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eVTOL at the 10-Year Mark
  • 02 Mar 2023 11:10 AM
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eVTOL at the 10-Year Mark

By Kenneth I. Swartz
Vertiflite, Mar/Apr 2023

The 10th Annual VFS Electric VTOL Symposium brought together more than 500 attendees to assess the current state of the industry.

The Vertical Flight Society’s annual eVTOL Symposium has become the world’s leading technical conference for electric vertical takeoff and landing (eVTOL) industry insiders and innovators. More than 500 people traveled to Mesa, Arizona, on Jan. 24–26 to attend the 10th Annual Electric VTOL Symposium, which was paired this year with the 10th Biennial Autonomous VTOL Technical Meeting.

The eVTOL Symposium rotates between Silicon Valley in California and the Mesa/Phoenix area, which is home to three rotorcraft manufacturers — Boeing, MD Helicopters and Rotor X — as well as major tier 1 systems integrators, such as Honeywell and BAE Systems.

This year’s event featured 18 sessions with 64 invited speakers, plus 27 autonomous VTOL technical paper presenters and plenty of networking opportunities, followed by a tour of Honeywell’s facility at Phoenix Sky Harbor International Airport.

When the first Transformative Vertical Flight (TVF) meeting was held in Arlington, Virginia, in August 2014, the meeting room was filled with 100 wild-eyed engineers, scientists and visionaries captivated by the idea of electric vertical flight, but no one knew if a market would truly develop, or when. Fast forward nine years and the eVTOL dream has now become a multi-billion-dollar enterprise employing thousands of engineers, technologists, programmers and others to develop a wide range of innovative new aircraft designs and systems.

The eVTOL industry grew through the COVID-19 pandemic thanks to new investment, which included a number of aspiring original equipment manufacturers (OEMs) — Archer, Joby, Eve Air Mobility, Lilium and Vertical Aerospace — going public through special purpose acquisition companies (SPACs) mergers, which raised billions of dollars.

These funds have been put to use recruiting top engineering talent and supporting the development, assembly, flight test, certification, production and entry into service (EIS) of numerous innovative aircraft designs.


The annual eVTOL Symposium provides a regular touchpoint to assess where the eVTOL industry has come from, where it is positioned today and where it is heading. Early symposiums focused on the technical viability and efficiency of different aircraft configurations, and later the development of an urban air mobility (UAM) ecosystem. Today, the pathway to eVTOL aircraft certification in the United States, Europe and other countries is the elephant in the room that a few eVTOL developers address in general terms.

The atmosphere of caution was the result of many developers now being publicly traded and, more importantly, the US Federal Aviation Administration (FAA) changing its certification direction in mid-May 2022 when it told industry that winged eVTOL aircraft had to be certified under FAR 21.17(b) for “Special Class Aircraft” in the “powered-lift” category rather than Part 23 for small airplanes with special conditions for vertical flight considerations (see “Commentary: FAA Changes Course on eVTOL Certification,” Vertiflite, July/Aug 2022). This was a 180-degree change in direction from the path the FAA had been leading the industry down for the preceding decade.

The winged eVTOL companies impacted by the rule change are committed to following the new certification path, but the FAA has never certified any aircraft as powered-lift, including the Leonardo AW609 tiltrotor for which the powered-lift category was first defined in 1997.

Lirio Liu, Executive Director of the FAA’s Aircraft Certification Service (AIR-1) delivered one of the government keynote presentations. Her full remarks are posted with this online version of the article, but are summarized here.

“The can-do spirit in the free enterprise system that we have here in the US is fostering a dynamic environment in this world of innovation. And you and your innovative products and business models are the evidence of that,” said Liu in her opening remarks, adding that, “we all share a goal of maintaining US leadership in this aerospace sector.”

This also includes an emphasis on safety and predictability, she said, which is important to investors, innovators and operators alike. Predictability “is key for the VTOL section that we’re working in to maximize the ability to innovate, produce and contribute to the growth and the vitality of the economy.”

Lirio Liu, the head of aircraft certification at the FAA, gave in-depth remarks. (VFS staff photo)

“On this point of predictability, and this audience, I’m sure that the FAA’s approach to Powered-Lift has come to mind. We call it a shift. Many of you call it a U-turn. I get it.”

Explaining the context for the shift, Liu said, “As the FAA looked ahead to grant design and operational certifications of winged-eVTOL vehicles, it became more and more and more apparent that such aircraft may not easily be certified or operated as airplanes under Part 23 going forward — airplanes generally don’t take off vertically or have transition to flight regime.

“So continued pursuit of this approach would encounter too many obstacles for the logical and efficient introduction of the winged eVTOLs in our National Airspace System [NAS] as we saw it. We needed a pathway for applicants to obtain the necessary design and operational approvals for the FAA.”

Liu said, “you cannot look at aircraft certification in isolation… but as you move in to the organization, in the FAA, and within Aviation Safety [AVS, the next level above AIR-1], they’re so intertwined and intermingled, and you cannot take them apart and we see that even more now.” As a result, in May 2022, the FAA announced it was modifying its regulatory approach to certification, “so it would be more applicable for when we get to the operations of those powered-lift aircraft.”

