While much attention has centered around the new wave of eVTOL aircraft, research continues at a feverish pace across the industry for a range of new (or renewed) concepts from blended wings to supersonic and all-electric in more traditional aircraft forms. Progress was made on all fronts in 2023, with the field of activity growing more crowded.
Many of these projects draw skeptics. However, the question may be not whether they make it to market but whether these concepts will play a role in shaping the future of flying.
“I am intrigued by these emergent developments,” noted Rolland Vincent, president of Rolland Vincent Associates and creator/director of JetNet iQ. “At this stage, it is difficult to distinguish which—if any—are the survivors, and which are ideas that never get beyond the concept stage. The breadth of concepts is encouraging and reflects the variety of technologies that are certain to attract people and capital to the sector.”
Much of this work is centered around advancements toward a more sustainable future. Indeed, many believe this is imperative for the survivability of the industry. As a testament to this effort, Bombardier president and CEO Éric Martel has said that more of its research and development dollars involve sustainability in some fashion than just about any other area.
The Blended Wing
One of Bombardier’s largest projects on this front is its EcoJet. Unveiled during the 2022 edition of EBACE, the EcoJet blended-wing-body (BWB) project aims to reduce aircraft emissions by up to 50 percent through aerodynamic and propulsion improvements.
At the end of that year, an 18-foot-wingspan air vehicle had made its first flight, and the Phase 2 demonstrator had flown 10 times by NBAA-BACE in October. Flying at an undisclosed North American location, the BWB has roughly 16 percent of the wingspan of a Global 6000. Bombardier reported that the demonstrator is generating large amounts of data as it looks at dramatically cutting emissions of a Global 6000-sized business jet.
The EcoJet BWB concept is seen as having enormous promise in turns of fuel saving. It also offers the potential for carrying large volumes of fuel, which may be an important advantage if fuels with lower power densities than jet-A are selected.
The flight demonstrations are expected to run for at least two years and potentially up to four years. At present, Bombardier has no detailed plans concerning the program’s immediate direction or what propulsion concept might be selected for a full-scale BWB business jet.
But Bombardier is not the only manufacturer in this space. In August, the U.S. Air Force had commissioned JetZero to build and fly a full-scale BWB technology demonstrator for possible military and commercial airline applications. The California start-up, which was awarded a $235 million contract from the Department of Defense’s Defense Innovation Unit, is developing the aircraft in partnership with Northrop Grumman and its Scaled Composites subsidiary.
Under the terms of the four-year contract, JetZero is expected to have a technology demonstrator ready to fly in the first quarter of 2027.
According to JetZero, when deployed as a fuel tanker, its BWB aircraft would carry as much fuel as the current KC-46 workhorse over twice the distance. Alternatively, it could take on twice as much fuel load for the KC-46’s current operating radius.
JetZero also has its sights set on the air transport industry’s need to decarbonize. The start-up intends to offer the design as a 200-plus-passenger replacement for Boeing’s 757 and 767 transports, and also the Airbus A330.
Plans call for the company to use Pratt & Whitney’s Geared Turbofan (GTF) engines, with a view to achieving a 50 percent reduction in fuel burn and carbon emissions through a quantum leap in aerodynamics. The company has said that later versions of the BWB design could be integrated with new hydrogen propulsion technology.
These followed the revelation in 2020 that Airbus had tested a BWB demonstrator, the Maveric, with an eye on seeking fuel reduction possibilities.
The Need for Speed
Meanwhile, the demise of Aerion delivered a blow to the supersonic sector, raising questions about whether it was still a viable path. However, NASA and Boom are believers in the possibility, and Hermeus takes this faith one step further into the hypersonic realm.
All made strides in their respective programs. During the Paris Air Show, Boom updated progress on its Mach 1.7, 66- to 80-passenger Overture, naming Aernnova for Overture’s wings, Leonardo for the fuselage and wing box, and Aciturri for the empennage.
More recently, Boom has been prepping for the first flight of its XB-1 “baby Boom” scale demonstrator, which moved to the Mojave Desert in California earlier this year and has undergone extensive ground testing since. These trials, Boom said, include medium-speed taxi test events reaching 90 knots as it preps for the first flight that was anticipated possibly this year.
