The Safe Landing position on: “electric Vertical Take-Off & Landing” (eVTOL) Aircraft

What are “eVTOL” aircraft?

Electric Vertical Take-Off & Landing (eVTOL) aircraft refers to electrically-powered aircraft that are capable of hovering and taking-off/landing vertically like a helicopter.

There are a range of concepts and aircraft configurations being developed, but they tend to:
• Carry less than 5 passengers
• Be marketed as a form of ‘flying taxi’
• Resemble civilian drones, with numerous propellors or fans
• Be envisioned as a clean and sustainable way of improving travel connectivity – particularly within large cities that are known to be regularly congested with road traffic.

eVTOL aircraft may also be called:
• ‘Advanced Air Mobility’ (AAM)
• ‘Urban Air Mobility’ (UAM)
• ‘Regional Air Mobility’ (RAM)
➢ if used to travel between (rather than within) cities
• ‘Flying Taxis’ or ‘Air Taxis’

There is a plethora of such aircraft being developed currently, with over 1,000 designs being tracked as of April 2024. These aircraft take on a great breadth of different configurations:

They can be divided into the following classifications by their primary propulsion configurations, i.e. the way they produce and direct thrust:

 

What are the Safe Landing positions on eVTOL aircraft?

This is our high-level overview of our positions on eVTOL:

1. eVTOL are cool: we can see why investors and av-geeks are excited! 😎
2. eVTOL could benefit electric aviation: by progressing electric system R&D ⚡
3. eVTOL are inefficient: an energy-intensive mode of public transport 🚎
4. eVTOL are ineffective: unlikely to reduce urban or aviation emissions 👎
5. eVTOL are expensive: vs. bus/coach/train or fixed-wing electric aircraft 💸
6. eVTOL are not the best use of money: we need to prioritise our funding 💰
7. eVTOL are not the best use of time: we need to prioritise our activities ⏰
8. eVTOL are not the best use of talent: we need to prioritise our workforce 👩‍🔧

For a video presentation of these positions, watch the recording of our “Lunch & Learn” on eVTOL aircraft here:

Otherwise, let us step you through these positions one at a time…

eVTOL are cool

We have to admit, these aircraft look like something out of a futuristic sci-fi movie. For instance check out Archer’s “Midnight” aircraft concept which looks like something Batman could easily be seen in:

This is why we understand the hype. We can see why wealthy investors are readily lured into financing these projects, and aerospace engineers are easily sucked into designing the aircraft.

There’s no doubt a desire in many aviation workers’ minds, and desire from aviation-geeks globally, to see these things take flight – we really do get it.

The question is: should we check our biases, and maybe let our heads steer our hearts a bit more on this one?

eVTOL aircraft could benefit electric aviation

The other thing going in eVTOL aircraft’s favour is a genuine potential that developing these aircraft will help the push to pioneer more sustainable technology, transform the way we power aviation and revolutionise the way we fly.

Electrification is the ultimate goal in decarbonisation.

Electrical systems need to be designed, developed, tested, and certified for safe and efficient aviation use:
• Battery systems
• Electric motors
• Electricity transmissions systems
• Electrical Control Units

Currently, eVTOL companies are leading the way in many respects when progressing these technologies…
… However, we should recognise that this leadership this is mostly due to the large amount of funding they are receiving (more on this below).

eVTOLs are fundamentally inefficient

eVTOL aircraft cater to a niche area of air transport: short journeys where flights can take-off & land from small areas e.g. helipads. Basically helicopter journeys today.

The idea is that eVTOL will revolutionise this market through electrification:
• Electric-driven rotors are small, simple and cheap
• Re-charging is also cheaper than burning fuel
• Low noise (due to smaller rotors)
• Low emissions/pollution
… However, this compromises the aircraft design efficiency to meet the energy-intense VTOL requirements:

All of these factors combine to make us conclude that battery-electric flight will always be more efficiently achieved in an electric fixed-wing aircraft configuration that conventionally take-off & land (eCTOL), rather than in a more energy-intensive eVTOL aircraft configuration.

eVTOLs aren’t an effective mass-transit solution

eVTOL evangelists often market these aircraft as a way of solving urban congestion and pollution. Websites and pitch decks from eVTOL producers tend to show congested roads full of a grid-lock of polluting cars, and eVTOL users sailing cleanly overhead in their electrically-powered aircraft.

It’s true that congested urban environments are a problem in many cities: from New York city, to São Paulo, Jakarta, etc. Scenarios where many people are stuck in traffic, by themselves in fossil fuel-powered cars, blocking the roads and polluting the air, are not great. This can be common, and we do need to reduce this.

… However, there are more sensible and economic options for reducing city traffic, congestion, energy-use, and pollution that don’t involve resorting to eVTOL. For instance:
• electrifying ground transport;
• replacing single-occupancy car use with car-sharing, active transport and public transport;
• using buses/coaches//trains, or eCTOL aircraft, for longer journeys e.g. between cities.

Surely these options should be the focus of urban city planners and policy-makers?

eVTOLs won’t decrease urban emissions

The websites of eVTOL producers also show something striking: the sales pitch scenarios for their products often involve relatively short journeys in cities where public transport options are already available.