This meant type-certifying powered-lift aircraft under a special-class process, which is already within the FAA framework under 21.17(b). This uses some of the performance-based standards that are contained in Part 23 for small airplanes, as well as including what were previously planned to be “special conditions,” but these will be included in the overall design criteria.

“We made this adjustment to provide a solid foundation on which to regulate this dynamic realm of the industry, and the powered-lift [certification pathway] already exists. And this refined approach is consistent with international standards.”

Since the rule change in May 2022, Liu said the FAA has taken a number of initiatives to streamline rules and solicit industry feedback (see also “Washington Report,” pg. 18). On Nov. 8, the FAA published the proposed airworthiness criteria for Joby’s Model JAS4-1 and on Dec. 20 the FAA published the criteria for Archer’s Midnight.

The Federal Register notice also confirmed that the FAA intends to use specific sections of 12.17(b) to provide an equivalent level of safety to existing standards for this new special class of aircraft. The FAA is now reviewing more than 400 comments made by about 50 commentators.

On Nov. 21, the FAA proposed a rule to update the air carrier definition to add powered-lift operations to the regulations so these aircraft can be used by aircraft operators.

In parallel, “the FAA is conducting an ambitious all-agency effort to develop the essential operating rules for powered-lift. And the FAA is developing a Special Federal Aviation Regulation (SFAR)…that will enable the integration of powered-lift into the NAS by defining the regulations for pilot certification and the operations.

“The SFAR is a temporary regulation by nature…but for this powered-lift SFAR, we will establish our initial regulations for those powered-lift pilots and ops. It will give the global community a chance to gain experience and lessons learned, and the data collected from that will help to serve as the basis for the permanent regulations we expect as well as industry consensus standards we would expect to see.”

VFS Executive Director Mike Hirschberg summarized his 30-minute talk as “partnering for safety.”

The race to eVTOL certification is now underway with four leading companies — Archer, Beta, Joby and Volocopter — announcing EIS dates for their aircraft in 2024 or 2025 under FAA or European Union Aviation Safety Agency (EASA) certification. Meanwhile, EHang is operating under China-specific rules established by the Civil Aviation Administration of China (CAAC) and is expected to get its type certification imminently.

The frontrunners include veterans like Joby, which has been refining its aircraft for more than a decade, and startups like Archer that recruited an experienced team of eVTOL developers who were looking for a challenge and a change.

Sergio Cecutta, Partner, SMG Consulting emphasized that the entry-into-service (EIS) date for an aircraft is when the operator commences its route-proving flights, which can only take place after the OEM receives a type certificate, a production certificate and delivers an aircraft.

This means that the four leading OEMs with EIS dates in 2024 or 2025 must roll out and start flight testing their conforming aircraft in 2023 in order achieve a “best case” 18-to-24-month certification program, he said.

Even when the certification requirements for helicopters under FAR Part 27 or Part 29 are well known, there are many examples of certification programs taking longer than expected. For example, the fly-by-wire Bell 525 Relentless first flew in 2015 and is still awaiting certification, which Bell hopes to achieve this year.

Even when international certification rules are harmonized, there are several examples of one regulator taking a year or more to endorse the type certificate issued by another jurisdiction, which is costly for both manufacturers and customers alike. For example, Transport Canada and EASA took years to endorse the FAA certification of the Robinson R66 Turbine, and Airbus is still awaiting FAA certification of the H160, which was certified by EASA on July 1, 2020.

The harmonization of international eVTOL certification is a future challenge.

Aircraft Orderbook

Many of the eVTOL aircraft developers presenting at the Symposium highlighted new investments, strategic partnerships and aircraft orders. This was a major change in tone from the symposiums prior to the pandemic when the eight announced Uber Elevate partners, for example, were largely focused on fulfilling Uber’s UAM vision.

The transition has been largely driven by other sectors of commercial aviation slowly recognizing that eVTOL, electric short takeoff and landing (eSTOL) and electric conventional takeoff and landing (eCTOL) aircraft can complement their traditional business models — most of which were disrupted during the pandemic. And there is growing awareness of the importance of sustainable aviation in North America, which has lagged behind Europe.

United Airlines, with regional partner Mesa Airlines, has partnered with Archer for eVTOL aircraft, Heart Aerospace for eCTOL regional aircraft and ZeroAvia to retrofit its CRJ550 regional jets with hydrogen-electric propulsion. Archer’s first United route will link Newark Liberty International Airport (EWR) and the Downtown Manhattan Heliport.

Delta Air Lines has invested $60M into a commercial and operational partnership with Joby that will include a “home-to-airport” eVTOL service for passengers, initially in New York and Los Angeles.

American Airlines placed a conditional order for 100 Vertical Aerospace VX4 in 2021 and prepaid for 50 aircraft in 2022. The company has also invested in ZeroAvia and may acquire up to ZA2000-RJ powertrains to retrofit its CRJ900 regional jets.

