Right now, electric airplanes are not only being developed and tested, but they’re also being certified, produced and put into service.
In Europe, type-certified electric airplanes are coming off the production line.
In Western Canada, a seaplane commuter airline is making plans to electrify its entire fleet for paying passengers.
In the C-suites at some of the world’s largest airframers, executives are talking seriously about the changes in air traffic management and the infrastructure that must be built to accommodate the first generation of electric aircraft.
More than ever before, the desire for environmentally friendly aircraft — combined with leaps in technology — are driving the aviation industry into a new era. It’s a future that promises to include a wide range of designs, including fixed-wing, tilt-rotor, ducted fans — many capable of vertical takeoff and landing — powered by lithium-ion batteries, hydrogen fuel cells or other means.
“Look at how many startups are out there, doing different things,” said Andre Stein, head of Strategy for EmbraerX — Embraer’s research and development arm. They’ve been very busy lately figuring out the secrets of eVTOL — electric vertical takeoff and landing aircraft. “We need to disrupt ourselves before someone else does.”
Like Embraer, Rolls-Royce is also committing serious resources for several electric R&D programs. The aviation propulsion giant is developing a one-seat, battery-driven 300-mile-an-hour research airplane called ACCEL.
“In general, we see electrification in all of our market segments as a key tool to basically achieve sustainability in all the markets that we play in,” said Mike Mekhiche, deputy director at Rolls-Royce Electrical.
Changing How We Fly
Eventually, electric aircraft will change the way travelers think about flight and transportation, industry leaders say. In 30 years, it may be commonplace for people to board small, on-demand eVTOL air taxis at neighborhood landing zones. Those eVTOLs — coordinated and tracked by air traffic management systems — would quickly zip passengers to local destinations or, for longer trips, to airports.
Electric airplanes with ranges of a few hundred miles could fly travelers to other regional airports.
International and transoceanic travelers may take an electric aircraft to an international hub airport, where they could board larger, long-range airliners — possibly powered by combustion engines that burn clean fuel.
“This whole combination will allow operators to start offering services to and from airports like never before, because it’s cheaper,” said Roei Ganzarski, CEO of electric motor manufacturer magniX. By 2025, Ganzarski predicts hundreds of electric aircraft will be flying in the world’s airspace.
Proponents say electric planes will not only be less expensive to operate, but also quieter and easier to maintain. Less maintenance, they say, means more planes doing business and fewer planes out of service for repairs.
As wonderful as it all sounds, virtually everyone acknowledges that significant social and technological hurdles must be overcome before dreams about widespread electric flight can become reality. Already, engineers and industry experts are hard at work trying to solve these challenges.
First Type-Certified Electric
If you need proof that the electric revolution is happening today, you can find it in the central European nation of Slovenia. There, a 31-year-old company named Pipistrel manufactures a type-certified electric airplane that flies up to 50 minutes without a drop of fossil fuel. Pipistrel’s two-seat trainer — dubbed the Velis Electro — wowed the aviation community last June when it won type certification by the European Union Aviation Safety Agency (EASA), the “world’s first fully electric aeroplane ever to receive type certification,” according to the company.
Pipistrel Group Chief Technical Officer Tine Tomažič believes all-electric platforms have an important role to fill in the coming years. However, as he told Aerospace Tech Review, “electric is not going to work universally, but it is going to work for shorter hops – between one to two hours of flying.”
Tomažič sees the long-term development of electric aviation rolling out in several phases.
First, he said, the world will see small, battery-powered, two-seaters enter service — as we are now. Then, the next five years will bring electric reengining of appropriate existing airframes originally designed for combustion engines.
From 2025-2030, Tomažič expects a wave of new airframe designs specifically for electric. As these aircraft enter service, they’ll add convenience to people’s lives by enabling faster delivery of goods direct to our doorsteps. Flights aboard electric aircraft will increase passenger comfort, Tomažič said, as they enjoy a quieter, smoother experience. “The general attitude toward flying, I think, will turn more positive,” said Tomažič.
Electrifying Existing Planes
The electric revolution is also underway in Vancouver, Canada, where magniX and seaplane airline Harbour Air have been test flying an electrified de Havilland DHC-2 Beaver. Their goal: to convert the airline’s entire fleet of Beavers to electric “eBeavers,” that would fly short passenger routes lasting about 30 minutes.
