While most eyes are trained on the daily flying display, a central theme of the Singapore Airshow this year has surrounded sustainability. Chee Hong Tat, Singapore's minister for transport and second minister for finance, sent that message on the eve of the Singapore Airshow with the announcement of a national blueprint to reduce emissions from the country's aviation sector by 20 percent over 2019 levels by 2030.
The attention on sustainability marks a significant change from what would have occurred as late as 2019, remarked Robert Boyd, APAC regional sustainability lead for Boeing, during a briefing at the air show. The industry is committed to net zero by 2050 and most airframers now target 2030 to have their aircraft capable of running on 100 percent sustainable aviation fuel (SAF).
The companies might differ in their approaches, but they agree that meeting those goals is imperative.
Boyd pointed to the oft-recited statistic that aviation accounts for 2 percent of the total global production of CO2 emissions. However, he cautioned that the percentage likely will creep up as airline operations continue to expand.
“The 2 percent is a well-rehearsed figure. We know that the key with the 2 percent is that number expands,” Boyd said. “If we don't decarbonize at the same rate as the general economy, it's as simple as that. So that's why the imperative is for aviation to have a clear plan to decarbonize over the next 26 years by 2050.”
From a business aviation standpoint, the industry segment increasingly has become a target of environmental activism. “We take sustainability very seriously because the current trend right now is to blame business jets about CO2,” said Carlos Brana, executive v-p for civil aircraft for Dassault Aviation.
For Boeing, the strategy toward net zero depends on the emissions produced. The longer the route, the more emissions aircraft emit. Medium- and long-haul flights collectively account for 73 percent of industry CO2 emissions. Commuter operations, involving nine to 50 seats and an hour of flight, accounts for just 1 percent of the industry total.
A Multifaceted Approach
While right now many companies cite SAF as the most realistic mode of emissions reduction, as time goes by, other modes will become more common depending on operations. For instance, by 2025, Boeing sees possibilities for battery-electric or hydrogen fuel cell powertrains along with SAF for the smallest commuter aircraft. By 2040, hydrogen could play a role in medium-haul aircraft. However, the outlook for long-haul aircraft in the same timeframe most likely relies on SAF, making the goals toward 100 percent by 2030 all the more important.
Boyd conceded that SAF availability is a key constraint, as only a single percent of the industry's total need is accessible today. He further acknowledged that the fuel quantity will not be ready by 2030, despite the stated goal of the airframers.
However, he noted that an aircraft delivered in 2029 could operate for decades.
Most OEMs use SAF in multiple ways. Brana noted Dassault uses a blend of up to 50 percent SAF in its demo flights, test flights, and ferry flights.
Some manufacturers have been conducting trials and demonstrations of 100 percent SAF. For example, Gulfstream in November completed the first trans-Atlantic flight using 100 percent SAF in a G600. But implementing the use of pure SAF on a full-time basis will present difficulties, Brana said. Concerns still exist surrounding the long-term use of SAF for wearing on engine seals, he explained.
Dassault is among numerous entities researching how to make a compatible SAF. “I would say we have never been so close,” Brana said, noting there are several options that the industry is exploring. “One of them, which is very promising, is e-fuel based on a combination of hydrogen and carbon. This is not yet implemented but it’s going to come.”
He pointed to Rolls-Royce tests of 100 percent SAF. “It’s working fine…So those fuels are coming,” he noted.
Although it accounts for a central strategy, SAF represents only one route to net zero by 2050, added Boyd. He cited four paths, namely fleet renewal, operational efficiencies, renewable energy such as SAF, and advanced technology.
Fleet renewal provides an instant benefit in the neighborhood of 15 to 22 percent efficiency with new aircraft supplanting older models. Operational efficiencies, such as improved air traffic management, might be the most overlooked but can provide significant advantages, Boyd said. But many impressive tools exist to achieve them, he added.
Dassault introduced one such tool, a FalconWays flight-planning application designed to help pilots determine the most flight-efficient routes. The app pulls together various data—including aircraft performance, weight, and weather—to determine the optimum flight route to save on fuel burn.
“The software can compute trajectories from point A to point B using the lowest amount of fuel,” Brana said, noting factors such as wind that weigh into the algorithms. The app further looks at operational capabilities such as noise and considers weather.
“So, we are saving fuel, but not diverting the airplane toward the airports when the weather does not permit you to land,” he said.
For an example of advanced technologies, he pointed to research such as Boeing's joint research project with NASA to transform an MD-90 single-aisle airliner into an experimental X-plane designated X-66A to test a transonic truss-braced wing configuration for efficiencies.
OEMs Explore Options
On the eve of the airshow, Bombardier further updated activities surrounding its blended-wing-body EcoJet phase 2 technology demonstrator, which has generated substantial data in its quest to reduce emissions of a Global 6000-sized business jet by 50 percent.
Bombardier believes the aerodynamic efficiencies of the EcoJet could account for around 20 percent of the desired fuel savings, with new propulsion technologies accounting for a similar saving. The remaining 10 percent of the 50 percent goal would come from other technological advances, such as advanced weight-saving techniques and materials.
Boyd reiterated that all four paths are crucial for the industry goals. “To get from where we are today in terms of emissions created to zero by 2050, it requires each and every one,” Boyd stressed.
Market-based measures such as Europe’s CORSIA (carbon offsetting and reduction scheme for international aviation) initiative underscores the point.
But SAF “will be the solution for the long haul.” He envisions a place for hydrogen, but it must be developed in a green way. Most hydrogen available today is not produced using sustainable energy sources. The same goes for electric, he added, noting that the grid needs to become greener.
Boyd expressed encouragement by the progress the industry has made, however. A vast amount of research is ongoing across the industry, and regulators have started to take notice, embracing the industry goals. Policy is important to unlock SAF, he stressed, and the more it is available the less it will cost.
Proving the technological capabilities is critical to such support, and companies continue to demonstrate it at events such as the Singapore Airshow. Airbus’s A350-1000 is conducting SAF-powered flight demonstrations at the show, participating in the daily aerial displays.
Boyd outlined an array of initiatives across research, engineering, and design efforts across Boeing's various segments to improve sustainability in all areas.
In addition to promoting SAF, Airbus announced during the air show that it has signed a memorandum of understanding with the Singapore Economic Development Board (EDB) to facilitate the establishment of a Sustainable Aviation Hub with a specific focus on technology, research, and innovation. The hub will bring together aerospace professionals, researchers, and other innovators to collaborate on research and development of a sustainable aviation ecosystem.
The air show provides a platform for companies to promote the multitude of efforts related to sustainability.
In announcing the blueprint, Chee said the goal for Singapore involves a balanced approach “so that future generations can continue to enjoy the benefits of flying.”