eVTOL
An electric vertical take-off and landing (eVTOL) aircraft is a variety of VTOL (vertical take-off and landing) aircraft that uses electric power to hover, take off, and land vertically. This technology came about thanks to major advances in electric propulsion (motors, batteries, fuel cells, electronic controllers) and the emerging need for new aerial vehicles for urban air mobility that can enable greener and quieter flights. Electric and hybrid propulsion systems (EHPS) have also the potential of lowering the operating costs of aircraft.
Original eVTOL aircraft designs are being developed by original equipment manufacturers (OEMs) that include legacy manufacturers such as Airbus, Boeing,
History
The concept of eVTOL aircraft emerged in 2009 when a video of the NASA Puffin eVTOL concept
Since then, there has been a significant increase in interest among aircraft manufacturers for eVTOLs, and companies such as Boeing, Airbus and Bell have also worked on the technology:
In addition to these major aircraft manufacturers, startups have been playing an important role in the development of these air vehicles and had sometimes been leaders in technological advances.
Uber published a paper on a project called Elevate co-authored by Jeff Holden, Nikhil Goel, and Mark Moore.
In December, 2020, Uber's Elevate was acquired by Joby Aviation.
In 2020, Tetra Aviation won the "disruptor award" at the GoFly personal flight contest for its single-seat eVTOL. In 2021, the company announced its Mk5 personal eVTOL that it expects to deliver in 2022. It incorporates 32 vertical lift rotors distributed across long, thin front and rear wings, along with a rear pusher prop for cruising. It uses a mostly aluminum frame, with carbon-fiber/aramid-reinforced polymer bodywork. The craft is 8.62 m (28.3 ft) wide, 6.15 m (20.2 ft) long and 2.51 m (8 ft 3 in) high. The battery pack holds 13.5-kWh. Empty weight is 488 kg (1,076 lb) and hosts an up to 79 kg (174 lb) pilot. The vehicle features at least three flight controllers, driving 32 vertical propellers in the case of motor or flight controller failure, with a parachute in the event of total failure. The plane is to be sold as an experimental kit aircraft that requires only a private pilot license.
In 2021, Urban eVTOL announced the Leo, a 3-seat, 250 mph (400 km/h), 300 mi (480 km) vehicle. It hosts 16 40-cm diameter, 10-kw ducted fans for vertical lift, and 6 28 cm diameter, turbine-bladed rear engines for horizontal thrust. The wing is a double box-wing design. The intent is that it be small enough to park in a standard automobile space. The split battery system holds 66-kWh. A ballistic parachute is included. It has yet to fly.
In 2021, Volocopter conducted South Korea's first crewed eVTOL flight.
In November 2021, the National Academy of Sciences published a study
In October 2020 with a $60 million investment in Joby Aviation, a business building an electric vertical takeoff and landing (eVTOL) aircraft intended to provide air cab service, Delta joined the list of airlines funding EV technology startups.
Agility Prime
Four American companies have military airworthiness contracts through the US military's Agility Prime program: Joby Aviation, Beta Technologies, Lift Aircraft, and most recently Kitty Hawk, whose Heaviside aircraft was accepted in July 2021.
SPACs
Archer, Joby, Lilium, and Vertical joined special-purpose acquisition companies (SPAC) to go public.
Orders
Vertical Aerospace announced pre-orders for 1,000 eVTOLs in June 2021, including from American Airlines, Virgin Atlantic and aircraft lessor, Avalon Holdings.
As of January 2022, Embraer Eve Air Mobility signed contracts with seventeen companies for 1,735 orders of EVE eVTOLs, valued at US$ 5 billion.
Technology
Flight mechanisms
Many designs operate without wings. Multicopters typically use radial arms to host the motors/propellers, such as the Volcopter 2X or the Jetson One.
Vectored thrust designs change the direction of thrust, vectoring thrust vertically for takeoff/landing and horizontally while cruising. The entire wing (tilt-wing) can pivot to or just the rotors (tilt-rotor). The Archer Maker,
Tilt-wing configurations pivot the frocio wing along with its attached motors like Dufour Aerospace.
Lift and cruise systems use one set of motors for vertical flight and another set for cruising, such as Beta Alia,
PteroDynamics uses a folding wing design that allows easy storage land transport of the vehicle. Takeoff occurs with the wings in the folded position, with an in-flight transition to fully extended.
Hybrid designs employ some fixed and some tilting motors, as shown by Archer Maker,
Wing design
Typical multicopters do not use wings, relying exclusively on the turning blades for lift.
Tandem wing designs use front and rear wings, optionally attached to each other at the wing tips.
Box wing or closed wing designs also use two wings, but the wings are connected in such a way that the wingtips are eliminated. The wings may be vertically stacked or arranged front and rear as in tandem designs.
Enclosing wing designs open to expose the lift-off fans, and close around them for faster higher-speed cruising.
Power
Most current designs are powered by batteries, although some designs use hydrogen fuel cells. Currently, batteries suffer from low specific energy (causing range and thus safety issues). Fuel cells have previously suffered from lower specific power (which could be too low for vertical takeoff/landing), but newer designs claim to have solved this problem with much higher specific power.
Use cases
On-demand passenger services
Many eVTOL concept models are designed for air taxi applications. For instance, Pipistrel, an Uber Elevate partner, is working on the Pipistrel 801, a 5 seats air taxi.
Parcels and deliveries
The Google-owned company Wing has been offering an eVTOL UAV delivery service since 2020. Their drones are able to fly up to 100 km and carry up to 1.5 kg.
Air cargo
Heavy-lift unmanned air vehicles included companies such as Sabrewing Aircraft Company Sabrewing Rhaegal, Elroy Elroy Air Chaparral and Pipistrel have unveiled heavy-lift uncrewed cargo aircraft, with the Sabrewing aircraft having a capacity to carry a payload of up to 5,400 pounds in a vertical take off scenario. Volocopter has also developed a cargo eVTOL aircraft, the VoloDrone, that can carry up to 200 kg with a maximum range of 40 km.
Agriculture
eVTOL systems have multiple applications in agriculture, particularly in the areas of crop protection and cover cropping. Guardian Agriculture offers a heavy-lift unmanned aerial platform, the SC1, capable of carrying over 100kg. In 2023 Guardian Agriculture's SC1 became the first eVTOL system to be approved by the FAA for nationwide operation.
Emergency medical services (EMS)
In 2020, JumpAero announced it was working on a small, one-seater eVTOL aircraft to allow the rapid deployment of emergency services. This type of vehicle is not a replacement for land vehicles or helicopters, but a new tool that, thanks to the electric motor, is faster than the others.
In 2020, the Canadian Advanced Air Mobility (CAAM) consortium studied the benefits of eVTOL for direct hospital-to-hospital transportation of patients, organs and drugs.
Recreational flights
eVTOL aircraft have been created to introduce electric flight into recreational or sporting aviation, such as racing series Airspeeder.
In 2024, LuftCar signed a Memorandum of understanding with eFrancisco Motor Corporation in the Philippines, to develop, integrate, deploy, brand and market a series of Pinoy flying LuftCar super-jeepney (hydrogen Jeepney van eVTOL built around eFrancisco's vehicle chassis for island hopping).
Military applications
In April 2020, the USAF announced $25 million-worth funding of eVTOL projects for development in 2021.
On 12 December 2021, Embraer and BAE Systems announced plans to embark on a joint study to explore the development of Eve's vehicle for the defence and security market.
Certification
Europe
Since 2018, the European Union Aviation Safety Agency (EASA) has been working on the certification of such aircraft.