NASA is planning for supersonic trials with another “X” aircraft, the Mach 1.4 X-59 Quesst demonstrator, which could collect noise data that may pave a path for the return of supersonic flight over land. However, NASA pushed back the first flight until next year as it works through “several technical challenges identified over the course of 2023.”
Built at Lockheed Martin’s Skunk Works facility in Palmdale, California, the X-59 was anticipated to fly this year. “Extra time is needed to fully integrate systems into the aircraft and ensure they work together as expected,” NASA said, adding that it also is working through “intermittent issues” with safety-redundant computers controlling aircraft systems. The aircraft is undergoing integrated testing and, once complete, will proceed to flight readiness review. At that point, the agency expects to release a more specific timeline for the first flight.
On the hypersonic end, Hermeus, like Boom, plans phased tests of using demonstrators. Also like Boom, it plans to build its own engine, and the company has already successfully tested the transition from turbojet to ramjet for the Chimera powerplant that uses a GE J85 modified to reach Mach 4. This will power the remotely-piloted “Quarterhorse” demonstrator that is anticipated to fly next year.
Hermeus is also prepping for the development of the next aircraft, the larger Darkhorse UAV that will roll out later in the decade and will be used to mature technologies. Hermeus anticipates that Darkhorse will eventually drive capabilities such as ISR and strike for Department of Defense and intelligence customers. Hermeus this year accepted an F100 engine from Pratt & Whitney that will be integrated into the enhanced Chimera II turbine-based combined cycle propulsion system for Darkhorse. While also targeting military applications, Hermeus envisions eventually bringing a commercial 4,000-nm, 20-passenger Halcyon to market to airline and business aviation customers.
As for Aerion, once widely considered the frontrunner in the supersonic race, its assets were transferred to the winning bidder (there was no backup bidder) of an auction last year. That bidder, “Boeing Ace Collateral,” took the assets—including the myriad of patents developed over decades of research—for a value of $200,000. This was a credit bid since Boeing, which had been a partner of Aerion’s, was a lender in the liquidation case.
It's Electric
While research into electric flight has become almost ubiquitous with projects underway across the industry, the quest toward larger aircraft still is a holy grail. Textron eAviation’s Pipistrel broke new barriers with the 2020 European approval of its two-seat, all-electric Velis. The company has new hope for a U.S. pathway under the FAA’s modernization of special airworthiness certificates (Mosaic) proposed rulemaking that was released in July and would expand opportunities for light-sport aircraft.
Diamond Aircraft also has an all-electric version of its two-seat eDA40 that flew for the first time this past summer and is anticipated to receive approval in early 20204. Further, Bye Aerospace is eyeing that space with its eFlyer 2, also a two-seat electric aircraft, that has checked off certification milestones as it approaches Part 23 approval. Next up is the four-seat eFlyer 4.
Moving up the ladder, Bye Aerospace is hoping to take on existing turboprop models such as the Beechcraft King Air 260 with its eFlyer 800 electric-powered aircraft, albeit with less than one-third the range. Powered by a pair of Safran's Engineus electric motors, the larger twin will be able to carry seven passengers and two pilots on flights of up to 500 nm at 320 knots.
Another potential competitor could be Eviation's all-electric Alice, which flew for the first time in late 2022. However, Eviation is refining the design for a nine-passenger model that could be a viable commuter option and, as such, had held off on further flight tests. Plans call for a passenger/commuter aircraft that could fly 250 nm on a single charge and reach market by 2027.
Electric projects, including those involving hydrogen, are under research across a spectrum of aviation and engine makers. However, it may be a hybrid project that reaches market initially, given the limitations of battery power. Daher is looking at 2027 for the potential launch of a hybrid aircraft, since battery power currently limits the use of the electric system to less than an hour.
By NBAA-BACE, the company was readying its EcoPulse distributed propulsion technology demonstrator to fly for the first time on electric power, and definition of the aircraft is anticipated next year. The EcoPulse demo aircraft, which uses the Daher TBM 900 as its platform, has been flying with inactive wing-mounted electric thrusters installed since earlier this year. Embraer also has explored a variety of options from eVTOL to all-electric, having flown an electric EMB-203 Ipanema as a testbed.