Other airlines placing eVTOL aircraft orders include Global Crossing Airlines, Republic Airways and SkyWest Airlines in the US; Air Greenland, Iberojet, ITA Airways and Virgin Atlantic in Europe; All Nippon Airways, Ascent, Aviair, Japan Airlines and Sydney Seaplanes in Asia; Azul and GOL in Latin America; Falcon Aviation Services in the Middle East; and Fahari Aviation in Africa.

FedEx has teamed with Elroy Air to test middle-mile logistics with the Elroy Air Chaparral hybrid eVTOL in 2023, UPS has 10 firm orders for the Beta Technologies Alia-250 eVTOL aircraft, and DHL has ordered the fixed-wing world Eviation Alice eCTOL aircraft.

VFS livestreamed the event due to capacity limits at the venue. Dr. Mike Leahy delved deep into DARPA’s autonomous and VTOL initiatives, including the upcoming High-Speed VTOL program. (VFS screen capture)

The Bristow Group, one of the world’s largest helicopter operators, is hedging its bets with orders placed for the Beta Alia-250, Elroy Chaparral, Overair Butterfly, Vertical VX4 and Eve’s unnamed eVTOL; Bristow also has an option to purchase the Lilium Jet and orders for the Electra eSTOL aircraft.

It is expected that defense orders for eVTOL aircraft will also follow for many companies currently engaged in agencies such as AFWERX, which expects to field its first eVTOL aircraft in FY2024, but no such orders have been publicly announced.

The customers will gain access to disruptive, new vertical flight aircraft that will increase connectivity and help their companies achieve sustainable aviation goals. And the orders and deposits will provide aircraft developers with a source of cash flow once programs milestones are reached and deliveries begin, as well as strategic insights from customers who operate some of the largest fleets of passenger and cargo aircraft and commercial helicopters in the world.

Defense Capabilities

This year’s Symposium had more defense presentations than previous years thanks to the combined eVTOL and autonomous VTOL themes. The presentations included those by the Defense Research Projects Agency (DARPA), US Army and US Air Force’s AFWERX unit, plus several companies with contracts through AFWERX’s Agility Prime program.

Of course, Russia’s renewed invasion of Ukraine on Feb. 24, 2022, has highlighted new uses for VTOL drones in modern warfare, as well as the urgent need for the US and its NATO and global allies to strengthen their militaries.

The presentation by Dr. Michael Leahy, Director of the DARPA’s Tactical Technology Office (TTO) provided some interesting perspectives on VTOL and autonomy from the Pentagon’s disruptive innovation agency.

Leahy said that the office picks projects that only “require one consecutive miracle” and if they are running on schedule, then “we’re not pushing hard enough.”

VTOL projects in the past decade include the VTOL X-Plane; the Tactical Exploited Reconnaissance Node (TERN) joint project with the US Navy’s Office of Naval Research, which resulted in a Northrop Grumman tailsitter flying wing VTOL design; and the 7,000-lb (3.2-t) Lockheed-Martin/Piasecki Aerial Reconfigurable Embedded System (ARES) uncrewed VTOL that featured twin ducted fans powered by two Honeywell HTS900 turboshafts.

Recent studies include the Silent Marauder Quiet VTOL and the Electric Little Bird, an electric version of the uncrewed Boeing A/MH-6 helicopter, which first flew remotely in 2006.

When it comes to autonomy, DARPA has supported the Aircrew Labor In-Cockpit Automation System (ALIAS), which resulted in the first uncrewed flight of a Sikorsky UH-60 Black Hawk at the US Army installation at Fort Campbell, Kentucky, on Feb. 5, 2022. The Black Hawk was retrofitted with Sikorsky’s MATRIX autonomy technologies that form the core of ALIAS.

Leahy sees autonomy as more than a system that moves joysticks in a cockpit. Autonomy, explained Leahy, involves the use of fly-by-wire technology that makes it possible to fly a helicopter with one or two pilots or take the pilot out of the cockpit entirely.

New VTOL projects include the AdvaNced airCraft infrastructure-Less Launch and RecoverY X-Plane (ANCILLARY) and the High-Speed VTOL (HSVTOL) program. ANCILLARY builds on the work of TERN and is an uncrewed VTOL designed to operate using a laptop of the deck of a ship in Sea State 3 or 4 and deliver a 60-lb (27-kg) payload. The HSVTOL could become an X-Plane sized to transport a squad of troops.

Lt. Col. Olin Walters, US Army Program Manager for Tactical Unmanned Aircraft Systems (TUAS), provided an Army perspective on the uncrewed aircraft systems (UAS) programs underway and the growing requirements for command and control systems.

Highlighting a future challenge, he said the Army currently has about 10,000 UAS platforms supporting all echelons of the Army, but “what happens when there are 10 or 20 million air vehicles?”

The Army classifies its UAS platforms by maximum takeoff weight, segmented as Soldier UAS weighing 1–55 lb (0.5–25 kg), Tactical UAS at 56–1,320 lb (25–600 kg) and Endurance UAS above 1,320 lb (600 kg).

