The story so far: The Union Civil Aviation Minister, Jyotiraditya Scindia, has said that the Government of India is exploring the possibility of inviting manufacturers of Electric Vertical Take off and Landing (eVTOL) aircraft to set up base in India. The Minister had been on a visit to the U.S. and Canada in April and in his interactions with key players in the industry, it was said that several eVTOL players were ‘keen on setting up production centres’ in the country. In late May, while speaking at “India@2047”, which was part of the seventh edition of the India Ideas Conclave in Bengaluru, the Minister also said that India is in ‘conversation’ with a number of eVTOL producers — the implication being a futuristic vision for India.
As the acronym suggests, an electric vertical take-off and landing (eVTOL) aircraft is one that uses electric power to hover, take off, and land vertically. Most eVTOLs also use what is called as distributed electric propulsion technology which means integrating a complex propulsion system with the airframe. There are multiple motors for various functions; to increase efficiency; and to also ensure safety. This is technology that has grown on account of successes in electric propulsion based on progress in motor, battery, fuel cell and electronic controller technologies and also fuelled by the need for new vehicle technology that ensures urban air mobility (UAM). Thus, eVTOL is one of the newer technologies and developments in the aerospace industry.
An article in Inside Unmanned Systems, a leading business intelligence platform, describes eVTOL as being “a runway independent technological solution” for the globe’s transportation needs. This is because it opens up new possibilities which aircraft with engines cannot carry out in areas such as manoeuvrability, efficiency and even from the environmental point of view. The article adds that there are an estimated 250 eVTOL concepts or more being fine-tuned to bring alive the concept of UAM. Some of these include the use of multi-rotors, fixed-wing and tilt-wing concepts backed by sensors, cameras and even radar. The key word here is “autonomous connectivity”. Some of these are in various test phases. There are also others undergoing test flights so as to be certified for use. In short, eVTOLs have been likened to “a third wave in an aerial revolution”; the first being the advent of commercial flying, and the second, the age of helicopters.
An article in Avionics International says the roles eVTOLs adopt depends on battery technology and the limits of onboard electric power. Power is required during the key phases of flight such as take off, landing and flight (especially in high wind conditions). There is also the important factor of weight. BAE Systems, for example, is looking at formats using a variety of Lithium batteries. Nano Diamond Batteries is looking at “Diamond Nuclear Voltaic (DNV) technology” using minute amounts of carbon-14 nuclear waste encased in layered industrial diamonds to create self-charging batteries. There are some industry experts who are questioning the use of only batteries and are looking at hybrid technologies such as hydrogen cells and batteries depending on the flight mission. There is even one that uses a gas-powered generator that powers a small aircraft engine, in turn charging the battery system. But whatever the technology, there will be very stringent checks and certification requirements.
As the technology so far is a mix of unpiloted and piloted aircraft, the areas in focus include “crash prevention systems”. These use cameras, radar, GPS (global positioning system) and infrared scanners. There are also issues such as ensuring safety in case of powerplant or rotor failure. Aircraft protection from cyberattacks is another area of focus.
A third area is in navigation and flight safety and the use of technology when operating in difficult terrain, unsafe operating environments and also bad weather.
There is general agreement that the eVTOL world is moving forward based on the spark provided by NASA researcher Mark D. Moore who came up with the concept of a personal (one man) air vehicle while working towards his doctorate. Called the “Puffin” and thought of in 2009-10, it was about four metres tall and with a wingspan of 4.4 metres. It had 60hp electric motors that powered two propellers. Its other specifications included a four-point landing gear, a weight of 272kg, 45kg of batteries, a pilot payload of about 90kg, fetching it a total weight of 407 kg. Its top speed was under 245 kmph with a range of about 80km. A prototype was unveiled in 2010 and the concept was discussed at a conference on aeromechanics in 2010, according to an article in Electric VTOL News. In his paper, “NASA Puffin Electric Tailsitter VTOL Concept”, Moore described “electric propulsion as offering dramatic new vehicle mission capabilities, .... but the only penalising characteristic” being “the current energy storage technology level”.
Since then there have been a number of ideas by industry, such as the Volocopter VC1 from Germany and the Opener BlackFly from the U.S. The top aircraft manufacturers, Airbus and Boeing, have also joined the race. Airbus unveiled its prototype, Vahana Alpha One or the Airbus Vahana (from the Sanskrit Vahana), at the Paris Air Show in 2017. It was pitched as a “cost-comparable replacement for short-range urban transportation” based on a fan-run tilt-wing design. Prototypes made test flights. Airbus then shifted to the “CityAirbus” project (air taxi) which has propellers and direct-drive electric motors.
Boeing is working on the Boeing Passenger Air Vehicle, as an “American autonomous personal air vehicle prototype”. However, the major disruptors have been start-ups, backed by huge dollar flow.
A company, Lilium, started in 2015, which claims to be the “developer of the first all-electric vertical take-off and landing eVTOL jet”, says that it is moving towards developing prototypes “designed to extract over 100kW of power from a system weighing just over 4kg” — which gives us an idea of the advancements. Its Lilium Jet theory has been designed for concepts such as private flights, six-seater passenger flights, or no seating for the zero-emissions logistics market.