“By 2023 you’ll be able to buy tickets on electric airplanes,” magniX’s Ganzarski said, adding that he fully expects Harbour Air to be the world’s first electric airline.
The electric motor aboard magniX’s eBeaver prototype is powered by lithium-ion batteries. Although details about how the powertrain will be configured inside the plane aren’t finalized, Harbour Air Director of Maintenance Shawn Braiden said It’s possible that batteries could be stowed underneath the cabin floors, where fuel tanks were originally located.
“We’re going to try and do some more flight testing, but this motor is working; the batteries are working; the controllers are working,” Braiden said. “Everything’s working.”
When the eBeavers eventually enter service, preflight weight and balance adjustments are expected to undergo very few changes compared with traditional Beavers, Braiden said. If passengers and luggage exceed weight limitations, excess baggage will be held and transported on later flights.
“Refueling” eBeavers between flights isn’t expected to take much time, Braiden said. Ideally, batteries would be quickly swapped out with freshly charged batteries after every flight, he said, adding that, alternatively, the airline could use a quick-charge procedure on the batteries.
magniX has also converted and begun testing larger Cessna 208 “eCaravans,” which traditionally seat about nine passengers.
Harbour Air isn’t the only airline with electric dreams. Hawaii’s Mokulele Airlines and California-based Ampaire are now test flying a pair of converted hybrid-electric Cessna 337 six-seaters, in hopes of proving their effectiveness on short-haul demonstration flights later this year.
Hydrogen Fuel Cells
Instead of batteries, some electric aircraft developers have chosen to experiment with hydrogen fuel cells as a possible power source for aircraft motors. Batteries act as an energy storage device, while hydrogen fuel cells produce electricity through a chemical reaction by mixing hydrogen with oxygen. Fans say hydrogen fuel cells offer a more promising energy-to-weight ratio for larger aircraft.
In fact, last September in Cranfield, England, a startup called ZeroAvia briefly flew a Piper M Class, six-seater using hydrogen fuel cells.
A company press release called it the “world’s first hydrogen fuel cell powered flight of a commercial-grade aircraft.”
Interestingly, ZeroAvia said the flight raises hopes for “innovation that can reduce commercial challenges in the medium term, particularly important for the industry as it considers the post pandemic recovery.”
Longer-range flights are planned later this year.
All of this rising interest in hydrogen has gotten the attention of a fuel logistics company in Los Angeles called Universal Hydrogen. It has announced a partnership with magniX to sell hydrogen fuel cell conversion kits.
The kits are designed to retrofit the ATR 42 family of airplanes as well as de Havilland Canada DHC8-Q300s – better known as the Dash 8. These converted zero-emission electric regional airliners would seat about 40 passengers.
Super Batteries
So why is this revolution happening now?
What’s driving this race to reach the so-called “third era of aviation?” (Think of the first era as propeller aircraft and the second era as the Jet Age.)
Industry leaders say the Electric Age is happening because of multiple factors — including a growing global desire to cut fossil fuel emissions. It’s also being driven by significant leaps in battery technology.
Ganzarski at magniX credits electric carmaker Tesla and its co-founder Elon Musk for “launching a real revolution” to develop powerful and light lithium-ion batteries.
“When we started flying the Beaver and the Caravan, the lithium-ion batteries we had in those aircraft were about 180-190 watt hours per kilogram,” Ganzarski said. “Today we’re working with battery companies with lithium-sulfur and lithium-metal (batteries) at over 400 watt hours per kilogram. That’s more than double. And it’s been less than 12 months since we flew the Beaver. It just shows you the rapid pace of innovation.”
Decades ago, during the early days of the Computer Age, Moore’s Law observed that the number of transistors in a microchip doubles on average every two years. As engineers learn how to pack more energy into lighter batteries, will someone someday draw a similar observation?
As we all know, managing weight is so critically important to successful aircraft design. Obviously cutting battery weight while increasing battery energy density is key to unlocking electric’s full potential.
