The increasing convergence of fast-emerging advanced air mobility (AAM) and mainstream business aviation is visible this week at EBACE 2023. Developers of eVTOL aircraft and companies contributing technology to these programs can be found on the exhibit floor, and most specifically at the show's Innovation Zone.
Discussions of new propulsion systems and flight automation capability will also feature prominently in the EBACE Sustainability Summit today and tomorrow—with some of these sessions also at the Innovation Zone. The increased presence of AAM pioneers at the world’s second-largest business aviation show seemingly signals serious intent by the industry to broaden the scope of its efforts to reduce its environmental footprint beyond the ongoing push to increase the use of sustainable aviation fuels.
With several frontrunners in the eVTOL race to market promising to have their aircraft in commercial service barely two years from now, 2023 promises to be a critical time for determining how credible these ambitions are. After investors flocked to the AAM sector in 2020 and 2021, the capital flow started to diminish in 2022 and observers are now starting to assess which players might not have sufficiently deep pockets to complete an onerous type certification process that is still somewhat clouded in uncertainty.
The ambitious performance objectives of the dynamic new sector of aviation have motivated many of the mainstream aerospace industry’s largest players to invest in cutting-edge propulsion, flight controls, and aerostructures technology to support programs in the works with new aircraft manufacturers. These companies include Honeywell (Booth D31), Safran, Garmin (Booth D62), Rolls-Royce (Booth X98), Thales, Collins Aerospace (Booth V72), and GKN Aerospace.
Airbus (Booth Z52) is developing its own eVTOL vehicle, the CityAirbus NextGen, drawing on expertise and technology from across the European group. Rival Boeing (Booth A51B) has skin in the game through its majority stake in California-based Wisk Aero, while Textron Aviation (Booth T26) has established its own electric aviation business unit, bolstered by the acquisition last year of Slovenia-based Pipistrel. Daher (Booth W58) has announced plans to develop a hybrid-electric version of its TBM fixed-wing aircraft based on the EcoPulse technology demonstrator it is working on in partnership with Airbus and Safran.
LiliumJet Seeks Business Aviation Role
One of the highest-profile exhibitors in the EBACE Innovation Zone is Lilium, which is working to secure EASA’s approval for its six-passenger eVTOL aircraft in 2025. The German company first needs to complete the construction of a first production-conforming prototype and fly it, which is now anticipated to occur in 2024. Its engineering team has already been flying a technology demonstrator, most recently at the Atlas test site in Spain.
The design features 30 tilting ducted fans in its wing and canard. The all-electric vehicle is expected to have a range of up to 155 mph and a maximum cruise speed of 175 mph.
Lilium (Booth D32) has been taking provisional orders and some of these have come from the business aviation sector. In December, UK-based private aviation management and charter group Volare said it plans to add 20 of the all-electric Lilium Jets to the fleet of its new eVolare division, with options for another 10.
These will be the special four-passenger Pioneer Edition of which Lilium intends to make just 50 examples, offering a customizable cabin and prices ranging from $7 million to $10 million. The manufacturer aims to have all these units sold by the end of 2023 and said that it has started collecting pre-delivery payments from some customers.
Last year, NetJets agreed to add 150 Lilium Jets to its portfolio of business aircraft. Under a memorandum of understanding, NetJets and its affiliates would operate the aircraft, and Berkshire Hathaway sister company FlightSafety International (Booth W72) is expected to provide flight simulators as it competes with rival training group CAE (Booth P98) to provide pilots for the AAM sector.
Luxaviation is another prospective partner for Lilium and it has now formed a division called Sigma Air Mobility. In 2021, the business aviation services group agreed to work with the eVTOL company to develop plans to secure all the necessary operational approvals and to manage pilots as part of a training program under development by Lufthansa Aviation Training.
Other provisional sales commitments for the Lilium Jet have come from Globe Air, Helity, ASL Group, AAP Aviation, iFly, and Bristow. In addition, Saudi Arabian Airlines expects to take 100 of the aircraft, which features 30 ducted fans and electric motors installed through its wing and canard.
As of the end of 2022, Lilium said it had a provisional sales backlog of 603 units, including many from undisclosed customers, and now aims to firm up these agreements into binding contracts this year.
