eVTOL Leaders Continue Apace
By Dan Gettinger, Managing Editor
Leading developers of electric vertical takeoff and landing (eVTOL) aircraft have raised financing to support the development, flight testing, certification, manufacturing and commercial entry into service of their innovative aircraft. Reports to investors and financial regulators are becoming more frequent, and they provide more insights regarding the partnerships companies are developing to support their advanced air mobility (AAM) certification programs, industrial supply chains, infrastructure requirements and commercial flight operations. This is a summary of recent news announcements.
On April 7, Archer Aviation revealed that it has partnered with Hexcel Corporation, a Connecticut-based industrial materials company, on manufacturing capabilities. Under the letter of intent, Hexcel will provide Archer with high-performance carbon fiber and resin systems for Archer’s production eVTOL aircraft. In addition to its high-quality manufacturing materials, Archer cited Hexcel’s experience with the US Federal Aviation Administration (FAA) certification requirements as another aspect that attracted it to the company.
Archer announced on April 27 that it had formed a joint eVTOL advisory committee with United Airlines. The committee will provide the Palo Alto-based eVTOL developer guidance on maintenance and operational concepts. It is chaired by Dave Dennison, Archer’s vice president of engineering, and Mauricio Angel, a senior United Airlines executive. United, a longtime backer of Archer, with its regional partner Mesa Airlines, placed a conditional order for up to 200 of Archer’s Maker eVTOL aircraft in February 2021 (see “SPACtacular Financing: Billions Coming for eVTOL,” Vertiflite, March/April 2021).
On April 26, the South Burlington Development Review Board permitted Beta Technologies to build a new electric-aircraft factory at Burlington International Airport (BTV) in Vermont. The board cleared Beta to obtain a zoning permit for its planned 344,000-ft² (32,000-m²) facility after a local regulation on parking had delayed the process. After warning that it could move its operations from Vermont to New York, Beta reached a compromise with the Board that will see it move most of its parking to another location where employees will be shuttled in.
Aviation Week reported on May 16 that Morrisville, North Carolina-based Blue Force Technologies had filed a lawsuit against Beta in May 2021. Blue Force had built the airframes for two Alia-250 prototypes. According to the article, Blue Force’s October 2018 contract gave it first-right-of-refusal to build production airframes; production forecasts increased in 2020 from 60 airframes over the forthcoming decade to 3,000 over a 10-year span. According to Beta, it issued a request for proposals (RFP) in February 2021 and Blue Force did not submit a formal proposal, thus negating this provision. On May 23, Beta’s Alia-250 took off from Burlington’s airport for a seven-day cross-country trip to Arkansas (see “Beta Flies Cross Country,” Vertiflite, July/August 2021).
Eve Air Mobility, the Brazil-based eVTOL developer, successfully completed a special purpose acquisition company (SPAC) transaction, becoming a publicly traded company and raising $377M. After shareholders of the SPAC Zanite Acquisition Corp. approved the transaction on Friday, May 6, Eve shares began trading on the New York Stock Exchange on May 10.
In taking the SPAC route, Eve follows in the footsteps of other leading eVTOL developers such as Joby, Lilium, Archer and Vertical Aerospace. Eve was spun off as an independent company in October 2020, after being launched by Brazilian aerospace firm Embraer in 2017, under its EmbraerX accelerator unit. Eve will continue to rely on Embraer for engineering support, which holds around 90% of Eve shares.
Despite securing conditional orders for more than 1,800 aircraft (valued at more than $5.5B), Eve has yet to show if it has built a large-scale demonstrator aircraft, setting it apart from its competitors. However, on April 20, Eve announced that it had partnered with Thales to help develop the avionics, navigation, communications and other systems for its eVTOL aircraft.
Joby Aviation announced on May 10 that it has completed a series of flight tests to evaluate the acoustic emissions of its S4 Generation 2.0 eVTOL aircraft. Joby and NASA launched the tests in September 2021 at Joby’s facility within Fort Hunter Liggett near Big Sur, California, using Joby’s first preproduction S4 aircraft. The aircraft registered the equivalent of 45.2 dBA from an altitude of 1,640 ft (500 m) at 100 kt airspeed, a sound level that Joby believes will barely be perceptible against the ambient environment of cities. During take-off and landing, Joby registered acoustic levels below 65 dBA at 330 ft (100 m). Joby conducted the tests as part of NASA’s AAM National Campaign.