It says that the concept looks to connect towns and cities (40km-200km) at speeds of up to 300km/h. It has called this as aimed at Regional Air Mobility, which it clarifies is not to be confused with Urban Air Mobility (UAM) — connecting intra-city points over shorter distances, or less than 20 km. It is also working on a seven-seater model, for use in existing helipads; In the U.S., for example, this would mean approximately 14,000 possible locations. The power demand across different phases of flight and the predicted range have been discussed in detail in a technology paper.
China, Israel and the U.K too have programmes to look out for.
Electric VTOL News, for instance, has a World eVTOL Aircraft Directory. Started in 2016 and listing half-a-dozen known designs, it has now progressed to categorising almost all known electric and hybrid-eVTOL concepts. Categories are: “Vectored Thrust”, where any thruster is used for lift and cruise; “Hover Bikes/Personal Flying Devices”, which are single-person eVTOL aircraft and in multicopter-type wingless configurations; “Lift and Cruise”, where independent thrusters are used for cruise and lift without any thrust vectoring; “Wingless (Multicopter)”, or where there is no thruster for cruise but only for lift; and “Electric Rotorcraft” or eVTOLs that use a rotor, such as an electric helicopter or autogyro.
Some companies have concepts that are aimed at dual certifications by regulatory agencies in the western world. In March this year, the Federal Aviation Administration (FAA) and the United Kingdom Civil Aviation Authority announced being engaged in discussions focused on “facilitating certification and validating new eVTOL aircraft, their production, continued airworthiness, operations, and personnel licensing”. Both bodies also highlighted the need to maintain very high safety standards. Further to this, eVTOL technology is to use existing regulatory frameworks despite being in the form of new and emerging technologies. The FAA has clarified that it plans to certify eVTOLs as powered-lift aircraft (an existing category) but in future, “develop additional powered-lift regulations” for innovation in operations and pilot training. It plans to use a “special class” process in 14 CFR 21.17(b) to oversee the unique features of emerging powered-lift models. But this certification will use the performance-based airworthiness standards found in Part 23 of the FAA regulations. The FAA’s important clarification that the changes will be gradual has been welcomed by eVTOL developers, who are leaning on the Part 23 framework as the bedrock for type certification.
EVTOL certification is also complex because of planned operations within urban areas, new battery systems and the need for higher levels of automated redundancy.
The Paris summer Olympics 2024 is expected to be the big moment, according to an article in Bloomberg. France is working on two dedicated routes to transport passengers. Landing and takeoff zones at the Pontoise-Cormeilles-en-Vexin hub are being tested on parameters such as noise levels, integration of drones and eVTOLs with existing air traffic, battery charging and also maintenance.
Mr. Scindia has been reported as asking Beta Technologies, which has a partnership with the Blade group (it has a presence in India), to look at the Indian market. An official from Blade India told The Hindu that Blade is an urban air mobility company that aims to connect places that are heavily congested and also not well connected by air services. The concept of ‘Advanced Air Mobility’ comes in, i.e., connecting places through vertical aircraft and thus skipping road travel. This is being done now by helicopters, but eVTOLs will step into this space.
The official said that Blade U.S. is currently working with electric vertical aircraft (EVA) manufacturers such as Beta Technologies and has partnered with them for an all electric fleet by the year 2024. eVTOLs are noise free, have a zero carbon footprint and are more affordable. Beta technologies and other EVA manufacturers have been extended an invitation to manufacture in India.
Amit Dutta, Managing Director, Blade India is the chairperson of the Confederation of Indian Industry (CII) Taskforce for Urban Air Mobility. In his suggestions for policy and regulation changes to better integrate EVAs, he has advised regulatory authorities in India to look at: formulating regulations for pilotless vehicles, airworthiness certifications, and the need for a pilot’s licence; implementing efficient energy management systems, onboard sensors, collision detection systems and advanced technologies such as artificial intelligence; having in place infrastructural support such as take-off and landing zones, parking lots, charging stations and what are called vertiports; creating a robust air traffic management system that is integrated with other modes of transportation, and putting in place a database to ensure operational and mechanical safety.
In addition to this, there are psychological barriers that need to be overcome when it comes to flying in a fully autonomous aircraft. Therefore, the official added, there needs to be a document that outlines compliance for eVTOLs and also aligns frameworks to meet the standards adopted in commercial aviation, especially when it comes to safety. The current timeline for certification with India’s Directorate General of Civil Aviation is two years. The Blade India official says that there is a need for a committee to spell out the guidelines for eVTOL operations and speed up the process.
The global market for eVTOLs was put at $8.5 million in 2021 and is to grow to $30.8 million by 2030. The demand will be on account of green energy and noise-free aircraft, cargo carrying concepts and the need for new modes of transport.
According to the Blade India official, the UAM market is expected to expand at a compound annual growth rate of 25% between 2018-25. By 2025, it is anticipated to be a $74 billion market. This includes the eVTOLs market since UAM ideally focuses on the use of eVTOLs, the official added.