Paul-Franck Bijou, Lilium’s business development v-p, expects business aviation operators to be among the first customers signing binding contracts because, in his view, “they are faster risk-takers.” He and his colleagues are also working with prospective airline customers looking to deploy the Lilium Jet on scheduled regional services, carrying passengers to and from airports and city centers and thus improving connections between major conurbations such as Munich and smaller communities such as Ingolstadt.
Bijou told AIN that the vehicle’s cabin is roomy enough to accommodate six travelers with sufficient personal space for them not to be bumped up against each other. “The cabin is more like that of a business aircraft, and with advanced cockpits the aircraft is halfway between being a helicopter or a private jet,” he commented.
Like many other eVTOL aircraft developers, Lilium is investing considerable effort toward developing the ground infrastructure needed to make the new vehicles’ vertical takeoff and landing capability meaningful. It is partnered with airport groups Ferrovial and Aéroports de Paris, and Bijou indicated that Europe will see the first Lilium Jets in the air in locations such as the south of France, Spain, Greece, and the UK.
“There are currently no specific regulations for [eVTOL] landing sites, but there is also no specific prohibition so we don’t expect to see regulatory impediments,” Bijou stated. “There will need to be discussions with individual air navigation service providers, and operators will need to show that the aircraft won’t disrupt existing traffic.”
Lilium expects to hold entry-into-service conferences with each new operator during 2024 to implement specific operational preparations such as arrangements for aircraft maintenance and pilot training at least 12 months ahead of initial flights. Bijou said the company will need to approve maintenance, repair, and overhaul service providers for the Lilium Jet by the end of next year, while pilots will need to secure new type ratings closer to service entry so that these approvals are current. The manufacturer expects maintenance contracts for the aircraft and its propulsion system (including batteries) to be covered by power-by-the-hour contracts.
According to Bijou, flight crew could be recruited from the business and private aviation sector. Since the services will operate under Part 135 rules, Lilium believes companies will be able to attract younger, less experienced pilots looking to build flight hours.
In the longer term, Lilium is looking at offering a larger, longer-range version of its eVTOL, though this plan hinges on further progress being made with battery technology. But with the prospect of some flights being operated in conventional takeoff and landing mode from airports, the company envisions the prospect of a 19-seater flying on regional feeder routes into major hub airports.
Fractional Ownership for VoltAero’s Hybrid-electric Cassio
Last year at EBACE, French startup VoltAero (Booth A20) got the business aviation sector’s attention when it announced plans to start marketing fractional ownership shares in its five-seat Cassio 330 hybrid-electric aircraft. The company expects the fixed-wing model to be able to achieve a range of about 800 miles and a cruise speed of around 230 mph, with the ability to operate from runways as short as 1,800 feet.
The Cassio 330 is the first of three aircraft that VoltAero is working to bring to market under EASA’s existing CS-23 type certification rules, with the others being the six- and 12-seat Cassio 480 and 600 models. Each model number refers to the propulsion system power rating in kilowatts.
VoltAero is offering five 20 percent shares in each aircraft, based on a projected initial annual utilization of 800 flight hours. This total could rise to 1,000 flight hours per year as operations expand, with owners being able to fly in aircraft across a planned fleet operated by various anticipated European operating partners, with services beginning in France. In 2021, That country's Montpellier-based Airways Aviation agreed to buy 15 Cassio aircraft with the intention of using them for both private charter flights and regional air services.
According to the manufacturer, operators participating in the fractional ownership program will have an exclusive relationship with VoltAero under which it will sign up customers and also provide training, service, and support, maintenance manuals, and financing options. The French company has not yet released pricing for the shares and is partnered with private flight booking platform Kinect Air on the project.
In developing its hybrid-electric technology, VoltAero has already flown more than 10,000 kilometers in its Cassio 1 technology demonstrator with multiple trips around Europe on typical air taxi and charter flight route segments.
Production versions of the Cassio will be powered by three 100-kilowatt EngineUs 100 electric motors and a 370-hp piston engine, collectively driving a five-blade pusher propeller. The Cassio 1 demonstrator has a pair of forward-mounted propellers, each driven by an EngineUs 100 motor, which is produced by French aircraft engine maker Safran. Electric Power Systems is providing the energy storage system.
