The Future of Advanced Air Mobility

Review of Certification Process and Key Supplier Contributions Prompted Vertical's eVTOL Aircraft Program Delay

Multiple factors drove Vertical Aerospace’s decision earlier this month to push back the target date to certify its VX-4 four-passenger eVTOL aircraft to the end of 2026. But according to the UK company’s chief technology officer, Michael Cervenka, diminishing cash reserves wasn’t one of them, even though it is now launching a new round of fundraising to help cover its needs from late 2024 until when it begins series production and initial deliveries to operators.

As of the end of the first quarter on March 31, Vertical had £104 million ($131 million) in its coffers. Contributing to the inevitable start-up operating loss of £23 million, research and development expenses, at £12.6 million, were 55 percent higher than in the same period in 2022, while “administrative” spending of £11.7 million was almost unchanged.

In December 2021, the company went public on the New York Stock Exchange via a merger with a special purpose acquisition company. However, this step came relatively late compared with progress by rivals, and the flotation raised only around $300 million.

Vertical Says Cash Burn Is Stable

“Our cash burn is fairly stable, and our cash [spend] rate is only about a third to a quarter of other [eVTOL developers,” Cervenka told FutureFlight. “Our massive advantage is we’re an OEM and we’re not having to do ridesharing and all the other stuff.”

Unlike rivals such as Joby and Archer, Vertical has a business model that's entirely based on selling the VX4 to operators, such as Virgin Atlantic Airways, American Airlines, and various leasing groups. It is not having to bear the expense of getting approved to have an air operator certificate and establishing all the supporting infrastructure.

The Vertical payroll consists of some 300 people, including 200 or so engineers, which Cervenka said is far fewer than competitors employ. The company is also backed by leading aerospace groups acting as risk-sharing partners covering the cost of some of the contributions to the program. Honeywell, for example, is providing its new Anthem avionics suite, which will also feature on new business aircraft, while Rolls-Royce is developing the electric propulsion system (EPS) and GKN is making the VX4’s wings.

New Suppliers and Leadership Prompt Timeline Review

According to Cervenka, over the past six months or so Vertical has been reviewing the key steps to type certification, which will initially be conducted with the UK Civil Aviation Authority (CAA) and concurrently with EASA. Over this period, the company made several changes to its management team, such as adding chief engineer David King, who formerly held senior program management roles with Leonardo, Bell, and Boeing, and Eduardo Dominguez Puerta, who was previously CEO of Airbus’s urban air mobility division.

“We have brought in additional supply-chain partners and have to understand how we end up with a better-integrated plan,” Cervenka told FutureFlight. “For instance, we were asking Rolls-Royce for equipment before we were ready for it or before we were ready to certify.”

The VX4 team also conducted focused engagement with both the CAA and EASA over the details of the regulatory framework for new eVTOL aircraft and how long the flight test program will need to be. It also reviewed the role of its various prototype aircraft in the certification process.

In September 2022, the first of these started tethered hover flights using ground power rather than onboard propulsion. Only around 15 percent of the parts and equipment for this came from strategic suppliers, with Vertical using interim off-the-shelf hardware from UK suppliers. The second vehicle, which is now being assembled by Leonardo in Italy, will have around 60 percent of its content from strategic suppliers, including the Molicel batteries, with the proportion of certifiable hardware rising to 80 to 90 percent on the third aircraft and the final iteration coming together in the fourth aircraft to be built.

Cervenka explained that the need to have the right batteries available in large volumes has been a key aspect of the timeline rethink. “We need batteries that are being mass produced rather than [in relatively small batches] in a lab, and Molicel has reached the sweet spot with a battery that is both good in terms of energy and also power density, which is especially important for landing,” he said.

Meanwhile, Rolls-Royce has been taking “a very rigorous and robust” approach to maturing the EPS based on a full understanding of the requirements for it, including all aspects of maneuvering the aircraft in tough conditions and with complete safety redundancy. On the first prototype, a lot of work has been done on the inverter so that the Honeywell wiring systems can control the motors.

This aircraft will resume test flights in the next few weeks, with the second prototype expected to join it in the air later this year, followed by what Vertical calls its first “certification aircraft” in 2025. “Using ground power for the first aircraft was the right decision because we could do a lot of running with all our test pilots both indoors and outside,” Cervenka said. “We have done a lot of dynamic modeling with different motors and speeds, including structural load tests and a lot of work on Honeywell’s flight control software and thermal runaway testing with the batteries.”

In March, the company opened the Vertical Energy Center at its headquarters in Bristol and this is now the hub for all battery testing. In the same month, the CAA issued its design organization approval, which is a key requirement to be able to complete the type certification process, for which the UK regulator is adopting EASA’s SC-VTOL means of compliance.

According to Cervenka, prospective customers for the VX4 are comfortable with the delayed path to entry into service for these aircraft. He said that the new round of fundraising could include some more “meaningful” pre-delivery payments from these operators.

Kakao Mobility Agrees To Buy 50 VX4 eVTOLs

On May 22, South Korea’s Kakao Mobility placed a preorder for 50 of the aircraft. The company, which has some 30 million users for its ride-hailing app, will form a joint working group with Vertical to prepare for commercial advanced air mobility services in the Asian country, which appears set to be an early adopter of eVTOL flights.

Vertical may well find it is not alone in having to push back its type certification timeline. Reflecting on what he sees as a sound and well-defined regulatory approach by EASA and the CAA, Cervenka described the process now being navigated by his U.S. rivals aiming for FAA certification in late 2024 or 2025 as “a massive risk.”