eVTOLs (Electric Vertical Takeoff and Landing) are electrified VTOL (Vertical Takeoff and Landing) aircraft characterized by their ability to lift off from the ground vertically through electric propulsion. VTOL refers to vehicles such as helicopters and tilt-rotor aircraft that unlike traditional aircraft do not require a runway for take-off. eVTOLs offer potential advantages compared to other aircraft with lower noise profiles and zero-emission flights. Combining these advantages with shorter journey times has led to considerable interest in eVTOLs for use as "air taxis."
Advances in materials science, electric motors, and battery technologies have increased the viability of electric aircraft. eVTOLs combine multiple electric motors with propellers and large onboard batteries, to be able to transport passengers and cargo up to 150 to 250 miles on a charge. For example, Joby Aviation states its five-seat eVTOL has a maximum range of more than 150 miles with a top cruising speed of 200 miles per hour.
The adoption of eVTOL aircraft faces significant technology, infrastructure, and regulatory challenges. eVTOL aircraft need areas to land with suitable charging facilities. The industry also requires regulation in terms of both vehicle and pilot certification.
There are three main types of eVTOL operation:
- Tilt thrust—propellers can change position in order to generate lift and position the aircraft forward-facing for propulsion.
- Lift and cruise eVTOLs—multiple propellers provide lift (like a helicopter), with a second fixed motor providing forward propulsion.
- Multirotor systems—multiple fixed rotors provide lift and forward thrust when the vehicle is tilted forwards.
While each type has benefits and drawbacks, tilt thrust designs are the most popular option among eVTOL firms developing aircraft for moving passengers and cargo long distances. Tilt thrust currently shows the most promise for longer ranges and high payloads. The added engineering challenges of tilt thrust designs are possible due to advancements in electric motor design.
The vertical flight society maintains an eVTOL aircraft directory, categorizing all known electric and hybrid-electric vertical takeoff and landing concepts separated into the following types:
- Vectored thrust—any of its thrusters are utilized for both lift and cruise
- Lift + cruise—independent thrusters for cruise vs for lift without thrust vectoring
- Wingless (multicopter)—thruster is only used for lift
- Hover bikes/personal flying devices—single person eVTOL where the pilot stands or sits on a saddle
- Electric rotorcraft—aircraft utilizing a rotor (e.g. electric helicopter, electric autogyro)
A number of companies are currently developing eVTOL aircraft, including traditional aerospace companies and new startups. Some of the major players in the eVTOL industry include the following:
- Joby Aviation
- Beta Technologies
- Wisk Aero
- Bell Helicopter
- Jaunt Air Mobility
- Archer Aviation
- Vertical Aerospace
- Urban Aeronautics
2021 saw significant investment in eVTOL companies, including three special purpose acquisition company (SPAC) deals for Joby, Archer, and Lilium raising over $2.5 billion combined (Joby accounting for $1.1 billion).
As well as vehicles, a number of companies are developing the infrastructure required for eVTOL:
- PS&S, an architecture and engineering design company developing vertiport designs for urban, suburban, and waterside environments. These designs include landing pads, charging stations, and terminals for customers waiting to fly.
- Archer Aviation and REEF Technology are both looking to co-opt underutilized parking garages into vertiports in urban areas.
eVTOLs were first introduced in 2009 with NASA engineer Mark Moore's Puffin personal air vehicle concept. The original render video was released on November 11th, 2009. It showed the conceptual design based on an electric propulsion system to provide vertical takeoff and landing with a proposed variable rpm electric motor that could accomplish a low tip speed prop-rotor (400 ft/sec tip speed at hover and 200 ft/sec at cruise) and reduce noise levels by an order of magnitude.
2011 saw the first flights for a number of eVTOL designs, including the following:
- First unmanned tethered flight of the AgustaWestland (now Leonardo Helicopters) Project Zero on June 1st in Cascina Costa, Lombardy, Italy.
- First free flight of the Solution F electric helicopter demonstrator in Venelles, France on August 12th.
- First manned flight of Opener SkyKar Rebel proof-of-concept vehicle on October 5th. The vehicle was flown by the founder of Opener, in his front yard, in Warkworth, Ontario, Canada.
- First manned flight of the Volocopter VC1 prototype at the Rheinstetten Glider Field, Karlsruhe, Germany on October 21st.
- First unmanned hover flight of the Zee Aero Proof of Concept (POC) aircraft in the San Francisco Bay Area, California, USA, exact date unknown.
On October 27, 2016, Uber published a white paper titled "Fast-Forwarding to a Future of On-Demand Urban Air Transportation." Created by Uber Elevate (Uber's air taxi initiative), the paper detailed Uber's vision for and the feasibility of on-demand aviation. On May 8th, 2018, at the Uber Elevate Summit in Los Angeles, the company unveiled its Uber Air Prototype air taxi. The design incorporates four sets of staked horizontal rotors for lift and a tail-mounted propeller. In December 2020, Uber offloaded its air taxi unit "Elevate" to Joby Aviation in a complex deal that saw Uber invest $75 million in the eVTOL startup.
In February 2021, Joby Aviation announced it will merge with SPAC Reinvent Technology Partners (RTP) in a deal providing the company with approximately $1.6 billion in cash, resulting in a post-money valuation of $6.6 billion. The same month United Airlines formed a strategic partnership with electric air taxi developer Archer including equity investment and an order for $1 billion worth of the startup’s aircraft, expected to be certified with the Federal Aviation Administration (FAA) and begin volume manufacturing by 2023. Archer will merge with SPAC Atlas Crest Investment Corp in a deal expected to provide $1.1 billion in gross proceeds, valuing the start-up at $3.8 billion and resulting in the company being listed on the New York Stock Exchange.
In March 2021, German company Lilium unveiled its new seven-seat eVTOL along with plans to go public through a SPAC merger with Qell, led by former General Motors North America president Barry Engle. The deal values the company at approximately $3.3 billion with total gross proceeds to the company around $830 million, including private investment in public equity (PIPE) totaling $450 million. PIPE contributors include Baillie Gifford; funds and accounts managed by BlackRock, Tencent, Ferrovial, LGT and Lightrock, Palantir, FII Institute; and private funds affiliated with PIMCO.
Joby combines with Reinvent Technology Partners, a SPAC run by LinkedIn co-founder Reid Hoffman and Zynga founder Marc Pincus. The deal brings Joby more than $1 billion in funding which the company plans to use for FAA certifications and developing its electric aircraft.
The deal values the company at approximately $3.3 billion with total gross proceeds to the company around $830 million.
The deal will provide the company with approximately $1.6 billion in cash, resulting in a post-money valuation of $6.6 billion.
Archer will merge with SPAC Atlas Crest Investment Corp in a deal expected to provide $1.1 billion in gross proceeds, valuing the startup at $3.8 billion and resulting in the company being listed on the New York Stock Exchange.
The design incorporates four sets of staked horizontal rotors for lift and a tail-mounted propeller. The prototype was displayed at the company's second annual Uber Elevate Summit in Los Angeles.
Flight took place at the AgustaWestland facility in Cascina Costa, Lombardy, Italy.
The Puffin personal air vehicle concept was based on an electric propulsion system providing vertical takeoff and landing with a proposed variable rpm electric motor that could accomplish a low tipspeed prop-rotor (400 ft/sec tip speed at hover and 200 ft/sec at cruise), reducing noise levels by an order of magnitude.
Flying vehicles of the future: Companies racing to develop eVTOL "air taxis"
April 17, 2022