This was the year that the “Electric VTOL Revolution” arrived in Oshkosh. It will never be the same.
By Kenneth I. Swartz
The world’s largest gathering of pilots and aviation enthusiasts takes place every year in Oshkosh, Wisconsin, where the Experimental Aircraft Association (EAA) has hosted its massive fly-in convention for 50 years.
Oshkosh has a long been associated with innovation, from experimental homebuilt aircraft and Burt Rutan’s imaginative designs to the world’s fastest, largest and most expensive civilian and military aircraft.
In the last decade, Oshkosh has also become an important meeting place for electric aviation pioneers and enthusiasts developing a spectrum of aircraft and associated technologies.
This year, the Vertical Flight Society again partnered with the Comparative Aircraft Flight Efficiency (CAFE) Foundation to co-host the annual Electric Aircraft Symposium (EAS) at the University of Wisconsin – Oshkosh on the weekend prior to EAA’s AirVenture.
The CAFE Foundation and VFS are both pioneers when it comes to advancing electric aviation. The CAFE Foundation was originally founded in 1981 to foster the development of more fuel-efficient general aviation aircraft. The Foundation hosted the world’s first Electric Aircraft Symposium in 2006 and VFS held the world’s first electric VTOL aircraft symposium in 2014 — so it makes a lot of sense for the two non-profit educational organizations to collaborate since electric conventional takeoff and landing (eCTOL) and eVTOL aircraft designs share many of the same technologies and challenges.
Thirteenth Annual Electric Aircraft Symposium
The CAFE Foundation’s 13th annual EAS, co-sponsored again by VFS, featured presentations by two dozen industry experts with strong backgrounds in aerospace technology, regulation, marketing and finance.
This year’s EAS was divided into six sessions focused on: state of the industry; emerging technologies; tiltwing and tiltrotor VTOL lessons learned; standards and certification; safety and operations; and electric aircraft development, including both eVTOL and eCTOL programs.
Three speakers represented VFS at EAS, including Executive Director Mike Hirschberg, Regional Director for the Americas and Vertiflite Senior Editor Kenneth Swartz, and former NASA Langley engineer Todd Hodges.
The message from the EAS was that the electric aviation industry has had a remarkable year, with lots of activity across the emerging industry.
Some 70 VFS corporate members are now engaged in eVTOL/urban air mobility (UAM) and the Society had nearly 200 eVTOL aircraft on its authoritative World eVTOL Aircraft Directory hosted at www.eVTOL.news.
As of the time of the conference, the Directory provided comprehensive information on 67 Vectored Thrust, 26 Lift + Cruise, 46 Wingless (Multicopter), 14 eHelos and eGyros, and 38 Hover Bikes/Flying Devices, with many of the small Personal Flying Device designs competing for the $2M GoFly Prize.
At the recent Paris Airshow, Airbus and Boeing’s Aurora Flight Science displayed new eVTOL aircraft alongside their large commercial jets, Rolls-Royce announced its acquisition of Siemen’s electric aviation unit, and Safran and Daher announced a new electric aircraft partnership.
Government support for electric aviation is also growing. Recently, Norway announced that all short-haul domestic flights (under 90 minutes) must be flown by electric-powered aircraft by 2040. This includes about 60 subsidized short-haul routes currently serving more than two dozen remote coastal communities.
And in the past 12 months, several “first movers” have ordered eCTOL aircraft for airline and flight training or committed to retrofits: Harbour Air of Vancouver, British Columbia, selected magniX electric motors to retrofit its entire fleet of 40 de Havilland Canada Beaver, Otter and Twin Otter seaplanes; Eviation announced that Cape Air is the launch customer for its all-electric, nine-seat Alice; several small airlines ordered Ampaire’s “parallel hybrid” retrofit of a Cessna 337 (with an electric pusher engine); and OSM Aviation Academy, a flight training school in Scandinavia (previously known as the SAS Flight Academy) ordered 60 Bye Aerospace eFlyer 2 trainers.
Community Air Mobility Initiative Launched
At EAS, CAFE Foundation executive director Yolanka Wulff announced the launch of the Community Air Mobility Initiative (CAMI) to “support the responsible integration of the third dimension into our daily transportation needs through education, advocacy, and community engagement.”
Wulff said that as technology and the regulatory landscape develops, the need for local advocacy and community and public education in support of UAM is becoming more acute.
