AEROSPACE VerticalAerospaceeVTOLs Vertical Aerospace eVTOLs
Vertical dreams are made of these
TIM ROBINSON FRAeS reports on the UK’s leading eVTOL company, Bristol-based Vertical Aerospace, as it gets set to make its dreams of zero-emission urban mobility fly in 2022.
Vertical Aerospace’s 200mph VX4 model. Vertical Aerospace
Only two years ago in January 2020, the debut of a black, boxy-looking mockup of a ‘flying car’ on public display in the UK’s Canary Wharf might have produced sniggers of laughter from some quarters, that this clumsy-looking portacabin was indeed the future of flight.
Yet, just two years later, in February 2022, the same company has received over 1,000 future orders for aerial taxis from major airlines, is set to fly a sleek prototype of a follow-on winged eVTOL this year and, in December, was listed on the NYE stock exchange after securing a $2.2bn SPAC merger. Comprised of industry veterans from the aerospace and automotive sectors, it has assembled a dream team of top-tier aerospace suppliers and is working closely with regulators to ensure that, when aerial taxis do enter service, they will be safe.
The UK company on this steep trajectory is the Bristol-based Vertical Aerospace, which in record time has emerged as one of the world’s leading eVTOL developers – since it was founded in 2016 by Stephen Fitzpatrick – who also founded OVO Energy and was the owner of a F1 racing team.
Vertical is one of over 200 companies worldwide that is now racing to unlock a market for urban air mobility (UAM) that could be worth $30.8bn by 2030. While there are undoubtedly major questions (see ‘The eVTOL bubble’ p14) over the size of the eventual UAM market, the emerging eVTOL sector has attracted not just start-ups with convincing CGI but credible and sober aerospace firms, like Airbus, Bell and Embraer.
Tim Williams Chief Engineer, Vertical Aerospace
The dream of urban air mobility (UAM) is a long one, from fanciful Victorian-era postcards that envisaged aerial taxis of the future being landed on art deco rooftops, to ‘flying cars’ of the 1950s, to jetpacks in the 1960s. Helicopters briefly offered a hope that this could be a mass transit mode but the cost and noise has kept these for the wealthy as niche VIP and corporate transport. The 1990s and early 2000s saw NASA’s SAT (small air transportation) effort and the very light jet (VLJ) craze, which sought to utilise small GA airfields for point-to-point travel, come to naught.
However, in the second decade of the 21st Century, the convergence of advances in electric propulsion, battery power, lightweight composites, sophisticated autopilots, along with the external drivers of grid-locked megacities and the growing green agenda has meant that many believe that the time is now right for zero-emission flight as a brand new mode of aerial transport. Says Vertical Aerospace President Michael Cervenka, writing in the RAF’s Air & Space Power 2021: “These aircraft will be in our skies sooner than people think”.
In its short history since 2016, Vertical has already proved itself to be a swift and agile developer, flying its first unpiloted sub-scale demonstrator, the ducted-fan VA-X1, in 2017. In 2019 it flew its second demonstrator, the VA-X2 Seraph, which was also the vehicle on public display in Canary Wharf in early 2020. Later that year saw the five-seat VX4 unveiled, which has unleashed a staggering number of supplier partnerships and orders over the past 12 months, culminating in a $2.2bn SPAC merger with Broadstone Acquisition Group.
VA4 in the wind tunnel at Filton. Vertical Aerospace
Vertical Aerospace Chief Engineer Tim Williams, an ex-Rolls Royce hand, says that the company’s agility is one of the things that sets it apart – turning CFD into rigs to get data points very quickly. “It’s our ability to turn around rigs just to get that data point really quickly. Can we create a very quick rig with stuff that we’ve got around us? Can we get some data? Can we get another point on that curve so we know which direction we’re going? We are very agile in getting those data points across all the spectrums we’re working on – structural, aerodynamics, control systems, all those sort of things. It’s a very agile company.”
Vertical now has almost 300 people working for it and has drawn from ex-aerospace veterans from companies like Boeing, Rolls-Royce, BAE Systems, Leonardo and Airbus – as well as key hires recruited from the automotive industry – where electrification is also preceeding at pace. “We’re seeing quite a mixture of engineers from different disciplines coming in to help us. It seems to be working very well and it’s adding to creating a really good culture in the company and a good mix of breadth of experience,” says Williams.
As well as experienced aerospace and automotive engineers, the chance to join the fast-growing eVTOL sector is also attracting keen young graduates, says Williams. “We’re finding that there is an awful lot of competition to come and work for Vertical. We opened up four positions on a graduate trainee programme we’re putting together. We have a good 500 applicants for those four positions.”
Last year also saw Vertical poach former X-35B JSF test pilot Justin Paines from rival Joby Aviation to be its Chief Test Pilot. As a military test pilot on the VAAC Harrier, Paines was responsible for helping to develop the new flight control laws and pilot interface that allow F-35B pilots to hover ‘hands-off’ – a feat that was all but impossible in the Harrier. A more suitable test pilot to develop carefree handling for VTOL aircraft would be difficult to find.
