Electric VTOL air taxis are one of the great emerging technologies of our time, promising to unlock the skies as traffic-free, high-speed, 3D commuting routes. Much quieter and cheaper than helicopter travel, they’ll also run on zero-local-emission electric power, and many models suggest they’ll cost around the same per mile as a ride share.
The technology doesn’t feel far away. Electric multi-rotors deliver excellent hover stability thanks to the enormous, near-instant torque production of electric motors, which can respond very quickly to stabilize an aircraft as wind conditions move it around. And there are a plethora of different takes on how these machines should be built.
Eventually, the market seems to agree, they’ll be pilotless automatons, even cheaper and more reliable than the earliest piloted versions. Should the onboard autopilot computers get confused, remote operators will take over and save the day as if they’re flying a Mavic drone, and every pilot gone will be an extra passenger seat in the sky.
Large numbers of eVTOL air taxis will change the way cities and lifestyles are designed. Skyports atop office buildings, train stations and last-mile transport depots will encourage multi-mode commuting. Real estate in scenic coastal areas might boom as people swap 45 minutes crawling along in suburban traffic for 45 minutes of 120 mph (200 km/h) air travel, and decide to live further from the office.
Several companies have told us they believe they can deliver an air taxi service for about the same price as it would cost to take an Uber. Mind you, this assumes medium to long distance trips, and it’s not exactly cheap to take a 40-mile (64 km) Uber ride.
Some designs are as simple as big multirotors with passenger cabins. Others attempt to extend range by adding complexity in the form of tilting rotors and multi-mode flight; hovering like a multirotor, they transition to wing-assisted forward flight, which is much more efficient but dynamically more complicated.
What’s stopping us from having eVTOL air taxis today, then?
These machines still have a few major challenges left to overcome.
The first is the same problem that’s holding back high-performance electric motorcycles: current lithium battery technology simply doesn’t allow you to carry enough energy yet. Until energy density is at least doubled, most of these designs don’t offer range endurance long enough to make them commercially viable. These big battery packs will need charging, too, which would ground the aircraft for a significant time.
The second is certification. At this stage, we’re not aware of any eVTOL design that’s certified as a fully commercially operable aircraft, and while some endeavors are finding ways to push forward around the edges of the law, the fact remains that these are entirely new categories of aircraft, and the process of certifying, testing and regulating them is going to be monstrously expensive and time consuming.
The third impacts the second: safety. Electric VTOL aircraft can offer all sorts of redundancy options that no other aircraft can match. Take out a prop, or a motor, or even a few of them, and most of these designs can still fly thanks to distributed propulsion and smart software. Ballistic parachutes can be fired to bring them down gently in the case of total catastrophic failure. In the vast majority of cases, these things should be very, very safe.