The Cassio aircraft will use the propulsion system’s electric motors for all-electric power during taxi, takeoff, “primary flight,” and landing. Power from the internal combustion engine can be deployed during cruise phases to extend the range by recharging the batteries during flight.
In November 2022, VoltAero’s plans were boosted by the completion of a €32 million ($32 million) Series B funding round. This was led by strategic investor Tecnologie e Servizi Innovativi (TESI), manufacturer of the prototype for the five-seat Cassio 330 model, which is expected to make its first flight this year. VoltAero says that once type certification is achieved—in 2024, it is hoped—it intends to produce 150 aircraft per year in its new factory at Rochefort Airport in southwest France.
Italy-based TESI specializes in the production and integration of metallic structures and assemblies, as well as mechanical parts. The company said it has experience in aviation manufacturing with clients including Leonardo, Piaggio Aerospace, and Boeing.
Another key program partner is Thales, which is responsible for airborne data collection and computing solutions, including its FlytLink Edge system. This platform uses a compact processor that’s connected to the cloud to enable real-time data collection, processing, and transmission from an aircraft’s onboard cameras and sensors. The companies have already begun validating the technologies on the Cassio 1 prototype.
ARC Aerosystems Advances eVTOLs and eSTOLs
Earlier this year, Samad Aerospace, the UK startup working on the Starling family of eVTOL and eSTOL aircraft, rebooted itself under the name ARC Aerosystems (Booth C25). It has an ambitious plan to bring new models to market: a compound rotorcraft, as well as a pair of autonomous cargo uncrewed air vehicles (UAVs).
ARC stands for "advancing regional connectivity," and founder Seyed Mohseni said the company’s mission has shifted to serving subregional passenger and freight applications, rather than short flights within urban areas.
The key features of the new Linx P9 design are a main rotor that draws electric power only during jump takeoffs and no-roll landings. An electric motor spins the rotor head until there is enough speed to make the rotors turn, at which point the pilot changes the tilt angle of the rotors for takeoff. A pair of pusher propellers and a fixed wing then support horizontal cruise flight. Once the vehicle is airborne, the rotor will be unlocked to act as a wind turbine generating more electrical power.
The concept is based on a 1960s-vintage Canadian gyroplane called the Avian, for which ARC purchased rights to the type certificate. ARC has added the fixed wing to the design and will use a hybrid-electric propulsion system to support a range of up to around 950 kilometers (594 miles).
The cabin is expected to seat nine passengers, and with six plus a pilot on board the range is expected to be just over 500 miles. The Linx P9, which is roughly the size of the Leonardo AW109 helicopter, will operate at altitudes of up to 1,200 feet and have a maximum cruise speed of 187 mph.
Mohseni believes that the Linx’s architecture means that it will not be subject to current requirements for powered rotorcraft and therefore offers a more cost-effective path to market. “It can be certified like a [fixed-wing] general aviation aircraft, and the competitive advantage of our technology is that it has a defined certification path,” he told AIN, explaining that he expects it to receive airworthiness approval under a mix of Part 23 and Part 27 rules.
According to ARC, the jump takeoff approach means that minimal electrical power is expended for the VTOL stage of operations. “Otherwise, we would have to use about half a megawatt of power for takeoff and would need more batteries, resulting in fewer passengers on board and less range,” said Mohseni.
ARC intends to eventually integrate a hydrogen propulsion system with the Linx aircraft. However, initially, the hybrid system will use an as-yet-unspecified turbine engine.
The company’s engineers have been working in stealth mode on the Linx design for 12 months. The team said it has flown a one-third-scale technology demonstrator and is now increasing the size of its team to complete the preliminary design phase of the program.
Its program timeline calls for a full-scale prototype to be ready to fly by 2025, with a production-conforming version debuting in 2026. The company’s aim is to begin deliveries in 2028.
At the same time, ARC said it is advancing plans for a pair of UAVs called the C-600 and the C-150. Both are derivatives of Samad’s earlier Starling aircraft, but with rotors replacing ducted fans used for the earlier designs, which included models such as the eStarling, QStarling, eStarling Cargo, and Starling Jet. The new models will be available with both all-electric and hybrid-electric powertrains, offering ranges of 400 and 100 kilometers and payloads of 150 and 30 kilograms, respectively.
