Next generation aviation
_{Challenges and lessons for aerospace}

What is next generation aviation?

While next-gen aviation encompasses various innovations in the industry, electric vertical take-off and landing, (eVTOL) technology stands out in particular. This technology, powered by batteries or fuel cells, drives a distributed set of electric powertrains with tilting propellers, enabling almost silent, cheap and zero-emission vertical flight.

Not only does eVTOL represent a fundamental step towards fully sustainable aviation, it also holds significant potential to disrupt regional ecosystems. If charged with renewable energy, these eVTOL craft will help to alleviate city congestion, and provide faster and cheaper commutes.

This new crop of aircraft is not a replacement for long-distance planes, but rather a whole new mode of air travel, with a range of new use cases. Drones using VTOL techniques are already commonplace for surveillance, inspection and military applications. Larger eVTOLs – some of which may eventually be automated – are already in advanced development and plan to transport passengers or cargo across and between urban areas.

Even as early VTOLs start to find commercial use cases, yet more innovative approaches are being explored. Jetoptera, for example, uses electric compressors to create an air pressure differential within the centre of a ring (picture a Dyson Airblade) which pushes air through at high speeds, generating thrust. It claims its approach could be up to 50% more fuel efficient than a propellor. This is an area rife with innovation.

What is notable is that – being created from scratch in the 21^st Century – these new innovations have sustainable propulsion at their heart, and most are built around intelligent software and digital engineering. They are therefore interesting, both in how they will shape the future of aviation, but also in what they can teach some of the incumbent aerospace companies.

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The challenges of next gen aviation

Getting an entirely new mode of transport off the ground – especially one that may hover above densely packed urban areas – is fraught with engineering challenges.

Take Ascendance Technologies, an innovative future mobility startup, to which Capgemini is a partner. It has developed a new hybrid propulsion system called STERNA, an electric system powered that can be powered by fuel and/or batteries, which is installed in its ATEA VTOL, but has the potential to be installed in any small/medium range flying vehicle. Success with eVTOL requires a variety of challenges to be solved. For example, developing such technology required a completely new electrical architecture and complex thermal management to transform energy into thrust, with new wing and propeller designs to optimize flight physics and reduce noise. And all of this needed to be done within the strict constraints of safety regulations. You can read more about Ascendance Flight Technologies’ work here.

For electric propulsion, battery optimization is perhaps the most pressing challenge. Small flying vehicles require high energy density, high power densities and long-life cycles; and they will eventually need to be manufactured at high-volumes and low costs if they are to have a viable business model. Air taxis will also need fast charging speeds to enable them to be constantly shuttling passengers about – every minute grounded while charging is lost revenue.

Electric drivetrains will need to be optimised for power conversion from the battery to the motor. And the power-to-weight ratio – whilst not the use-case killer that it is for large electric aircraft – must be brought down through efficient design and materials choices, to get the most out of battery power.

Designing for user acceptance is another challenge, and one that may be new to aviation, where planes have historically existed mostly outside of people’s sight and hearing. But filling city skies with flying machines will not be everyone’s cup of tea and eVTOLs may face fierce resistance. Whilst this is partly a communications challenge, such aircraft will need to be designed and engineered to be minimally intrusive. Noise is a particular challenge. Drone propellers are – according to Nasa – one of the most annoying sounds imaginable. Engineering quieter vehicles, especially for takeoff and landing, may be decisive in user acceptance.

And, of course, all this must be done without compromising safety.

A call for the best engineering brains to solve the most difficult challenges

Across this series of articles on sustainable aviation, the emerging theme has been the need for high quality engineering, backed by cutting edge digital tools and the use of software and data, to overcome thorny challenges. Next gen aviation is certainly no exception.

Deploying battery expertise and modeling capability into eVTOL companies will be critical. Batteries have an optimal temperature range, and thermal management is key to their optimization. But this is highly use case dependent – ambient temperatures and heat dispersion are different in the air than on the ground. Experts in thermal management will be needed to understand airborne batteries and – using physics-based models and simulations – design heat transfer systems to optimize performance and ensure safety.

Similarly, digital engineering enables engineers to simulate and analyze the behavior of other key components, including flight handling qualities and operational scaling, in a virtual environment. This allows them to identify design flaws and optimize performance before manufacturing begins. Bespoke software will also need to be written to optimise the whole product in use, from battery management systems (BMS), to flight controls and handling qualities.

Once testing begins, data captured from simulations, and then from onboard sensors, can feed back into an iterative process to further optimize design. This allows engineers to make ever more informed decisions about component design, material selection, and system architecture.

A digital engineering approach, backed by real engineering expertise, can also help rapidly test new concepts. For example, a team at MIT have been investigating using toroidal propellers to reduce noise. The team put together digital models, 3D-printed their prototypes, and collected usage data to iterate design.

As a final point, whilst we are focusing here on sustainable aviation, it is worth noting that there are other challenges facing next gen aviation, from automation, to communications protocols, to air traffic management, to pilot training. Whilst these are not strictly sustainability issues, these will need to be overcome in order to get this sustainable mode of transport in the air. These too will all benefit from digital, data, and software expertise.

A new certification challenge

Once a new aircraft has been created, it must also be certified. Getting certified requires ground testing, simulations, in-flight data acquisition, critical software testing, and detailed data collection and reporting, in order to meet European Union Aviation Safety Agency (EASA)/Federal Aviation Administration (FAA) airworthiness requirements. This is the most expensive and challenging task prior to market entry. It is a particular challenge for a new transport mode with no certification precedent.

Digital technologies can help speed and optimise complex processes, whilst offering a degree of rigor that will help assure regulators, who are themselves still working out this new industry. Opportunities here include automating data capture across tests to speed the process; applying AI to that data to create simulated test scenarios; and using cross-sector data to develop anomaly detection algorithms that can automate critical elements of testing (see here for a deeper dive on eVTOL certification).

A platform for innovation

Next gen aviation is a minefield, but a minefield where lots of companies compete. It remains unclear who will emerge as the winner, but whoever it is will need teams of skilled people with expertise in engineering, digital engineering, software, and certification.

Next gen aviation may seem an obvious business for today’s aerospace companies. They know the world of flight, aerospace engineering, and certification. Aviation companies may also feel more trustworthy than others when it comes to keeping people safe in the air.

But the lessons from Electric vehicles (EVs) also put automakers in a strong position to help manufacture electric aircraft. Stellantis recently agreed a partnership with Archer Aviation, through which it will exclusively manufacture its Midnight eVTOL, as part of a partnership that provides capital, manufacturing capability, and supply chain access. Toyota, Porsche, Hyundai and Daimler, amongst others, all have collaborations with next gen aviation companies (Joby, Eve, Supernal and Volocopter respectively).

Equally, electric transport is increasingly seen as a software-driven industry – since the moving parts in electric vehicles are actually quite simple, and it is the control systems, connectivity and digital optimization where the real value lies. That puts the tech giants in a good place. And of course, former employees of all of the above may decide to build their own businesses, as many already have.

In short, it is a tough and competitive market with lots of risks. Innovators in this field will need to work hard to optimise efficiency and noise levels, keep costs low, and ensure rigorous attention to safety.

However, another interpretation is that next gen aviation will be part of a collaborative transformation which supports the whole industry. We already see hints that people are leaving big aerospace companies to create eVTOL companies with a ‘digital startup’ mentality, doing rapid innovation, then collaborating or being acquired by former employers, who help them with scale and certification.

This collaborative approach not only advances next gen innovation towards commercialisation more quickly, but also brings the much-needed learnings of innovative startups into established companies. That helps create the culture that aerospace companies will need in order to transform more broadly.