A transformation is underway with the Army developing a small VTOL UAS (under 55 lb) for Special Support and Reconnaissance (SSR) that can perch and stare, carry advanced payloads and have assured position, navigation and timing (APNT) capability.

Today, the Tactical UAS portfolio is dominated by the Shadow V2 and Shadow V2 Block III, but the Army is developing a new Future Tactical UAS (FTUAS) with VTOL and expeditionary capabilities, and outfitted with advanced sensors, modern datalinks and advanced teaming/autonomous behaviors.

The Army wants to eliminate the need for runways, launchers, landing and arresting systems, and a lot of support vehicles; the goal is a UAS that has a smaller footprint, can be transported in a Boeing CH-47 Chinook, has a faster set-up time and has a 54-nm (100-km) line-of-sight datalink range. The Army expects to start doing flight demonstration tests of FTUAS this fiscal year, towards a program of record in fiscal year 2025.


Since the launch of the AFWERX Agility Prime program in April 2020, the Air Force has signed contracts with a large number of eVTOL aircraft and systems developers and has conducted numerous field tests. For example, the first Air Force remotely operated eVTOL flight took place in December 2021 with the Kittyhawk Heaviside, and the first Air Force crewed flight was made in the Beta Alia-250 in March 2022.

In July, Agility Prime is planning a “2-ship Joby Beddown” at Edwards Air Force Base in California and plans to achieve a “baseline operational capability in August” to “leverage initial fielding” in 2024. The Air Force hopes to fly eVTOL aircraft at several joint exercises in 2023.

Lt. Col. “Wasp” Tekell highlighted the Air Force’s Agility Prime program. (VFS photo by Warren Liebmann)

Early in the program, Agility Prime took a four-step multi-attributable trade space Exploration (MATE) approach to identify potential applications for three weight classes of eVTOL aircraft (which they called “Orbs”), explained Lt. Col. John “Wasp” Tekell, US Air Force, the Agility Prime Lead.

The research engaged 10 different USAF organizations and conducted 39 interviews, which resulted in the identification of 66 different use cases and value propositions. The analysis then looked at the desired benefits and relative costs for each of the 66 scenarios. The benefits assessed included coverage range, time to identity, time to deliver, time to rescue, etc. The cost study considered lifecycle costs, maintenance personnel, fuel used, shipping volume, etc.

The cost/benefit analysis then modeled eVTOL and legacy aircraft performance in 840 scenarios that includes legacy aircraft like the HC-130J or HH-60W operating alone, legacy aircraft like the HH-60W operating with eVTOL aircraft, and eVTOL aircraft operating alone.

Specific examples of a large-scale eVTOL deployment by the US Air Force have been lacking until now, but Tekell provided an interesting example of where Agility Prime may be heading.

One of the Secretary of the Air Force’s seven operational imperatives is “resilient basing,” which is designed to reduce US reliance on a handful of forward air bases in the Western Pacific and Europe that could be seen as an easy target opportunity and perceived vulnerability. The development of a resilient forward basing for current and planned tactical aircraft is embodied in the Agile Combat Employment (ACE) concept.

Danielle McLean, CEO of HYSKY Society, led the annual Hydrogen Panel with Liz Collins (National Renewable Energy Lab), John Piasecki (Piasecki Aircraft) and Alex Ivanenko (ZeroAviation). (VFS photo by Warren Liebmann)

The Air Force notes, “ACE shifts operations from centralized physical infrastructures to a network of smaller, dispersed locations that can complicate adversary planning and provide more options for joint force commanders.”

“By leveraging initial fielding in 2024, Agility Prime could provide an affordable, agile, resilient and scalable air mobility network to accelerate the establishment of an ACE basing posture and could help support sustainment of the ACE force in conflict in 2027. Autonomous ORBs enable sustainable [operations and support] and manpower reduction compared to legacy vehicles. For small part, short-range deliveries, there are potentially massive impacts at a fleet scale,” said highlighted remarks on Tekell’s “Resilient Basing” slide.

Rotor X

A number of companies made their first appearances at the eVTOL Symposium, which helped broaden the discussion regarding technologies and markets.

Don Shaw, CEO of Advanced Tactics, Inc. and President of Rotor X Aircraft Manufacturing Co. in Mesa, was one of the first-time speakers in the military session. After serving with the US Marine Corps and working as a spacecraft design engineer and mechanical systems engineer, Shaw started developing a three-to-four passenger vehicle that could be transported in a V-22 Osprey and could fly short distance over roads made impassable by improvised explosive devices (IEDs).

The initial concept used a parafoil and propeller, but he switched to a multi-rotor concept in 2004 and eventually got US congressional earmark funding to build the Black Knight Transformer. This resulted in a drivable multicopter with eight 110-hp engines driving 7-ft (2.1-m) propellers attached by arms to a robust and inexpensive airframe with automotive suspension and doors on all sides.

This was the beginning of Advanced Tactics, Inc.’s work with military rotorcraft and drones. This took on a new dimension two years ago when Shaw bought the assets of kit-helicopter maker RotorWay including the factory location, designs and assets (see “Industry Briefs,” Vertiflite, March/April 2021).