According to Mohseni, ARC has already flown full-scale C-600 and C-150 demonstrators and they recently participated in flight trials in Scotland as part of the UK government-backed Future Flight Challenge.
To date, all this work has been conducted with limited funding of around $10 million. Mohseni said this has been achieved with the help of low-cost partners in Africa and Asia, which he said have been able to complete tasks at around 10 percent of what they would cost via Western companies. The company is now seeking to raise a further £30 million ($37 million) through a Series A funding round, with anticipated backing from the public sector and a mix of strategic and financial investors.
ARC, which is looking to recruit 26 staffers this year, is preparing to build a headquarters and engineering center at Cranfield Airport in England. The company intends what it refers to as the ARC eVTOL House to be the model for future “eVTOL Aviation Village” developments around the world. With funding provided by partners, these developments might include residential areas and a business park.
Ascendance’s Atea Hybrid-electric VTOL Takes Shape
Another French advanced air mobility startup, Ascendance Flight Technologies, is working on a hybrid-electric VTOL dubbed Atea, which it aims to certify by 2025. The company spent more than three years detailing plans for the five-seat, lift-and-cruise model that is expected to deliver a range of 250 miles and speeds of 124 mph.
Digital images released in December 2022 show eight ducted fans for vertical lift, with four in the main wing and four more in a new large canard, in addition to a single horizontal propeller at the top of the tail section and another in the nose of the aircraft. An earlier design, released by the Toulouse-based company in February, had just a pair of ducted fans for vertical lift in the inner-wing section and a single three-bladed propeller in the nose.
According to Ascendance, the additional fans increase the power available during takeoff and landing and add redundancy and improve maneuverability should one or more fans shut down in flight. The company told AIN that it also believes the new design will be easier to certify under EASA's Part 23 special conditions rules.
By moving the main wing toward the rear of the airframe, the Ascendance engineering team has improved access to the four-passenger cabin, which now features large "sky view" windows. The Atea has retractable main and nose landing gear.
“We set up Ascendance Flight Technologies with a very clear vision of what we wanted to achieve—to accelerate the transition towards green aviation thanks to hybrid technology,” said co-founder and CEO Jean-Christophe Lambert. “The design of Atea is the concrete reflection of our values, our experience, and our know-how. The aircraft we are presenting today is the result of huge efforts by our research and development department, tests and trials on four prototypes, and a great deal of thought on costs and the ease of flying such an aircraft.”
In September, the company raised €10 million ($11.7 million) to support the development of the Atea. It expects to be ready to start flight testing a production-conforming prototype this year.
About a year ago, Ascendance reportedly signed letters of intent for 245 aircraft. It said these early commitments have been made by a mix of six helicopter operators and private flight providers spread across Europe, Asia, and the U.S.
Atea is to be powered by Ascendance’s proprietary Sterna hybrid-electric powertrain. The company said Sterna’s modular design and “embedded intelligence” will allow it to support various energy sources, including sustainable aviation fuel and hydrogen.
The aircraft will use electrical power for takeoff and landing, with a turbine engine powering the cruise phase of flight when less power is needed. This approach is mainly motivated by the desire to reduce noise and emissions.
The company’s founders previously worked on Airbus’s now-suspended E-Fan electric light aircraft program. Its board of directors was recently bolstered with the appointment of several senior executives from the aerospace and automotive sectors, including former Safran chairman Jean-Paul Herteman and former Renault executive committee member Jean-Christophe Kugler. On the board, too, is Agnes Plagneux-Bertrand, who was head of the E-Fan program.
Also in the EBACE Innovation Zone is AirCar, which has been working on a two-seat vehicle that it expects to be able to operate at ranges of up to around 50 miles at speeds of about 75 mph. The Turkish startup, which says it has conducted more than 45 flights with a full-scale prototype, aims to have a cargo-carrying version of the aircraft ready to enter service in 2024, followed by a passenger model in 2026.
Switzerland’s SolarStratos (Booth D19) is also at EBACE this week to promote its effort to fly a solar-powered unpressurized aircraft above 80,000 feet. The mission, which is intended to promote the potential for tapping energy from the sun, will involve the pilot wearing a pressure suit during the six-hour flight.