Vertical’s VX4 air taxi, revealed in 2020 is a far cry from the company’s previous two flying demonstrators, and shows the design evolution from a wingless ‘flying car’ to a sleek shape with lifting surfaces and V-tail. The four-seat (plus one pilot) vehicle features eight propellers, with the forward four five-bladed propellers on the leading edge of the wing rotating from lift to cruise mode. Meanwhile, the rear four two-bladed propellers, which do not tilt, are only used in VTOL mode and fold away in conventional horizontal flight. The aircraft features a retractable tricycle undercarriage.
Vertical Aerospace
With its electric motors and lithium-ion batteries, the VX4 has a top speed of 202mph, a range of 100+ miles and aims to be 100× quieter than conventional helicopters in both the cruise and hover. This ability to operate in urban areas previously off-limits to helicopters, reduced maintenance, enhanced redundancy and low-cost per passenger mile, is why airlines and operators are now taking serious interest in the VX4 and similar eVTOLs.
While the company has partnered with established suppliers on the electric motors (Rolls-Royce) fly-by-wire system, flight controls, avionics (Honeywell) wings and wiring system (GKN Aerospace) Solvay, (composites) and Microsoft (cloud computing), it is keeping two key technologies, rotors and batteries in-house as propriety technologies.
Explains Williams: “Noise and performance are going to be key parameters that differentiate the different eVTOL companies from each other. From a noise perspective, we’re targeting a significant reduction from the current noise levels of a traditional helicopter. We feel that applying our research into rotors, keeping that in-house, will enable us to develop high-strength, high-integrity, low-noise, high-performance rotors.” He adds: “Similarly for batteries. The position, the location, the way the batteries are packaged into the aircraft has a massive impact on the rest of the aircraft. So we are really working hard on optimising those batteries but also keeping in mind how we might increase battery pack capacity in the future to extend the range and performance of the aircraft. We see big advantages by being in control of those and masters of our own destiny. So that’s why we’re focusing on those two key technologies that we want to keep in-house.”
Another reason for keeping batteries in-house is that thermal management of the batteries will be feeds into turnaround and recharging time at the other end. Williams says that spare power for diversions is already “baked into our battery modelling and our life cycle analysis” but the cooler the batteries can be kept during flight, the quicker the turnaround time. Vertical is aiming for 5-10 minutes turnaround time.” You’re not going to do anybody any favours by tying up one of these vertiports or helipads for a significant amount of time. So we know that’s an absolute key constraint for the operability and availability of these aircraft,” says Williams.
The aircraft will also have reduced training requirements, compared to conventional helicopters, taking its cues from the F-35 FBW system. Two control sticks in the cockpit provide acceleration and direction, while the pilot’s displays will be similar to the latest helicopter glass cockpits. Williams notes the ease of flying: “I’m not a helicopter pilot but I’ve been in a military simulator. I managed to hover for about two seconds before I burnt both engines out and crashed the helicopter. But in our simulator I’ve flown the VX4 across most of London.”
With the aircraft tested in wind tunnels at Filton in 2021and assembled, Vertical aims to fly the VX4 this year, beginning with hovering trials, before testing the conversion mode, then finally conventional horizontal flight. The company aims to finalise design phase, rig and bench testing of the certifiable aircraft in 2022, along with Design Organisation Approval (DOA), leading to EASA and CAA certification and first delivery of the VX4 in 2024.
One major challenge for Vertical is the certification process of an entirely new and novel electric mode of transport – and one that is specifically designed to fly over populated areas. As the long-running two-decade certification saga of the Leonardo AW609 tiltrotor shows, even novel aircraft using kerosene-powered engines will generate extra scrutiny from flight safety authorities. The fallout from the 737 MAX also means that eVTOL developers will need to put in additional effort to convince regulators of the airworthiness and safety of these vehicles.
While Williams admits that “we’re trying to execute a really aggressive demonstration and certification programme,” he stresses that Vertical has done its homework and has engaged early on with regulators. Indeed, he says the VX4 prototype was designed around EASA’s EC eVTOL regulations – with the company also having input into these standards. EASA was also invited to witness Vertical’s early battery safety trials, which saw a 15 metre drop test and flame testing. “We have a really good relationship with EASA,” says Williams.
Vertical is also a founding member of the UK CAA’s newly established eVTOL Safety Leadership Group (eVSLG), an international consortium that also includes rival Joby Aviation, the AAIB, air traffic providers NATS, as well as operators Bristow Helicopters, Flexjet and Virgin Atlantic. This group has as its aim that the development of the highest standards of safety in the nascent eVTOL sector are built in from the start.
With the VX4 now heading for first flight, Vertical has now got a growing list of customers keen to get their hands on this zero-emission VTOL aircraft. Last year saw the company rack up an impressive list of around $4bn in orders from Virgin Atlantic (150), American Airlines (250 + 100 options), airline lessor Avolon (310 + 190 options), as well as offshore operator Bristow (50) and Japan’s Marubeni Corporation (200) – giving a total backlog of 1,350 aircraft. Through lessor Avolon, this also includes Japan Airlines (50 and 50 options) and Brazil’s largest airline, Gol (250).
Meanwhile, in late 2021, Vertical announced it had also partnered with construction company Ferrovial to roll out 25 vertiports across the UK which will support Virgin Atlantic’s eVTOL network.
