Aiming at the intercity transportation segment, established and new OEMs join the eVTOL race.
By Sean Connor
Director of Unmanned Systems Discover Technology Intl
Over the past 18 months, billions of dollars have been injected into startup manufacturers and air taxi services in the hopes of making all-electric urban transport the new standard for city dwellers and airport travelers of the near future.
Flight test programs by leading electric vertical takeoff and landing (eVTOL) makers around the globe continue to reach key milestones, graduating from concept designs to subscale demonstrator flights, and even pre-production tests.
One of the objectives of these new technology aircraft is a commitment to zero emission transport, which has led to thousands of conditional orders from the world’s largest air carriers and charter services. Another goal, from an operator perspective, is the dramatic reduction in direct operating costs, much longer intervals for required powerplant maintenance, and far less infrastructure for support.
Another key aspect of eVTOL aircraft is that they are aimed at a totally different market segment – bringing aviation to intercity transportation. The question for professional pilots and operators becomes whether the business case and aircraft performance are realistic for this proposed new market segment.
So, performance matters in the areas of range, payload, and speed. Looking at the emerging UAM contenders, a combination of new designs, new engines, and serious professional experience in aircraft production are about to fly into the market.
eVTOL aircraft and OEMs
Airbus, one of the early entrants into the eVTOL concept race, has both an environmental and business commitment to the success of UAM. The manufacturer has seen the need for new strategic partnerships to achieve zero emissions and competitive performance, which are often at odds.
After several years of research and innovation including 2 eVTOL demonstrators – the Vahana and CityAirbus – Airbus is now progressing toward its production design, with the latest CityAirbus NextGen model.
The all-electric, 4-seat multicopter/fixed-wing concept is targeting a 50-mile range at approx 105 kts to achieve zero emission flight applications for cities, and to improve the efficiency of transport between urban and suburban environments.
CityAirbus NexGen does not require moving surfaces or tilting parts for the transition from hover to cruise – a distinguisher among other leading eVTOL designs. Airbus has set a goal for a prototype flight by 2023, with certification by 2025.
Bell, an aircraft company with a long history of vertical flight machine certification and mass production, has designed the Nexus 6HX and 4EX aircraft with ducted fans. The design has a historical precedent in the Bell X-22, which first flew in 1968.
The Bell Boeing V-22 Osprey, an operational production aircraft with tilt-wing and complicated transmissions, puts into play a manufacturing foundation.
And when you consider Bell’s aggressive play with the V-280 Valor, you can see that moving wings and driveshafts that enable both vertical and forward flight will be airworthy sooner rather than later.
Targeting a range of 150 miles and max speed of 155 kts for the 6HX, the reach of this aircraft will be in the expected class of Air Taxis, with enough speed and reserves to deal with the practicality of all-weather operations.
In contrast, the all-electric 4EX, with a range of 60 miles and speed of approx 130 kts, was driven by market requirements for an eVTOL to serve cities as an intra-urban mobility provider. The flight deck configuration is intended to start with a pilot, and its ducted fans will offer both lift and safety to the operation.
Designing these aircraft from the inside out, Bell is focused on delivering a passenger-centric experience with a sleek and spacious cabin that will optimize commuter comfort. A full-scale demonstrator is expected in the mid-2020s.
Eve UAM, an Embraer company, has designed an eVTOL with a combination of ducted fans and rotors, with a planned service entry of 2026. Brazil’s ANAC and Eve recently agreed the type certification process.
One interesting development at Eve is that the company is reportedly running an operational simulation in Rio de Janeiro, with 4 daily flights using a Bell 505 helicopter. The idea is to develop services and procedures for the company’s future operations, and most likely supports the basis for both designs and orders.
Tickets for this service were advertised at $18 for a 15-minute flight, the end goal being to have a validated operational concept.
Joby S4 eVTOL is backed by innovation and manufacturing giant Toyota. The aircraft is faster than most, with a top speed of around 170 kts, and can carry a 4000-lb payload. The company has established a Part 23 certification basis with FAA, which, according to Joby, began in February 2022.
