As the quintessential well-spring of technology innovation, aerospace may be the most visible nexus between engineering and the art of the possible. But higher/faster/farther no longer is driving the shape of things to come. Sustainability is in the driver’s seat and will be for the foreseeable future.
Manufacturers’ (and their customers’) focus on accelerating emissions reductions and efficiency improvements are having a profound influence on everything from aerodynamics to propulsion trends. Perhaps the most dramatic illustration is the rapid development of electric aircraft technology. In 2020, the pace of civil aviation’s electrification will increase sharply as scores of companies, building on the progress of the last few years, pursue zero emissions.
Milestones are being set at a feverish pace. In the most recent example, Vancouver, B.C.-based Harbour Air in mid-December became the first scheduled commercial airline to flight-test an all-electric airplane, with the Federal Aviation Administration and Transport Canada Civil Aviation on hand to witness the event. Harbour Air, the largest seaplane airline in North America, expects to certify the de Havilland Beaver by the end of 2021. The Beaver is not the first electric-powered aircraft, but airplanes flown previously have been either all-electric light models or general aviation types modified to hybrid-electric propulsion.
Also proliferating is the number of would-be electric vertical-takeoff-and-landing (eVTOL) concepts, a trend driven largely by the demand for urban air mobility (UAM) solutions.
Among the more notable financial backers are some of the world’s largest car manufacturers. For example, Joby Aviation recently raised a $590-million Series C round of funding, including $394 million from lead investor Toyota Motor Corporation, for the eVTOL air-taxi vehicle it’s developing. Joby is seeking to benefit from Toyota’s manufacturing experience in building the craft, which Joby claims will be “near-silent when flying overhead.”
Germany-based Lilium is among the developers in the technological vanguard. The aircraft is designed to fly at up to 300 kilometers (165 kt) per hour for 300 km (186 miles), faster and farther than most of the other urban air mobility eVTOLs craft in development. It’s intended specifically for metropolitan areas and an intercity market. The company is aiming for certification by 2024 and the start of commercial service by 2024, preceded by trial operations in various cities around the world.
In parallel with the development of the actual technology, expect manufacturers to become more proactive in figuring out the best approach to successfully introduce the concept of VTOLs to cities and the public. If that part of UAM development is mismanaged or public acceptance is taken for granted, the nascent industry could suffer a major setback. Many UAM vehicle builders already are collaborating with city planners and other stakeholders in addressing this delicate challenge.
Bell is even taking a mockup of its Nexus eVTOL directly to the public and inviting their feedback. “We have to demonstrate safety and earn the public’s confidence from the beginning,” said Carey Cannon, chief engineer of technology and innovation at Bell Helicopter.
One aspect of eVTOL development in particular that manufacturers and service providers may want to follow closely is the establishment of operating rules and certification requirements. Along with how the public perceives eVTOL vehicles’ safety—and noise levels—government-mandated rules and regulations have the potential to be a major barrier to enabling urban air mobility.
In 2019, Europe published the first certification rules for this new class of aircraft—in this case, for vehicles seating up to nine passengers. However, much more needs to happen before air taxis can begin flying over cities. For example, FAA’s certification rules must be in harmony with Europe’s. in addition, regulators and industry must establish the standards that eVTOL manufacturers will use to show they comply with all certification requirements.
Current battery technology is still lagging for vertical take-off-and-landing craft larger than the all-electric vehicles that will be in the first wave of designs. This capabilities gap presents an opportunity for established jet engine makers to perfect gas-turbine-based hybrid-electric propulsion concepts, laying the foundation for a longer-term transition to all-electric architectures suitable for larger eVTOL vehicles when improved battery and fuel-cell technology become available. “We intend to develop a versatile product that we can propose to any [eVTOL vehicle] player in the market,” said Jean-Baptiste Jarin, vice president of Safran’s Hybrid-Propulsion System program.
Innovations in jet engine design and production have been the main source of aircraft-efficiency improvements for decades, but double-digit reductions in fuel burn are becoming harder to achieve. As a result, engineers are giving more attention to the airframe to reduce aerodynamic drag. Their goal: ultra-efficient designs of next-generation airliners. These efforts are also aligned with a range of initiatives aimed at developing sustainable production methods.
On a related front, look for more debate about the possibility of the mandated use of sustainable aviation fuels to meet aggressive environmental targets. As much promise as they offer, synthetic aviation fuels are costly. As a result, government incentives encouraging or even mandating their use may be required until they’re being produced in high enough volumes to put downward pressure on their price. Such fuels account for just 0.2 percent of aviation fuel used and are 2.5 to 5 times more expensive than traditional aviation gas.
Across all of this engineering activity—from aviation’s electrification to the design of next-generation airframes—artificial intelligence (AI) thus far has played a relatively small role. Instead, it has been used mainly by maintenance, repair and overhaul providers to see trends and spot anomalies in vast amounts of data downlinked from aircraft and engines.
That’s changing, and fast. AI techniques such as machine learning are being introduced into new areas of aerospace, with the potential to make huge strides in aircraft design and manufacturing. For example, Boeing’s two-year-old AnalytX organization is applying AI to supply chain and manufacturing management, as well as engineering toolsets. Boeing isn’t alone, of course, in exploiting AI’s potential. Airbus, Lockheed Martin and other major aerospace players are experimenting with the art of the possible enabled by AI.
