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Featured image of Joby air taxi courtesy of NASA.


Vertical Take-Off Air Taxis Are A Solution In Search Of A Problem (Part 1)

There’s a deep disconnect between the purported urban taxi business models and most of the graphics these eVTOL companies use, which hides a yawning chasm of reality.

There are some remarkable valuations in a certain class of electric aircraft right now, electric vertical take-off and landing, or eVTOL. Joby, which has a tilting rotor air taxi, has a market valuation of $5.5 billion. Lilium, with its 34 electric turbofans tilting in unison into forward motion, has a valuation of $2.7 billion. Archer, another tilting rotor air taxi, is valued at $1.4 billion. China’s Ehang, which is test flying an autonomous air taxi with blades you have to step carefully through to get into the cabin, is also valued at $1.4 billion. Blade Air Mobility is just under $700 million, although it’s more a luxury air travel Uber than an eVTOL firm.

That’s about $11 billion that investors have put in the space. Mostly for overgrown quadcopters. What’s up with these valuations of companies that have, for the most part only recently demonstrated working prototypes, no certified aircraft and currently very limited ranges? I’ll explore that question over this 2-part series.

The global helicopter market for all current models including military hardware, commuter choppers, and the like is only $42 billion annually right now, most of that is military, and a lot of the jobs that many of those helicopters do are now being farmed out to unmanned aerial vehicles. The manned rotorcraft market isn’t growing, something which only Statista appears to get, as it projects a decline of 18% in military sales from 2019 to 2029. That’s aligned with both the global diminution of armed conflict, a trend Pinker documents in obsessive detail in The Better Angels of Our Nature, and the rapid rise of UAVs. Other analyses I looked at projected compounded annual growth rates up to 4.1% through the same period. As I pointed out in my recent assessment of the global aviation shift to electric with an interim phase of biofuels, many of the analysts covering aviation don’t appear to understand that the fundamentals of the space and the future have been radically altered.

Now, I’ll admit to many hours on YouTube looking at flight tests for Joby, Lilium, and many others, including perhaps the most perplexing, Jetoptera, which basically mounts Dyson fans in its airframe, requiring that the massive motor that powers them is inside the fuselage taking up space.

I’m fascinated by the freedom to reinvent airframes that this has given airframe designers. I love the 34 ducted fans Lilium uses. I think the Opener Blackfly’s simplicity as a one-person flying machine is marvelous, and I’d love to play with one. Ditto Jetson One, which is literally an open-framed, eight-blade quadcopter you strap yourself into to flit around the sky for a few minutes. I encourage everyone remotely interested in aviation to lose yourself for part of day reveling in the ingenuity and dreaming about these devices.

But that’s the point. It’s almost entirely dreaming.

I’ve been in a reasonable number of rotorcraft, been around them for much of my life, and looked at economics and maintenance requirements for them. I think the first one I was up in was when I was a kid in Moosonee, as a friend of my father’s was a geologist looking for mineral deposits to mine who used one. I grew up on Canadian military airbases where helicopters are almost as common as jeeps. Later, when I was in the Canadian infantry reserves, I was strapped into one facing out and had the fun experience of it banking and looking straight down at tree tops from 100 feet. I flew the Helijet service from Vancouver to Victoria in BC many times while working on a major pandemic management system, mostly when flight conditions didn’t allow the VFR-only float planes to fly. And in Bali I looked down into the blades of a helicopter practicing touch and go on the beach far beneath me as I paraglided the southern ridge (looking down into rotating helicopter blades while floating on fabric and string is not something I would recommend to anyone).

When I was looking at the space of airborne wind energy in the ultimately vain hope of finding anything there, I spent a lot of time looking at rotorcraft operations and maintenance, as many of the proposed and prototyped technologies were in that mode, including Google’s ill-fated Makani. Do you know what I found? That rotorcraft require a lot of maintenance for every hour flown, a lot more than fixed wing aircraft.

These really cool electric rotorcraft are in the same boat. Joby and Archer feature something increasingly common in the field, rotors that tilt like the V-22 Osprey’s to take off and land, and then rotate for horizontal flight.

Marine V-22 Osprey Tilt-Rotor | NASA

Image courtesy NASA

That sucker has killed 42 people with failures and crashes, almost entirely well outside of combat zones. None of them were due to being shot down. At any given time, about half of the US military fleet of Ospreys is grounded as unfit to fly.

Normal rotorcraft typically require four to five hours of maintenance for a single hour of flight, far more than fixed wing planes. Tilt wing rotorcraft have more failure conditions and complexity, so typically require even more maintenance. Electric drivetrains are much simpler than the engines and drivetrains of normal helicopters, but rotorcraft are hard, and transitioning rotorcraft to horizontal flight with lifting surfaces is harder.

The reason for the rotation is the ugly problem with EVTOLs: going up and down takes an awful lot of energy, and flying forward under rotors is really energy intensive. As the saying goes, helicopters beat the air into submission in order to fly. Transitioning to forward flight by tilting the rotors to horizontal allows wings and body lifting surfaces to come into play, allowing much greater range. Joby did a 150-mile test flight recently, for example. The technology does work, and the greater number of much simpler motors and rotors does reduce the risks, but this isn’t a clear win.

It’s not as if these companies don’t know the expense. Lilium puts its 7-passenger plane at $2.5 million with another annual million for maintenance and operations. These are not cheap and cheerful Yellow cabs.

There’s a deep disconnect between the purported urban taxi business models and most of the graphics these companies use, which hides a yawning chasm of reality. The visuals for all of these devices usually show very rich people putting vacation gear in the boot, or taking off from their clifftop vacation aerie. Yet the business models show massive numbers of flights per day to get prices down to reasonable levels and talk mostly about shuttling people around dense urban areas.

In part 2, I’ll explore the business model problems more, and look at the alternative — and much more sensible — business models that companies like Heart Aerospace and Electron Aviation are pursuing,

Featured image of Joby air taxi courtesy of NASA.

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Written By

is a member of the Advisory Boards of electric aviation startup FLIMAX, Chief Strategist at TFIE Strategy and co-founder of distnc technologies. He hosts the Redefining Energy - Tech podcast ( , a part of the award-winning Redefining Energy team. He spends his time projecting scenarios for decarbonization 40-80 years into the future, and assisting executives, Boards and investors to pick wisely today. Whether it's refueling aviation, grid storage, vehicle-to-grid, or hydrogen demand, his work is based on fundamentals of physics, economics and human nature, and informed by the decarbonization requirements and innovations of multiple domains. His leadership positions in North America, Asia and Latin America enhanced his global point of view. He publishes regularly in multiple outlets on innovation, business, technology and policy. He is available for Board, strategy advisor and speaking engagements.


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