On May 18, Joby Aviation revealed that it had acquired Avionyx, a company in Costa Rica that specializes in software development and verification solutions for the aerospace industry. The acquisition is designed to support the company’s efforts to obtain FAA type certification. Joby will establish a second flight verification laboratory in San Jose, Costa Rica, to accelerate software verification efforts.
The FAA awarded Joby a Part 135 Air Carrier Certificate (shown), the company said on May 26. The certificate allows Joby to begin commercial air taxi operations using a conventional fixed-wing aircraft, initially the Cirrus SR22. It comes just under a year since Joby applied for the certificate and is the first of three regulatory approvals required to allow Joby to operate its S4 eVTOL aircraft commercially.
“Over the coming months, we will use our Part 135 certificate to exercise the operations and customer technology platforms that will underpin our multi-modal ridesharing service,” said Bonny Simi, head of operations and people at Joby, in a statement.
On June 8, The Air Current revealed that Joby had acquired the German aerospace company H2FLY in April 2021 for an undisclosed sum. H2FLY is developing hydrogen fuel cell propulsion systems for air taxis, business aircraft and regional aircraft. Since 2016, the company has been using its HY4 flight demonstration aircraft to prove the feasibility of its system. In 2021, the company partnered with Deutsche Aircraft to develop a hydrogen-powered Dornier 328, a 40-seat aircraft, by 2025.
On April 19, H2FLY announced that its demonstrator aircraft, the HY4, reached an altitude of 7,230 ft (2,200 m), a record for hydrogen-powered aircraft, according to the company.
The company also said that on April 12 it conducted a 77- mile (125-km) flight between the German cities of Stuttgart and Friedrichshafen, the first such flight between two major airports for a hydrogen-powered aircraft.
Lilium is working on maturing and demonstrating the underlying technology of the Lilium Jet, its planned seven-seat eVTOL aircraft. On May 18, the Munich, Germany-based eVTOL developer announced that the European Patent Office had published 37 of the company’s patent applications, part of a batch of 50 patents Lilium submitted during 2021.
On May 23, Lilium announced that it had partnered with US firm Honeywell and DENSO, a global automotive parts company based in Japan, to co-develop and manufacture the electric motors (“e-motors”) that will power the fans — which the company calls “engines” — on the Lilium Jet. The three companies have worked collaboratively on Lilium’s e-motor for the past two years, the company said in a statement. It marks an expansion of Lilium’s partnership with Honeywell, which is also developing the avionics and flight control systems for the Lilium Jet.
According to Lilium, the e-motor has its rotor and stator in a centrifugal configuration. This lowers the component’s weight, manufacturing costs and susceptibility to foreign object damage. compared to an axial compressor. It also boasts industry-leading power density, Lilium said, with the first prototype e-motors designed to extract over 100 kW of power from a system weighing just over 8.8 lb (4 kg).
Lilium also announced that it had updated its seven-seater aircraft design after completing a preliminary design review at the end of 2021. In its latest configuration (shown), each Lilium Jet will have 30 electric fans — 12 on the canards and 18 on the wings — six fewer than the three dozen initially planned. Lilium increased the diameter of the engines by 10% so it could reduce the number of engines planned on the seven-seater to minimize the total system weight, parts count and complexity, while increasing the duct size and improving the aerodynamic balance and performance, according to a letter to investors published on March 1. Other design changes included adding winglets to the canards and moving the rear wing rearward and upward.
The minimalistic wheels in the previous conceptual design are now large enough to accommodate a short run-on landing. The company noted that cruise power is only one-tenth the power required for hover, so the uprated landing gear provides an additional safety margin for the aircraft in the event that it is forced fly to an alternate landing site after a rejected vertical landing.