She explained that, “while other organizations provide federal-level advocacy, the success of the industry will hinge on air mobility being embraced by local communities, cities, states and the general public.”
Wulff is the co-founder of CAMI with Anna M. Dietrich (formerly of Terrafugia) and they intend to provide a link to the local level, providing education and resources to the public, decision makers and the media.
“We are here to help people and communities take to the skies,” states the CAMI website (www.communityairmobility.org).
Lindbergh Innovation Forum Highlights eVTOL
Representatives of several eVTOL aircraft and propulsion developers spoke on a panel at the Charles A. and Anne Morrow Lindbergh Foundation Innovation Forum at AirVenture including moderator Eric Bartsch, CEO of VerdeGo Aero; Craig Hoover, Advanced Technology and Hybrid-Electric Pursuits Leader, GE Aviation; Bruce Holmes, Director, Alaka’i Technology; Bob LaBelle, CEO, XTI Aircraft; and Ryan Naru, Vehicle Standards Lead, Uber Elevate.
Four of the five speakers on the panel believed that batteries alone would not provide enough power for most eVTOL missions (with energy reserves), with Uber being the exception. However, all agreed that electric aircraft will be a very disruptive change to general aviation.
Bartsch said there is “not one solution for all applications” when it comes to electric power, adding that “there are a lot of ways to generate electrons,” such as batteries, hybrid electric systems and hydrogen fuel cells. He said what’s really important is that the “aircraft architecture, mission profile and powertrain architecture” are aligned.
Holmes said that Alaka’i selected lightweight hydrogen fuel cell technology for its six-propeller Skai eVTOL aircraft that was publicly unveiled in May. The company plans to fly its prototype for the first time later this year near its headquarters in Massachusetts.
Hydrogen fuel cells have been around for a while, but the main aerospace applications have been on spacecraft, including the International Space Station. A fuel cell works by releasing electrons when hydrogen and oxygen combine to form water. Three hydrogen fuel cells on Skai generate electricity, powering all onboard systems and the six quiet 100 kw electric motors.
Alaka’i plans to use hydrogen cooled to liquid form at −423.17 °F (20.28 °K or −252.87 °C) and stored in double-walled pressure tanks at 100 psi to give its eVTOL aircraft an endurance of two to four hours. (Other aerospace companies like ZeroAvia, which is testing a fuel cell on a modified Piper Matrix, plan to use hydrogen compressed to about 5,000 psi, which is common in cars made by Toyota and Honda that use high-pressure fuel cell systems).
Holmes believes the first applications for the Skai will be in rural areas, rather than urban areas, such as regions “left out of the national infrastructure.”
LaBelle said that XTI was originally going to use a mechanically driven system on its TriFan 600 VTOL business aircraft, until they realized that a hybrid-electric powerplant would provide a significant reduction in weight and cut the aircraft price in half. A 65%-scale version of the TriFan 600 assembled by Trek Aerospace is being flight tested at the Deseret UAS Center in Utah.
GE Aviation’s Hoover said that hybrid-electric systems will allow companies to push forward with electric aircraft development “while they wait for batteries to catch up.”
Holmes added that, “we are seeing a tectonic shift. Something we haven’t seen before,” where companies like Airbus and Alaka’i “are not selling an air vehicle, but they are selling an air solution” where they will be involved in the design, development, manufacturing and delivery of aviation services, as well as support services.
Naru observed that the coming wave of electric-powered aircraft will need to be maintained by mechanics with much greater knowledge of electric systems and a wide range of support issues.
Opener BlackFly Enters Production
At EAA AirVenture, Opener announced it had launched production of the single-seat BlackFly fixed-wing eVTOL with an initial batch of 100 aircraft to sell. The BlackFly program was first revealed in July 2018 after eight years of stealth development.
The aircraft is the brainchild of Canadian aeronautical engineer and inventor Marcus Leng, who hovered his prototype SkyKar Rebel ultralight eVTOL aircraft at his house in Warkworth, Ontario, on Oct. 5, 2011. Development began outside Toronto, but the Canadian company soon moved its operations to Silicon Valley, California, and took the Opener name after Larry Page and other Google executives took an active interest.
At AirVenture, Opener CEO Leng was awarded the EAA’s 2019 August Raspet Award “in recognition of his outstanding contribution to the advancement of light aircraft design. Leng innovated modern battery and motor technologies to produce BlackFly, the world’s first fixed-wing, all-electric vertical take-off and landing (eVTOL) personal ultralight aircraft.”
