carbon offset contribution from €1 to €2 ($1.09 to $2.18). This increase forms part of Ryanair’s continuing sustainability campaign, which includes an investment worth over $20 billion in new aircraft technology that will carry 4% more passengers, but with 16% lower fuel consumption and 40% lower noise emissions. 

Currently, more than 3% of Ryanair customers are participating in this voluntary carbon offset scheme. According to the airline, 100% of these funds go to supporting Ryanair’s environmental carbon offset projects. Over the last year, this has funded more than €500,000 worth of woodfire stoves in Uganda and over €250,000 toward a reforestation project in the Monchique region of Southern Portugal, which was devastated by forest fires in 2018. 

With increased funds from this growing voluntary contribution scheme, Ryanair said it will aim to provide more funding to more partners in 2020. 


Delta Air Lines plans to spend $1 billion over the next decade to “mitigate” all emissions from its business, investing in a wide range of initiatives to reduce or eliminate carbon emissions throughout its business.

“[We] know there is no single solution. We are digging deep into the issues, examining every corner of our business, engaging experts, building coalitions, fostering partnerships and driving innovation,” Delta CEO Ed Bastian said. “We are on a journey, and though we don’t have all the answers today, we know that our scale, along with investments of time, talent and resources will bring meaningful impact to the planet and ensure the sustainability of our business for decades to come.”

Delta’s plan will not eliminate jet fuel, nor will it rely solely on offsets. It includes reducing fossil-fuel consumption through its fleet modernization—including 80 new aircraft delivered in 2019—more efficient operations, and investments in biofuels.

— Linda Blachly, Sean Broderick,
Thierry Dubois, Ben Goldstein, Kurt Hofmann and Graham Warwick contributed to  this article.


1 Comment
"In 2019, Neste produced 100,000 metric tons (110,000 tons or 33,000 gal.) of SAF." Actually, 110,000 tons (or 220 million pounds) should equal 33 million gallons (assuming 6.7 lbs/gal) of SAF. Unless SAF is 1000 times heavier than kerosene, of course. :-)