Some research has revolved around hydrogen projects, and Airbus has been among those at the forefront of this. But companies such as ZeroAvia and Universal Hydrogen have flown converted aircraft on hydrogen power this year.
The Future?
Whether any of those projects reach fruition remains in question. Brian Foley of Brian Foley Associates casts doubt on much of the current crop of aircraft, noting the climate change environment makes supersonic unlikely and pointing to Bombardier’s debt load as an obstacle to commercializing the EcoJet.
He believes the eFlyer has potential but faces stiff competition from Pipistrel, and he noted “a litany of practical concerns” surrounding hydrogen propulsion. A key issue is environmental: “95 percent of hydrogen is produced using fossil fuels, which is analogous to wrapping a paper straw in a plastic wrapper.”
However, Foley acknowledged the U.S. military support for JetZero and believes that it will progress, at least through the early stages.
Vincent also noted challenges surrounding supersonic: “Speed is one of the last great frontiers in aviation, and it is only a matter of time before this becomes a civil aviation reality. Nevertheless, the demise of the Aerion program signaled the enormous capital requirements and challenges of convincing an engine OEM to invest to power what is seen by many as a niche market.”
He added: “My sense is that designs that offer step changes in fuel burn/energy efficiency will be much more likely to shape the market over the next decade or so.”
And it may be that at least concepts in some of these designs find their way into the next generation of aircraft.
—Charles Alcock, David Donald, Chad Trautvetter, Hanneke Weitering, Matt Thurber, and Mark Huber contributed to this article.
The Need for Speed
Meanwhile, the demise of Aerion delivered a blow to the supersonic sector, raising questions about whether it was still a viable path. However, NASA and Boom are believers in the possibility, and Hermeus takes this faith one step further into the hypersonic realm.
All made strides in their respective programs. During the Paris Air Show, Boom updated progress on its Mach 1.7, 66- to 80-passenger Overture, naming Aernnova for Overture’s wings, Leonardo for the fuselage and wing box, and Aciturri for the empennage.
More recently, Boom has been prepping for the first flight of its XB-1 “baby Boom” scale demonstrator, which moved to the Mojave Desert in California earlier this year and has undergone extensive ground testing since. These trials, Boom said, include medium-speed taxi test events reaching 90 knots as it preps for the first flight that was anticipated possibly this year.
NASA is planning for supersonic trials with another “X” aircraft, the Mach 1.4 X-59 Quesst demonstrator, which could collect noise data that may pave a path for the return of supersonic flight over land. However, NASA pushed back the first flight until next year as it works through “several technical challenges identified over the course of 2023.”
Built at Lockheed Martin’s Skunk Works facility in Palmdale, California, the X-59 was anticipated to fly this year. “Extra time is needed to fully integrate systems into the aircraft and ensure they work together as expected,” NASA said, adding that it also is working through “intermittent issues” with safety-redundant computers controlling aircraft systems. The aircraft is undergoing integrated testing and, once complete, will proceed to flight readiness review. At that point, the agency expects to release a more specific timeline for the first flight.
On the hypersonic end, Hermeus, like Boom, plans phased tests of using demonstrators. Also like Boom, it plans to build its own engine, and the company has already successfully tested the transition from turbojet to ramjet for the Chimera powerplant that uses a GE J85 modified to reach Mach 4. This will power the remotely-piloted “Quarterhorse” demonstrator that is anticipated to fly next year.
Hermeus is also prepping for the development of the next aircraft, the larger Darkhorse UAV that will roll out later in the decade and will be used to mature technologies. Hermeus anticipates that Darkhorse will eventually drive capabilities such as ISR and strike for Department of Defense and intelligence customers. Hermeus this year accepted an F100 engine from Pratt & Whitney that will be integrated into the enhanced Chimera II turbine-based combined cycle propulsion system for Darkhorse. While also targeting military applications, Hermeus envisions eventually bringing a commercial 4,000-nm, 20-passenger Halcyon to market to airline and business aviation customers.
