Electric flying cars are dirty old helicopters rebranded

The Jetsons are back, and they’re looking green. 

Electric flying taxis were the toast of the Singapore Airshow last week. AirAsia and a unit of Embraer SA announced deals for nearly 200 of the futuristic vehicles, which haven’t made it beyond prototype stage yet. Such eVTOL vehicles — short for electric vertical take off and landing — have seen an explosion of interest in recent years, with $12.8bn (roughly R193,043,200,000) invested in the field since 2010, according to McKinsey & Co.

The promise of this booming sector is that they’re selling something fundamentally different than the original VTOL aircraft: helicopters. Unlike their noisy, fuel-guzzling predecessors — the transport mode of choice for Bond villains and former US president Donald Trump — eVTOLs will quietly buzz a more ethical breed of passenger between office and home, “connecting communities” and linking the city and the suburbs “in one swift, smooth, and emission-free flight”.

It’s a magnificent triumph of marketing over reality. While eVTOLs promise some genuine advances in aviation technology, the investments being made won’t so much bring about that Utopian future as rebrand the dystopian old helicopter industry for a new generation of the super-rich. If the promise of whisper-quiet, affordable, zero-emissions transport sounds too good to be true, that’s because it is.

Take energy efficiency. It’s always been true that aircraft in cruising flight are remarkably efficient relative to cars and trains that use friction to drag themselves laboriously along the ground. The problem is how to get up there.

Climbing and, to a lesser extent, descending have always taken up an outsize share of fuel consumption in aircraft. That’s particularly the case with VTOL vehicles, which can use up a substantial share of their energy just hovering to treetop height. That means the differences between an eVTOL used to travel from one city to another and one used to travel from one suburb to another are overwhelming.

One 2019 study in Nature Communications concluded eVTOLs could be more efficient than electric cars for 100km  journeys, but noted that 85% of car trips are shorter than 35 km — a level at which a conventional fuel-guzzling automobile results in about the same emissions as the flying car.

Occupancy also tends to be a critical assumption. A 2021 study in the Proceedings of the National Academy of Sciences argued that vehicles like the Larry Page-backed Kitty Hawk Heaviside are already more efficient than electric cars — but a crucial aspect of both analyses is the idea that ground-based modes should be judged by the 1.67 occupants who are carried per trip across the entire American vehicle fleet, whereas eVTOLs should be measured at ideal capacity levels.

That’s not a reasonable comparison. If there’s not a full complement of fresh passengers to be picked up each time a flying car touches down, its efficiency per passenger, per kilometre drops drastically. Such “empty leg” flights, where an aircraft goes to its next destination with no passengers at all, make up about two-fifths of trips in existing private jets. Indeed, there’s an entire cottage industry dedicated to finding cheap tickets on them.

It’s a similar picture with sound pollution. By having several small rotors rather than one big one, most eVTOLs promise to be less noisy — “almost 1,000 times quieter” than a helicopter, according to Archer Aviation Inc. While decibels are a useful objective measure of sound pressure, they don’t correspond much to the subjective annoyance factor for noise, which relates to harder to measure qualities such as frequency, duration, repetition, and the way sound reflects from building surfaces in an urban environment. Noise also corresponds a lot to distance, making an eVTOL quieter the higher its cruising altitude. But climb higher and you’re using more fuel again. It’s almost impossible to be energy-efficient and noise-efficient at the same time.

Perhaps this doesn’t matter. For all the excitement around eVTOLs, they’re likely to account for a small portion of overall traffic in the  future, next to the workhorses of buses, trains, cars and low-cost jets in which passengers will be crammed into ever-smaller seats.

The trouble is, they’re a distraction from the real problems the aviation industry needs to be dealing with — most of all, the question of how most of us will travel by the middle of this century without our carbon emissions destroying the atmosphere through which we fly. About three quarters of investments in future aviation technology since 2010 have gone into urban flying taxis and similar technologies, according to McKinsey & Co., with the urgent question of sustainable aviation attracting only cents on the dollar by comparison.

A grimly plausible vision of the future will see billionaires travel from San Francisco to their weekend escapes in Lake Tahoe, blithely ignorant of their true carbon footprints. The city-dwellers over whom they fly will be stuck in endless traffic, which the political system never seems to get round to solving. Once they get home they’ll be constantly buzzed by the sound of passing eVTOLs they could never afford to fly, thanks to the way spurious arguments about decibels managed to loosen long-standing aircraft noise regulations.

Perhaps eVTOLs are the future of mobility. If they are, it’s not something to be proud of. It’s an admission that transport policy — as something designed to move the mass of humanity from place to place, rather than something to serve the interests of an oblivious elite — has comprehensively failed.

For instance, Archer bases its estimates about noise pollution on a 2,000-foot cruising altitude, twice the 1,000-foot estimate used in the Nature Communications study.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

David Fickling is a Bloomberg Opinion columnist covering commodities, as well as industrial and consumer companies. He has been a reporter for Bloomberg News, Dow Jones, the Wall Street Journal, the Financial Times and the Guardian.

More stories like this are available on bloomberg.com/opinion