McLean (center) also chaired the annual Workforce Panel with Dr. Maryam Khoshlahjeh (Archer), Matthew Land (Eve), Mike Hirschberg (VFS) and Sharon Rossmark (Women and Drones). (VFS photo by Warren Liebmann)

Now, Shaw is leveraging Rotor X’s experience and production facilities to develop a portfolio of conventional and electric VTOL aircraft. The commercial products in development include the single-seat Dragon personal air vehicle (PAV) eVTOL, which is a multicopter the company plans to sell as an $88,000 kit.

The company also plans to sell a kit for the e600 Phoenix all-electric helicopter, which is based on the recently upgraded A600 Phoenix two-seat helicopter that sells for $125,000 as a kit. Rotor X and its predecessor RotorWay produced over 2,500 kit helicopters since the mid-1960s, and the company expects to sell the eVTOL and e600 to a known customer base.

Shaw’s companies are working on several military rotorcraft for AFWERX, the US Army and the US Marine Corps’ Unmanned Logistics Systems-Air (ULS-A) requirements for small and large rotorcraft capable of moving payloads of 60 lb (27 kg), 350 lb (160 km) and 2,000 lb (900 kg) from a Military Sealift Command or Maritime Prepositioning Force (MPF) surface craft to a material distribution site on shore.

This includes a medium-size ULS-A that can fit in the box of a pickup truck when the rotors and landing gear are stowed; Shaw’s four-rotor ULS-A candidate has a maximum takeoff weight of 7,600 lb (3,450 kg) and can carry a maximum payload of 3,600 lb (1,630 kg) of passengers, cargo and fuel.

Development of the prototype four-rotor aircraft is now underway and funded in part by an AFWERX Phase II Small Business Technology Transfer (STTR) grant. The aircraft utilizes four A600 Phoenix rotor systems and engines mounted on booms that can be folded for easy stowing. The pilot-optional aircraft has a rear ramp, seating for a pilot and 12 troops and a range of 300 miles (555 km) — or an endurance of 12 hours uncrewed.

A smaller autonomous VTOL aircraft, known as the Heavylift Multimission Hybrid Multicopter (HMHM), features storable rotors, booms and landing gear. Finally, the uncrewed Rotor X Avenger eVTOL is being developed as a strike and close air support that can carry various weapons.

The cost of the Rotor X autonomous and eVTOL aircraft is expected to be significantly less than an equivalent turbine-powered helicopter.

Autonomous Cargo

Talyn Air is developing the world’s first multistage eVTOL aircraft that “delivers fixed-wing performance with VTOL flexibility.” The company founders worked for SpaceX where multi-stage launch systems were the norm.

To date, the company has received $4.4M from the US Air Force, US Navy and Agility Prime to develop VTOL vehicles to lift and deploy a variety of fixed-wing assets for the Air Force, allowing “any ship to become an aircraft carrier and any field to become an Air Force base,” said Jordan Thompson, Director of Business Development for Talyn Air.

Production of its 35-ft (10.7-m) wingspan VTOL prototype is expected to be completed in 2023, with numerous flights conducted in the California desert with subscale models, including multiple separation demonstrations and autonomous close formation flight to prove the docking technology. Other testing has occurred on a full-scale electric propulsion system, development of in-house autopilot and battery systems.

For the commercial cargo market, the company is focused on solving the problems of the middle-market logistics with a civil battery-electric VTOL aircraft that has a fixed modular cargo pod, 500-lb (225-lb) payload, 50-mile (80-km) range and competitive economics.

A year ago, Elroy Air CEO Dave Merrill unveiled its new Chaparral autonomous hybrid electric VTOL aircraft at the Hiller Aviation Museum as part of the Society’s 9th Annual eVTOL Symposium. The aircraft is equipped with a modular cargo pod and a robotic system to pick up and deposit the cargo pods, with ultrawideband beacons used to accurately locate a pod. Elroy envisions the aircraft being used for middle-mile logistics and operated in a hub-and-spoke manner from hubs with refueling, routine inspection, maintenance and storage facilities.

In addition to trials planned with FedEx and an order from Bristow, Elroy Air has an order from helicopter lessor LCI for up to 40 Chaparrals. The company is actively working with Agility Prime on a self-storage capability so the Chaparral can be rapidly deployed in and out of a Lockheed C-130 Hercules by incorporating a wing rotation and tail fold, which will also allow the uncrewed eVTOL to be transported in a standard 40-ft (12.2-m) Conex container or a utility trailer. Aircraft production is currently taking place outside of San Francisco, California, where the company hosted a visit from the Chief of Staff of the Air Force, Gen. C.Q. Brown, Jr.

An iron bird and thrust stand are being used to validate the motor, propeller and hybrid-electric powerplant.

Flight testing will take place at Byron Airport in California where a quick deployment flight pad made from Supa-Trac material has been installed and a hangar leased that can accommodate several aircraft. The next step in the program is full-power simulated flight testing of the planned hardware/ software configuration.

