KEY PLAYERS IN THE EMERGING EVTOL AIR TAXI MARKET
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 will also run on zero-local-emission electric power and many models suggest they will cost around the same per kilometre as a ride share.
Experts appear to agree that mostly they will be pilotless automatons, even cheaper and more reliable than the earliest piloted versions. Should the onboard autopilot computers become confused, remote operators will take over and save the day as if they are flying a DJI 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 said 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 is not exactly cheap to take a 40-mile (64 km) Uber ride.
Rolls-Royce, famous for its aerospace engines, is getting on board with electric propulsion with this hybrid VTOL conceptRolls-Royce. The technology does not feel far away. Electric multirotors deliver excellent hover stability thanks to the enormous, near-instant torque production of electric motors, which can respond very quickly to stabilise an aircraft as
wind conditions move it around, whilst there are a plethora of different takes on how these machines should be built. 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 is stopping us from having eVTOL air taxis today?
The first is the same problem that is holding back high-performance electric motorcycles: current lithium battery technology simply does not allow you to carry enough energy yet. Until energy density is at least doubled, most of these designs do not offer range endurance long enough to make them commercially viable. These big battery packs will also require charging, which would ground the aircraft for a significant time.
The second is certification. At this stage, we are not aware of any eVTOL design that is certified as a fully commercially operable aircraft and while some endeavours are finding ways to push forward around the edges of the law, the fact remains that these are entirely new categories of aircraft, as well as 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 propeller, 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 designs should be very safe. However, ballistic parachutes can only save you above a certain altitude, maybe 120 feet or so. Below that, they do not have time to open up, which means that every time you take-off or land in one of these machines, you are exposed to a window of time in which total system failure would drop you like a stone.