Lilium has partnered with three companies on the batteries for the Lilium Jet. On May 27, Lilium said that it will collaborate with Pennsylvania-based Livent to supply the lithium for its batteries. Then, on May 31, Lilium announced that it had selected Zenlabs, a California-based company, to supply the battery cell technology for the Lilium Jet. Tübingen, Germany-based CUSTOMCELLS will manufacture Lilium’s lithium-ion battery cells using Zenlabs’ technology under license. Based on the capabilities of Zenlabs’ high-silicon anode and high-nickel cathode Lithium-Ion pouch cells produced by CUSTOMCELLS performing as expected, “our Lilium Jet would have an estimated ~250 km [155 miles] of physical range,” or an operating range of about 109 miles (175 km) at full payload, excluding reserves, the company stated.
Meanwhile, on May 25, Lilium said that it had selected Aernnova to collaborate on developing the propulsion mounting system for the Lilium Jet. Aernnova, a Spain-based company specializing in composite materials and structures for aircraft, will help Lilium design the flaps on the aircraft (one flap for each set of three electric jets), a critical component that will contain the propulsion and vectoring systems necessary for the transition from vertical to horizontal flight.
Lilium announced on May 31 that it had successfully demonstrated the ability to transition from hovering to horizontal flight at the Atlas test flight test site near Villacarrillo in southern Spain. The achievement occurred during Lilium’s ongoing flight test campaign in Spain involving the company's full-size demonstrator aircraft, the Phoenix 2. “Main wing transition is a huge step forward on our path to launch and it validates our flight dynamics model,” said Lilium founder Matthias Meiner in a statement.
Another demonstrator aircraft, Phoenix 3, is expected to join the flight test program “shortly,” according to Andrew Strachan, Lilium’s chief test pilot, who spoke with eVTOL.com in a May 19 interview. This will replace the original Phoenix demonstrator lost in a ground battery fire in February 2020.
In its June 6 letter to shareholders, Lilium announced that former Airbus executive Klaus Roewe would take over leadership of the company as CEO beginning Aug. 1 (see “Leadership Moves,” pg. XX), succeeding Lilium co-founder and current CEO Daniel Wiegand.
Volocopter has partnered with Microsoft to develop a version of Azure — Microsoft’s cloud-based computing platform — for AAM operations, the German eVTOL developer announced on May 17. The resulting system will provide a digital platform for VoloIQ, Volocopter’s planned operating system for all electric aircraft and drone operations. VoloIQ is expected to manage a host of services, such as passenger booking, network and flight planning, and vehicle data logging and analysis.
In an announcement on June 7 at the UP.Summit in Bentonville, Arkansas (see sidebar), Volocopter revealed that it had conducted the maiden flight of its four-seat, fixed-wing aircraft, the VoloConnect. The flight occurred in early May at Volocopter’s facility in Germany, the company said, and lasted two minutes and 14 seconds, during which the prototype executed a series of maneuvers. The flight was part of a “demanding series” of tests that form part of an ongoing flight test campaign, according to a company press release. The VoloConnect is the third in a series of eVTOL aircraft under development by the company.
In April, Wisk explicitly stated that its “6th generation” aircraft — first mentioned in a VFS webinar in June 2020 — would have four seats. The current 5th generation Cora, which the company has been flying uncrewed since March 2018, is a two-seat demonstrator. It’s as-yet-unnamed and unrevealed four-seater is expected to be the product that it takes to market as an autonomous (pilotless) air taxi. In April, Wisk published a photo of employees sitting in what may be a mockup, though the caption said it’s “the company’s new four-seat eVTOL air taxi”. Another photo (shown) in late May was of the CEO of Air New Zealand Greg Foran and other employees.
In a blog post, the company indicated that the cabin will be not only longer, but wider too: “The larger seat configuration provides more space for passengers and baggage, while allowing us to ensure that we’re creating a service that is accessible for those with disabilities… Higher payloads and cabin volume will better support other applications and use cases long term.”
On June 8, Wisk announced a partnership with the Australian state of Queensland. A Memorandum of Understanding with the Council of Mayors South East Queensland will see the two organizations work to bring the company’s autonomous air taxis to the region. In addition to its presence in New Zealand, Wisk will now have Australia-based personnel.
Wisk’s Asia Pacific Regional Director, Catherine MacGowan, said: “This new partnership is a great starting point for our expansion across Australasia. Our work has the potential to accelerate the introduction of emissions-free aviation, help reduce transport-driven carbon emissions, and realize the benefits of AAM for the Queensland state economy and the wellbeing of its citizens.”