In addition, Opener donated one of its BlackFly V2 prototypes to the EAA Museum in Oshkosh to inspire the next generation of aviators. The aircraft was hull number 11, the first V2 that carried a passenger.
“I’d like to think that nothing about this aircraft is traditional,” said Opener’s new president Ben Diachun. “It is really a unique design.”
Diachun joined Opener this spring after 16 years at Scaled Composites where he worked — first as an engineer and later as the company president — on 16 different aircraft designs that progressed from an idea to first flight.
“I came to Opener because of a unique combination,” he explained. “Not only does the vehicle have unique technical aspects, but there is also an amazing team behind it … who innovated way back before a lot of people could see the [eVTOL] market clearly.”
As he followed the emerging eVTOL industry, Diachun saw a lot of companies jump in to the eVTOL industry “because of the converging technology” and saw public demand growing for a personal air vehicle that is simple and low cost. Opener is focusing all its efforts today on “direct sales of a personal air vehicle,” said Diachun. “This is a vehicle we’d like to sell to everyone,” so they can commute to work, escape the city or just explore the countryside.
BlackFly is recognized by the US Federal Aviation Administration (FAA) as a Part 103 Ultralight Vehicle — which restricts the takeoff weight to 254 lb (115 kg), plus allowance for floats — and by Transport Canada as a Basic Ultralight Aircraft.
The aircraft can easily take off and land on small areas and travel distances up to 35 miles (56 km) — restricted to 25 miles (40 km) in the US under Part 103 — at speeds up to 75 mph (restricted to 62 mph/100 km/h in the US). The winged aircraft is powered by eight electric motors and cruises like a staggered biplane in forward flight.
Since 2014, more than two dozen BlackFly test aircraft have cumulatively flown more than 23,000 miles (37,000 km) during more than 2,300 flights. That includes 11,000 miles (17,700 km) and 900 flights on the preproduction V3 model since it was first displayed at AirVenture in 2018.
For the past five years, Opener has operated a year-round flight test site over 6,000 acres (2,500 hA) of canola fields somewhere in the prairie province of Saskatchewan. This is where several BlackFly V3 models are being autonomously flown to test a wide range of hardware and software faults to ensure safety before manned flights begin. This was the same approach taken before piloted flights of the V2 version began in March 2018.
“We refined the design over time using a building block approach. The initial vehicle took off and landed vertically, then we built a vehicle to focus on the transition. Then we built a series of vehicles focusing on the control system. Which then led to our [pre-production] vehicle number two [V2], which was a combination of all of that.”
“Safety is the number one driving thing behind everything we do,” said Diachun. “It has to be a safe vehicle if we want everyone to operate it.”
The V3 version has upgraded flight control firmware and software, better aerodynamics, and it is designed for streamlined manufacturing. The aircraft has a triple-redundant flight control system and it’s capable of safely flying with two motors out on one side or quadrant.
“On the V3 version, we have re-spun the avionics and control systems to use all of the lessons we have learned out of the testing and also introduced structural changes that made the structure more robust and safer and easier to manufacture.”
The BlackFly V3 is also being equipped with a whole aircraft ballistic parachute as an additional safety feature. Testing the deployment of the system and the vehicle recovery is a future task on the test program.
The goal of the V3 test flight program today is to “validate that the design performs as expected. A lot of the testing we are doing now is on the ‘off-nominal’ cases and that is how we ensure safety: really going to every corner of the envelope and understand what happens in that off-nominal situation. How do the systems perform? How does the airframe perform? And are we getting the result that we are expecting?”
“Right now, we are going back … it’s regression testing in some sense … to validate all those changes. To make sure we have got the results we want from those upgrades. That we have a robust system … to enter the marketspace that will be safe for everyone …because we’d like anyone to be able to fly this … autonomously, commercially, in an urban area and in a rural area.”
Opener is putting all the technology and performance into the BlackFly V3 today, so “as the regulatory environment allows that kind of operation, we will be ready to go.” Diachun is also excited that regulators are willing to discuss how “we could take an aircraft like this from an ultralight to potentially a type certificate.”