Recent additions to the team include Alex Blake as Chief of Staff, who was most recently VP of Engineering at Kittyhawk, and Zach Lovering as VP Engineering. Lovering previously led the Airbus Acubed Vahana tiltwing eVTOL team and was at Zee Aero before that.

Martin Peryea, CEO of Jaunt Air Mobility, now a subsidiary of AIRO Group, explained how the company is developing both passenger and cargo versions of its Journey eVTOL. The cargo version will have a larger-volume cabin and Jaunt is working with VerdeGo Aero on the development of a hybrid-electric propulsion system. VerdeGo’s first-generation propulsion system was paired with a Continental diesel engine, but the company recently opted for a German diesel engine that can use Jet-A fuel to power its second-generation hybrid-electric system.

Clark Dutterer, CTO and VP of Business Development at SURVICE Engineering, also spoke about its electric VTOL UAS development efforts with the US military. The company has been partnered with UK-based Malloy Aeronautics since 2015, and has optimized, outfitted and tested the TRV-150 platform the US Navy and Marine Corps customers with the intent to meet the requirements of the future Tactical Resupply Unmanned Aircraft System (TRUAS) program. The TRV-80 can carry a 50-lb (23-kg) payload, the TRV-150 up to 150 lb (68 kg) and the TRV-400 up to 400 lb (180 kg). SURVICE is also a sponsor and host of the annual VFS Design-Build-Vertical Flight Student Challenge (see www.vtol.org/fly).


In the Electric VTOL Leaders plenary session, Adam Goldstein, CEO of Archer Aviation, explained that the dream of building an eVTOL company had started back at his previous company Vettery in New York City, where he learned the ropes about building and scaling teams, raising capital and recruiting.

He then explained that another important step in the creation of Archer was when he came to the 6th Annual VFS eVTOL Symposium in Mesa in January 2019, where he took the Society’s first eVTOL Design Short Course.

“I remember watching Dr. James Wang give his presentation … and he walked through Project Zero, one of the early eVTOL concepts and I went up to him afterwards and was very excited and said, that was very exciting. I want to learn from all you did, and the mistakes you made and how we can try to go back and do it better,” he said. “It really started to set the foundation for what Archer became, so I’m very thankful to VFS and this program that got us here.”

He added that a lot of the success the company has had to date has little to do with the aircraft itself and more to do with the strategy, which from the beginning “just focused on how do we build a vehicle that has the lowest amount of risk, that could also be economically viable. I think that was a totally different approach that sort of helped set the industry on a different course.”

The Electric VTOL Leaders session featured executives from eVTOL companies: Dr. Eric Allison (Joby), Tyler Painter (Wisk), Rob Scholl (eAviation), Dr. Valerie Manning (Overair) and Adam Goldstein (Archer), with Mike Hirschberg (VFS). (VFS photo by Warren Liebmann)

Goldstein said that the industry is really starting to focus on conforming aircraft. “That’s the big goal for Archer in 2023.” Archer wants to certify its aircraft in 2024, and Goldstein believes the FAA wants to help the company achieve this goal.

“As far as next steps, we need to figure out how to manufacture these aircraft at scale,” he said. “We need to build a network to connect these vehicles to make them useful [so] people can start to adopt them on an everyday basis. And there is a big supply chain that needs to get built out.”

He said that Archer will continue to operate with a smaller scale and nimble team, but it has two strategic partners, Stellantis and United, “that are writing big checks and giving us tons of access to resources.”

On Jan. 4, Stellantis announced it will work with Archer to stand up Archer’s recently announced manufacturing facility in Covington, Georgia, at which the two companies plan to begin manufacturing the Midnight eVTOL aircraft in 2024.


While Joby has led the development of the eVTOL industry for more than a decade, the company’s Head of Product, Dr. Eric Allison — previously head of Uber Elevate — delivered a presentation that hasn’t been heard much since the start of the COVID-19 pandemic just after the 7th Annual eVTOL Symposium in 2020.

Allison spoke of the increasing return of workers to their offices and the return of traffic congestion to the highways surrounding the San Francisco Bay Area that sees commuters wasting 360 million hours a year, contributing to a total of 4.6 billion lost hours in the top 15 US cities.

Uber’s business shifted from ridesharing mobility to food delivery during the first year of the pandemic; it sold Elevate to Joby in December 2020 at the same time as it increased its investment in the Bonny Doon, California-based eVTOL company.

Allison said there is a large market awaiting Joby’s eVTOL aircraft, which will be used to provide multimodal journeys from optimally placed skyports. The S4 can fly 150 miles (240 km) on a single charge at speeds up to 200 mph (320 km/h). It will be “flown by a professional pilot — we are not waiting for autonomy.” This is coming from an industry pioneer who has “probably seen more eVTOLs fly than just about anyone else,” said Allison, referring to his work with Zee Aero, Kitty Hawk, Uber Elevate (with 10 partners) and now Joby.