For instance, Vertical Aerospace (UK) present a trip from London city centre (Battersea), to London Heathrow Airport, a trip possible in 1h on public transport, but apparently 8 mins by eVTOL:

Meanwhile, Archer (US) present a trip from Downtown Manhattan in New York city centre, to Newark Airport, a trip possible in 1h on public transport, but apparently 9 mins by eVTOL:

However, this trip time conveniently excludes numerous other sections of the journey which would clearly add to the overall eVTOL trip time.

The analysis below shows that even while optimistically assuming the processes of boarding and disembarking from an eVTOL aircraft would both only take a few mins each, we should probably add an additional 20-30 mins to the trip time:

This makes a realistic comparison more like 1h vs. 30mins. Are we really in such a rush that we need to expend significantly more energy flying, rather than travelling more efficiently (and therefore more sustainably) on existing public transport?

eVTOLs may increase aviation emissions

We suspect that the limited payload and range capabilities of eVTOL will confine them to very short trips only and they won’t contribute to effective decarbonisation of the most polluting aviation sectors:

As shown in the pictures above, eVTOLs are often depicted enabling more rapid access between urban “vertiports” in the city centre, and major long-haul airports often located at the outskirts of cities.

We desperately need to develop and introduce electric (or other alternative propulsion) aircraft that compete with commercial airline type aircraft, rather than with public transport on the ground:

eVTOLs won’t democratise air travel

A closer look at Archer’s planned Los Angeles (LA) network map, shows the connections to LA’s Van Nuys airport, a popular LA private jet airport for high-income, high-emitting air travellers:

Could it be that this is the real market for these aircraft, rather than a mass-transit option that will democratise air travel, provide low-cost low-emissions journeys, and significantly cut urban emissions? Note: some of us have visited LA, and travelled on its crumbling public transport. We conclude that LA is desperately in need of improving these offerings on the ground as a priority. This is the way to provide effective, accessible inner-city transport at a reasonable cost for low-income individuals, families and communities!

When it comes to cheap electric air travel between cities, it also seems clear that eCTOL aircraft are far more likely to provide this than eVTOL configurations. Not only are they likely to be far cheaper to design, develop, test and certify, but CTOL aircraft should also be cheaper to produce, operate and maintain:

In addition to high-income cities across the US, Europe and Middle East… you also see rapidly “developing” and expanding cities like Sao Paulo, Mumbai, Delhi or Jakarta being touted as prime candidates for eVTOL networks. These are places where there is large income-inequality and badly congested roads – so a clear appeal for wealthy million/billionaires flying over everybody else who are stuck in gridlock.

A note about air taxis from Agency Partners during the Farnborough Air Show suggested to investors that they might succeed “in cities which have a small wealthy population who are fearful of a much larger poor population (Sao Paolo for example, where helicopters are already widely used).” In our opinion, this sounds like air transport for the elite, not a mass transit solution. It doesn’t take an aerospace engineer to see that these aircraft won’t be cheap and affordable for those on low salaries.

eVTOL aren’t the best use of money, time or talent

About $5-6 billion has been put into funding eVTOLs. In effect, eVTOL start-ups have so far raised over twice as much as electric / hydrogen aircraft start-ups and new SAF companies combined:

✅ If most ‘sustainable aviation’ finance is directed towards eVTOL start-ups, then this will provide some benefit towards electric aircraft R&D.

❌ However, assuming that public and private finance isn’t infinite, this means that we are losing focus on other types of aircraft development. This causes issues due to:
⏰ Time: we likely have less than 10 years before we blow our global CO2 budget for 1.5℃ global heating.
👩‍🔬 Talent: we’re always complaining about a lack of ‘Science, Technology, Engineering & Maths’ or ‘STEM’ workers – we need our best engineers working on the most impactful areas of aviation.

We suspect that fixed-wing electric aircraft (which can also benefit from cheap, simple, distributed electric propellers) that are more efficient in cruise – will have greater aviation decarbonisation potential for longer ranges, such as this concept from Elysian:

 

The aviation worker angle

As aviation workers, while eVTOL are undoubtedly cool and make for flashy imagery of a sci-fi future… we’d rather ‘sustainable aviation’ jobs were grown elsewhere.

We’d prefer to see private/public funding and the best aerospace engineering talents directed towards revolutionary fixed-wing aircraft. These will actually compete with fossil fuel powered jet planes and make aviation genuinely more sustainable and more accessible.

Ultimately, sensible investment in sensible technology is more likely to lead to good industrial strategy, creating aviation markets that will provide sustainable careers as well as a sustainable planet.

The positive story

By focusing R&T funding, time, talent and other resources towards the most efficient types of air transport decarbonisation methods, we can:

⏰ Make best use of limited time!

👩‍🔧 Make best use of our aerospace experts!

✈️ Design an air transport system that is more efficient, more equitable, minimises resource use, and maximises aviation worker employment!

🌎 Secure a liveable planet, ensuring a sustainable aviation industry exists in the future!

Get involved!

If you think this is worth fighting for, and maybe you have an opinion one way or the other about our positions outlined above – we’d love to hear from you!

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