As for Aerion, once widely considered the frontrunner in the supersonic race, its assets were transferred to the winning bidder (there was no backup bidder) of an auction last year. That bidder, “Boeing Ace Collateral,” took the assets—including the myriad of patents developed over decades of research—for a value of $200,000. This was a credit bid since Boeing, which had been a partner of Aerion’s, was a lender in the liquidation case.
It's Electric
While research into electric flight has become almost ubiquitous with projects underway across the industry, the quest toward larger aircraft still is a holy grail. Textron Aviation’s Pipistrel broke new barriers with the 2020 European approval of its two-seat, all-electric Velis. The company has new hope for a U.S. pathway under the FAA’s modernization of special airworthiness certificates (Mosaic) proposed rulemaking that was released in July and would expand opportunities for light-sport aircraft.
Diamond Aircraft also has an all-electric version of its two-seat eDA40 that flew for the first time this past summer and is anticipated to receive approval in early 20204. Further, Bye Aerospace is eyeing that space with its eFlyer 2, also a two-seat electric aircraft, that has checked off certification milestones as it approaches Part 23 approval. Next up is the four-seat eFlyer 4.
Moving up the ladder, Bye Aerospace is hoping to take on existing turboprop models such as the Beechcraft King Air 260 with its eFlyer 800 electric-powered aircraft, albeit with less than one-third the range. Powered by a pair of Safran's Engineus electric motors, the larger twin will be able to carry seven passengers and two pilots on flights of up to 500 nm at 320 knots.
Another potential competitor could be Eviation's all-electric Alice, which flew for the first time in late 2022. However, Eviation is refining the design for a nine-passenger model that could be a viable commuter option and, as such, had held off on further flight tests. Plans call for a passenger/commuter aircraft that could fly 250 nm on a single charge and reach market by 2027.
Electric projects, including those involving hydrogen, are under research across a spectrum of aviation and engine makers. However, it may be a hybrid project that reaches market initially, given the limitations of battery power. Daher is looking at 2027 for the potential launch of a hybrid aircraft, since battery power currently limits the use of the electric system to less than an hour.
By NBAA-BACE, the company was readying its EcoPulse distributed propulsion technology demonstrator to fly for the first time on electric power, and definition of the aircraft is anticipated next year. The EcoPulse demo aircraft, which uses the Daher TBM 900 as its platform, has been flying with inactive wing-mounted electric thrusters installed since earlier this year. Embraer also has explored a variety of options from eVTOL to all-electric, having flown an electric EMB-203 Ipanema as a testbed.
Some research has revolved around hydrogen projects, and Airbus has been among those at the forefront of this. But companies such as ZeroAvia and Universal Hydrogen have flown converted aircraft on hydrogen power this year.
The Future?
Whether any of those projects reach fruition remains in question. Brian Foley of Brian Foley Associates casts doubt on much of the current crop of aircraft, noting the climate change environment makes supersonic unlikely and pointing to Bombardier’s debt load as an obstacle to commercializing the EcoJet.
He believes the eFlyer has potential but faces stiff competition from Pipistrel, and he noted “a litany of practical concerns” surrounding hydrogen propulsion. A key issue is environmental: “95 percent of hydrogen is produced using fossil fuels, which is analogous to wrapping a paper straw in a plastic wrapper.”
However, Foley acknowledged the U.S. military support for JetZero and believes that it will progress, at least through the early stages.
Vincent also noted challenges surrounding supersonic: “Speed is one of the last great frontiers in aviation, and it is only a matter of time before this becomes a civil aviation reality. Nevertheless, the demise of the Aerion program signaled the enormous capital requirements and challenges of convincing an engine OEM to invest to power what is seen by many as a niche market.”
He added: “My sense is that designs that offer step changes in fuel burn/energy efficiency will be much more likely to shape the market over the next decade or so.”
And it may be that at least concepts in some of these designs find their way into the next generation of aircraft.
—Charles Alcock, David Donald, Chad Trautvetter, Hanneke Weitering, Matt Thurber, and Mark Huber contributed to this article.