Musk has done much to trigger discussion around a so-called “magic number” for energy density in batteries. It’s an aspirational number that would represent a very powerful and light-weight battery that could have the potential to crack the electric aviation industry wide open and dramatically accelerate growth.
“I don’t think there’s such a thing as a magic number,” Rolls-Royce director, Customer Business Olaf Otto told Aerospace Tech Review. “I think there are numbers that are meaningful for different applications…In all the discussions that I’ve had, the majority of small planes in terms of the mission profiles seem to be feasible from about 300 watt hours per kilogram. If you look at getting an equivalent of bigger planes, people often talk about 500 watt hours per kilogram as the number that they’d really like to have.”
“It’s very important to recognize that one-size-fits-all does not work,” Rolls-Royce’s Mekhiche pointed out. “The mature technology around 160-200 watt hours per kilogram is already planting a lot of opportunities for electrification.”
Ultimately, success won’t be defined by how good the battery technology gets, but rather by how inexpensive the battery technology gets, said Pipistrel’s Tomažič. “The price per kilowatt hour is almost more important than how many kilowatts per unit of mass.”
Voltage Challenges
Another significant challenge for electrifying aircraft is solving voltage challenges associated with batteries and electric motors.
Ganzarski said voltage for his aircraft systems measures at 800 volts. “The industry wants to increase to higher voltage levels. But right now there’s no off-the-shelf equipment that’s capable of managing and handling more than 800 volts in power. When you can achieve higher voltages you can go to lower weight systems and improve efficiency.”
At Embraer, engineers are working hard to fully understand high voltage distribution in electric aircraft design.
“We’re talking about much higher voltage than we have in conventional aircraft,” said Carlos Ilario, head of Electrification for Embraer. “So we’re doing a lot of studies to understand how we can, not only design, but incorporate that in these types of vehicles in the future.”
Other Hurdles
In addition to batteries and voltage there are other important hurdles that must be overcome. Obviously, safety is a big one. Safety opens the door to public confidence and acceptance.
In general, the highest priority for engineers working on eVTOLs and electric planes is to “eliminate any single point of failure in the aircraft design,” said Eric Samson, who heads engineering at UK eVTOL developer Vertical Aerospace. They do this by “demonstrating redundancies for all primary aircraft systems, eliminating any potential for catastrophic failure and proving continued, safe flight for failure cases — such as a rotor release or bird strikes.”
For eVTOLs to gain public acceptance, communities will have to develop new infrastructure. Landing and takeoff zones with safe passenger boarding and deplaning areas will have to be established within complex urban landscapes. Also, these new aircraft will need to be integrated into existing air traffic management systems.
Everyone agrees: That will be no easy task.
With so much going on in electric aviation, it can be challenging to keep tabs on every project out there. Here’s an abbreviated timeline based on recent company announcements:
For eVTOLs to gain public acceptance, communities will have to develop new infrastructure. Landing and takeoff zones with safe passenger boarding and deplaning areas will have to be established within complex urban landscapes. Also, these new aircraft will need to be integrated into existing air traffic management systems.
Everyone agrees: That will be no easy task.
With so much going on in electric aviation, it can be challenging to keep tabs on every project out there. Here’s an abbreviated timeline based on recent company announcements:
In 2021…
The eFlyer2 is a two-seat, electric flight trainer platform currently in development by Englewood, Colorado-based Bye Aerospace. Plans call for the lithium-ion battery-powered plane to be certified by the U.S. Federal Aviation Administration as early as the end of 2021. According to its website, the aircraft is designed to cruise at 250 km/h (155 mph) with a range of around 3.5 hours.
Bye Aerospace says the eFlyer2 will hit the market just in time for a post-pandemic resurgence of the aviation industry, triggering a need for more pilots who will require new training aircraft.
In 2022…
By late 2022, the French company VoltAero plans to begin deliveries of its four-seater Cassio 330 regional hybrid-electric airplanes. Cassio 1, a Cessna 337 hybrid-electric testbed made its first flight last October 11 from the company’s base at Royan-Médis Airport in southwest France.
In 2023…
Uber says its worldwide aerial ridesharing service Uber Elevate, could launch “as soon as 2023.” It’s partnering with eight original equipment manufacturers, including Aurora Flight Sciences, Bell, Hyundai, Jaunt Air Mobility, Joby Aviation, Overair, Pipistrel Vertical Solutions and EmbraerX.