The vertically integrated company is developing a suite of apps for riders, pilots, heliports and operations that will be used to integrate first mile and last mile ground vehicle ridesharing with an eVTOL flight on Joby’s own on-demand Part 135 airline using the Joby or Uber app. This work builds on the lessons learned just prior to the pandemic when Uber Copter operated a chartered fleet of Bell 430s that flew more than a thousand multimodal trips between Manhattan and JFK International Airport.

Joby believes that the certification of an eVTOL aircraft — encompassing fly-by-wire, highly redundant distributed electric propulsion and unified flight controls — will enable cost-effective UAM operations, with the business opportunities expanding when improved batteries and hydrogen-electric powertrains are introduced. The company is a direct investor in the latter following its acquisition of H2FLY of Stuttgart, Germany, in 2021.


Development of the Overair Butterfly eVTOL tiltrotor is progressing well, including testing of the aircraft’s large-diameter electric tilting rotors incorporating Optimum Speed Propulsion (OSP) and low disk loading, said Dr. Valerie Manning, the company’s Chief Commercial Officer.

The four rotors use variable blade pitch and RPM control to keep the blades at the most efficient operating point during each stage of flight. In 2021–2022, full scale rotor testing in propeller mode was conducted on a static rig and mounted to the top of a truck at a desert test site.

Robert Bassey gave an overview of the FAA’s plans and progress on vertiport infrastructure. (VFS photo by Warren Liebmann)

In-house production has begun on the XP-1 prototype, which is scheduled to make its first flight in 2023. The OA-1 certifiable aircraft design is expected to fly in a few years, followed by its OA-1B design optimized for high-rate manufacturing.

The work is backed by Overair’s strategic partner, Hanwha, which is Korea’s seventh-largest business conglomerate — and largest aerospace and defense manufacturer — and an active technology contributor to the program.

A new facility has been established at the Southern California Logistics Airport in Victorville, California, for flight operations with a test facility and aircraft storage.

Textron eAviation

In March 2021, Textron announced the formation of a new eAviation business led by long-time senior executive Rob Scholl to develop electric aircraft, leveraging the commercial and defense capabilities of its Beech, Cessna and Bell product lines.

In September 2021, Textron unveiled its totally new “Nexus” eVTOL concept, featuring four tilting rotors and two lift propellers. This was followed in April 2022 by Textron’s purchase of electric-aircraft pioneer Pipistrel, which has factories in Ajdovščina, Slovenia, and Gorizia, Italy, that have produced more than 2,000 aircraft since 1989.

Scholl explained that Wichita, Kansas-based eAviation’s goal is to develop a family of sustainable aircraft.

The current product line includes the two-seat Pipistrel Alpha trainer available with a Rotax 912 UL or an electric motor, the two-seat Velis Electro and the Surveyor, which can be piloted, optionally piloted or flown as a UAS.

Future products include the Pipistrel Panthera hybrid-electric light aircraft to be certified under EASA CS-23 for light aircraft, the Nuuva V300 autonomous eVTOL cargo aircraft powered by a hybrid-electric Rotax powerplant driving eight electric motors, and the Nexus, which was transferred from Bell to the eAviation group.

Scholl expects the 3,750-lb (1,700-kg) Nuuva V300 to make its first flight this year and the prototype four-passenger Nexus to make its first flight in the next couple of years and enter service at the end of the decade. The tiltrotor will have a cruise speed of 120 kt (222 km/h), a range of 100 nm (185 km) and a maximum gross takeoff weight of 8,000 lb (3.6 t).


The founders of Dufour Aerospace in Switzerland entered the eVTOL industry in an unusual way — by building and flying Aero1 (previously stylized as “aEro1”), the world’s first electric-powered aerobatic aircraft, which is still used as a company testbed.

As the founders looked for a configuration that would meet their efficiency targets, they discovered the Canadair CL-84 tiltwing, which was developed in the 1960s in Montreal and underwent extensive flight testing in Canada and the United States. One attraction was that the wing was always in positive airflow: “and as soon as you tilt the wing you can reduce power … and this has significant implications for your propulsion system and also means you need less energy overall for the full transition corridor,” said Dufour CTO Jasmine Kent.

Kent said the aerodynamic efficiency of early tiltwing aircraft like the CL-84 and the LTV XC-142 was undermined by their mechanical complexity, “and that was their Achilles’ heel.”

Pre-empting any audience questions about whether a tiltwing has a single point of failure, Kent highlighted that all modern airliners have a trimmable horizontal stabilizer “and we have exactly the same mechanism with a jack screw with a multiload path damage-tolerant hinge.”

Dr. James Wang taught his fifth annual eVTOL Design Short Course on the Monday before the conference. (VFS photo by Warren Liebmann)

For the past few years, Dufour has been developing the Aero2, which is a subscale, uncrewed tiltwing eVTOL demonstrator with four propellers for critical cargo transport. It has an electric powertrain with a hybrid range-extender that utilizes a two-stoke gasoline engine with a generator.

Kent said it’s designed to nominally carry a 88-lb (40-kg) payload for 250 miles (400 km), “but of course since it’s a hybrid you can trade off [less payload for more] fuel for range so it can go over 1,000 km [620 miles] in a long-range configuration.”