Clearly aimed at Part 135 operations, the S4 eVTOL has been a leader in the process of certification for this new class of aircraft. Joby’s design sports composite materials for weight savings, and has achieved a continuous 154-mile flight in 1 hr 17 min.
Beta Technologies Alia is a design that combines fixed rotors and a pusher prop, with a range of 250 miles and a reported payload of 6000 lb with 2 passengers plus cargo. The company’s engineering focus on a specific airframe, battery, and rotor blade designs most likely were key to winning orders from UPS for time-sensitive cargo deliveries.
One major innovation is the rapid charging system, which is designed as a multimodal solution to include electric vehicles and aircraft for both on- and off-airport operations. A concept charging pad features a look into the future of vertiport infrastructure, including an elevated landing deck, hotel units for crew rest, and a control center for mission briefing and operational management.
The company has a goal of 2024 for service entry. Overall, the aircraft is positioned to compete for a variety of missions in the vertical lift market.
eVTOL flight deck instrumentation
For the most part, basic flight instruments still prevail to control the vehicle, with lessons learned from conventional vertical flight regimes. Operating in both controlled and uncontrolled airspace will be expected by the major airlines as well as independent Part 135 operators.
This means that pilots will be required, so training, operations, and avionics design that actually make flying easier are going to be in top demand.
Honeywell has been selected for the Vertical Aerospace VX4, which is based on the company’s new Anthem flight deck solutions.
The design is all touch controls and prompts, with what Honeywell notes as “intuitive” and “simplified vehicle operations.” Honeywell’s work in detect-and-avoid radar, small inertial navigation systems, and controls, is designed to “flatten the curve to safely fly.”
Beta Technologies Alia 250 has a single primary flight display with supporting secondary display for communications and navigation. Beta has reached an agreement with CAE for training for both pilots and mechanics to match 2024 service entry dates.
Another aspect of eVTOL avionics is what actually flies the aircraft. Airbus has selected Thales for its CityAirbus flight control computers.
This ensures real flying qualities that can be certified with EASA’s new eVTOL regulations. With its roots deep into all forms of transportation, including non-aviation markets like metros, light rail, trams, and buses, Thales will enable digital connections that translate into timely efficiencies.
Who will capture the market?
The major transition occurring now is the conversion from concepts and artwork to flying machines that can be certified. One much debated topic has been the basis of certification, and several of the leading contenders have settled on means to aircraft certification and dates for entry into service.
With the many different designs and apparent means of propulsion for vertical and forward flight, the question of pilots and flight decks gets to the front of the discussion quickly, especially with regulators.
The clearly stated operating concepts of fully autonomous, passenger-only aircraft are the end objective by many of the contenders. And, most likely, this is years away. The near term looks to be more conventional, with single-pilot Part 135 operations along helicopter routes and, in some cases, low- to mid-altitude airways.
Another key factor in this new aircraft industry is the order book. Eve and Vertical Aerospace, as 2 examples, have secured more than 3000 orders between them, with a backlog of $10.5 billion. The orders are interesting, coming from major carriers such as American Airlines, UPS, and United Airlines, and could address the challenge of getting more passengers to major airports for gateway flights.
The investment trail seems to have different angles, such as auto leaders Toyota and Hyundai, as well as Boeing. In all cases, it’s clear that real money and experience in both aviation and manufacturing now have a serious stake in the game.
Which brings us back to the questions of economics and performance. Fueled by unprecedented levels of investment and the brightest minds in the industry, coupled with the momentum of new infrastructure and clean energy demands, this is actually going to happen. The primary issue will be affordability to the passenger, where direct operating costs always include a pilot, flight attendants, maintenance, and an FBO.
Sean Connor is director of unmanned systems at Discover Technology Intl. He is a sUAS pilot, policy analyst, and researcher specializing in the development of advanced avionics, drones, and urban air mobility.