Despite Uber’s prediction, the company’s partner, EmbraerX, isn’t talking publicly about what year EmbraerX’s aerial rideshare vehicle will enter service. Concept images from EmbraerX show a futuristic 8-rotor eVTOL that carries a pilot and four passengers.
Engineering Manager Luiz Valentini and his team have been using flight simulator software to test new eVTOL designs – including new pilot control interfaces that he said would be very easy to use. The new vehicle would include fly-by-wire controls that could eventually lead to autonomous flight.
Sometime in 2023, Bell — another Uber Elevate partner — hopes to conduct the first flight of its ducted fan eVTOL dubbed Nexus 4EX. The company has said the aircraft will be “configurable in an electric or hybrid electric platform.”
2023 is also the year Germany-based Volocopter is expected to launch a commercial eVTOL air taxi called VoloCity. In fact the company is so confident that it’s already accepting passenger reservations aboard the lithium-ion battery aircraft. VoloCity is designed to carry two passengers, plus hand luggage, according to Volocopter’s website. Range: 35 kilometers (22 miles) or about 30 minutes. Maximum airspeed: 110 km/h (68 mph). The eVTOL’s giant halo of 18 rotors is its most distinctive design feature.
What about eVTOL cargo aircraft? In the second half of 2023, Pipistrel expects its Nuuva V300 autonomous, battery-powered cargo eVTOL to enter service. The Nuuva V300’s eight rotors will give it vertical electric propulsion, making it optimal for delivering cargo to remote locations without runways. Its two fixed wings and pusher propeller will allow it to fly as far as 2,500 kilometers (1,350 nm). The V300’s expected payload is up to 460 kilograms (1,014 pounds.) Cruise speed: 165-220 km/h (89-119 knots). Cruise altitude: 6,000 meters (19,700 feet).
In 2024…
A fixed-wing, tilt-rotor eVTOL called VA-1X is scheduled to enter commercial service sometime in 2024. Designed, tested and manufactured by Bristol, England-based Vertical Aerospace, the VA-1X will have a range of up to 160 kilometers (100 miles) and a cruise speed of 240 km/h (150 mph).
The aircraft’s one-pilot crew would fly four passengers from city to city as well as provide transportation within large cities, to help ease gridlock on the ground that plagues so many urban areas.
From 2025 to 2035…
By 2026, Gothenburg, Sweden-based Heart Aerospace says its ES-19 electric airliner will be certified and delivered for service. The fixed-wing design involves four battery-powered propellers that the company says will allow the plane to reach a cruise speed of 180 knots and achieve a range of 400 kilometers (250 miles). Capacity: 19 passengers.
In 2035, three zero-emission concept aircraft unveiled by Airbus last September could enter service, the airframer said. All three designs would be powered by “modified gas-turbine engines running on hydrogen,” according to Airbus. One is a turboprop designed to carry 100 passengers. The other two are a twin turbofan design and a blended-wing body design that would carry 200 passengers each, Airbus said, with a range of about 2,000 nautical miles.
Transportation Tapestry
The consensus among industry leaders is that the next 15 years could very well produce a fascinating mix of aircraft platforms with different fuel and power sources – all coming together to weave a colorful new transportation tapestry.
Some of these future powertrains will be new and exotic, while others will be more familiar.
“The turbine engine is going to continue to be the workhorse for large payloads and large aircraft in general,” said Mekhiche at Rolls-Royce Electrical.
Electric hybrid platforms will be part of the mix as well, because they offer engineers and designers a tremendous amount of additional design freedom.
“We believe that all these areas are key to making the next leap in aerospace propulsion more sustainable and more environmentally friendly,” Mekhiche said. “The electrification piece – we see this as a key technology. Everything that we’ve done and all the investment that we’ve put towards developing the technology shows that it’s feasible.”
The challenge, he said, is to continue to develop products that are not only effective, but also that make good business sense.
“We believe that we’re on a journey to get there,” said Mekhiche. “We’re seeing already, in some of the aircraft that we’re already working on, that the value proposition is definitely there, and we can make it work.”