The aircraft is autonomous with an uploaded flight plan “but will initially require some supervision and potentially interventions, but over time we will increase its autonomous capabilities,” said Kent.

Dufour has built three generations of prototypes and completed thousands of flights over the full envelope, including demonstrating full transition, over a five-year period with a small team of 40 people.

In November 2022, Dufour secured its first sale of the Aero2 with a firm contract for 40 UAS from Spright, the drone division of the air ambulance operator Air Methods, with an option for an additional 100 aircraft.

Kent told Vertiflite that one of the missions Spright is considering is using the Aero2 to transport patient samples and large tissue specimens to labs to enable quicker diagnoses and more responsive patient care.

The contract included “down payments, which is something rare in the eVTOL industry,” said Kent. During the Symposium, Dufour announced its Series B financing led by private jet charter group Vista Global, which is the parent of VistaJet, Air Hamburg and Jet Edge.

Dufour hopes to secure EASA certification of the Aero2 under its UAS rules by the end of 2024, with first deliveries in 2025.

Sales of the Aero2 will help support the development of the 6,200-lb (2.8-t) Aero3; the piloted tiltwing aircraft has a similar configuration and a turbine-electric range extender. The Aero3 is being developed for aeromedical transport with requires a large cabin with up to eight seats and a greater payload capacity. Medical transport is a high-value, high-margin business with available infrastructure, since most hospitals today have heliports, with the approaches, departures and the airspace integration well defined, explained Kent. “All we have to do is meet the requirements of helicopter operations today and we can slot into this infrastructure.”

An additional reason for targeting aeromedical missions is public acceptance. “If you are trying to introduce a new aircraft, it’s good to have a really clear value that it is delivering,” said Kent.

Dufour expects the Aero3 to be twice as fast as a helicopter with significantly less cost to the operator; it is also targeting some of the ground ambulance market.


Israeli eVTOL developer AIR is developing a two-seat, fixed-wing eVTOL that uses four pairs of lifting propellers for vertical and forward thrust.

Chief Technology Officer Chen Rosen founded the company in 2018 as Polarity Mobility with the idea of developing a simple eVTOL aircraft that could be flown by private pilots. Subscale and full-scale aircraft were used to validate the design and the flight control software.

The company changed its name to AIR EV after CEO Rani Plant and COO Netanel Goldberg joined the company and began refining the design for the general aviation market.

On Friday, Honeywell Aerospace treated conference attendees to tour of its Flight Test Operations at Phoenix Sky Harbor International Airport. (VFS staff photo)

The prototype made its first hover on June 21, 2022, at Megiddo Airport in northern Israel and made its first transition flight in December 2022 at Teyman Airport near Be’er Sheva in southern Israel.

Rosen spent his time at the eVTOL Symposium talking about the potential market for the AIR ONE, not the aircraft or its technology. He said the target market for the aircraft includes private aircraft owners, certified pilots, people who tried to become pilots and those that wanted to be pilots. FAA statistics also show that only a small percentage of the people who take flying lessons actually obtain their pilot’s licence.

AIR believes that the ease of piloting and maintenance and the affordability of the aircraft, plus other elements like space and comfort will stimulate orders, which has proven true.

Rosen also explained that other design features of the aircraft help address the top 10 general aviation accident categories, such as envelope protection, distributed electric propulsion and VTOL performance.

AIR believes the aircraft is designed to inspire pilots and nonpilots. By December 2022, the company had booked more than 260 pre-orders (with $1,000 down) for the $150,000 base price aircraft.

AIR plans to establish a presence in the US to pursue FAA certification under the Light Sport Aircraft (LSA) standard, which is being updated for electric aircraft under the planned Modernization of Special Airworthiness Certificates (MOSAIC) framework, with a notice of proposed rulemaking (NPRM) expected later this year.

To Be Continued

The first 10 years of eVTOL development have seen tremendous progress in development of aircraft configurations, eVTOL technologies, standards, regulations, partnerships and commercialization.

It is clear that 2023 will be a banner year as the FAA and EASA firm up their certification plans, and eVTOL companies prove out their designs, make progress towards certification and begin scaling up for production. Limiting factors will be funding, available talent and the uncertainty of final certification details. The annual Symposium is always an excellent snapshot of the current status and plans of the leading eVTOL developers and the larger ecosystem. Next year’s 11th Annual Electric VTOL Symposium will be held in conjunction with the 6th Decennial VFS Aeromechanics Specialists’ Conference — as part of Transformative Vertical Flight 2024 — on Feb. 6–8, 2024, in Santa Clara, California. Details are posted at www.vtol.org/tvf2024.

About the Author

Ken Swartz is a senior aerospace marketing communications strategist, running Aeromedia Communications in Toronto, Canada. He specializes in aerospace market analysis and corporate communications. He’s worked in the regional airline, commercial helicopter and commercial aircraft manufacturing industries for 30+ years and has reported on vertical flight since 1978. In 2010, he received the Helicopter Association International’s “Communicator of the Year” award.

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