BlackFlyOpener is a vertically integrated company, with many of the BlackFly features developed in-house or sourced from a small group of suppliers. The composite airframe is hand-built using molds and traditional techniques. It has a very modular design, where each propulsion unit can easily be removed and replaced. In addition, the wings can be detached in 30 minutes so the aircraft can be moved by trailer or stored.
Diachun said that the aircraft’s high level of automation means that pilots and non-pilots can learn to fly the aircraft after a one-day course. No formal licensing or special skills are required to fly an ultralight class aircraft in the US, but pilots of basic ultralight aircraft in Canada require a pilot’s certificate.
The company is waiting for the development flight testing to be complete before it starts taking orders. Opener has stated that the aircraft will be priced “about the same as an SUV,” although this covers a fairly wide price range.
Opener is hiring in all disciplines, including engineering, business development and fabrication. About two-thirds of the Silicon Valley company’s employees are Canadians recruited by Marcus Leng from universities in Ontario and other provinces.
Diachun previously led development of a wide variety of innovative experimental aircraft as president of Scaled Composites, which was founded by Burt Rutan and recently developed the SpaceShipOne and SpaceShipTwo air-launched suborbital spaceplanes, as well as the late Paul Allen’s Stratolaunch — the world’s largest composite airplane designed to air launch systems to orbit.
VerdeGo Aero Partners with Continental Motors
At AirVenture, Continental Aerospace Technologies announced it was teaming with VerdeGo Aero to develop hybrid-electric propulsion systems with Continental’s Jet-A fueled piston engines. The new strategic partnership will see VerdeGo use Continental’s FAA-certified diesel engines as part of its Integrated Distributed Electric Propulsion (IDEP) system to power eVTOL aircraft with gross weights up to 7,500 lb (3.4 metric tons).
The IDEP system features “integrated hardware and software to provide energy, redundancy, power distribution, propulsion, and attitude control for a wide array of vertical takeoff (VTOL) and distributed electric propulsion (DEP) aircraft platforms.”
VerdeGo Aero was founded two years ago by Erik Lindbergh, grandson of famed aviators Charles and Anne Morrow Lindbergh, to develop “a safe, clean and quiet hybrid-electric vertical takeoff and landing (eVTOL) aircraft that can fly piloted or autonomously.”
The new company, with Lindbergh as president, tapped electric aircraft industry pioneers Dr. Pat Anderson, as Chief Technology Officer (CTO); and Eric Bartsch, originally as Chief Operating Officer (COO) but Chief Executive Officer (CEO) since June. Each principal has more than a decade of past experience with green aviation.
VerdeGo’s first-generation IDEP systems will be sized for 2-3 seat (200-350 hp/150-260 kW) and 5-7 seat (500-800 hp/375-600 kW) aircraft and contain hybrid generators to enable eVTOL “to be viable with technologies available today.” As battery technologies mature, VerdeGo’s modular IDEP systems will also be configured with rechargeable battery packs providing primary power.
Continental was acquired in 2011 by Technify Motors (USA) Ltd, a subsidiary of China’s AVIC International. In 2013, Technify also acquired the portfolio of diesel aircraft engines of bankrupt Thielert Aircraft of Germany — the first Jet-A kerosene piston aircraft engines certified by the European Aviation Safety Agency (EASA) and the FAA in 2002–2003.
“I see eVTOL as the most exciting time there has ever been in my lifetime and … see a lot of capital flowing in. It’s extremely exciting and the experimental [projects] show us what’s possible,” said VerdeGo founder Lindbergh.
Lindbergh noted that eVTOL aircraft need to be energy rich to be commercially viable, and for the next 10 years, hybrid-electric will provide enough power for eVTOL to perform their missions so “when batteries come along slowly we can replace those systems and [use] batteries to be all-electric.”
Lindbergh explained that some of the advantages of a hybrid system using a Jet-A piston engine include low noise (using a muffler), low fuel consumption and low cost, with the weight of an entire powertrain (engine, generator, batteries and motors) weighing only slightly more than a turbine-powered hybrid-electric system.
Lindbergh said that a pair of jet-fuel-powered hybrid-electric engines installed in an eVTOL aircraft would also provide the additional level of redundancy required for UAM missions at relatively low cost.
Diesel aircraft engines have a higher compression ratio, which results in about 30% lower fuel consumption. Kerosene-based jet fuel is also more widely available and less expensive than traditional aviation gasoline (avgas). One disadvantage of a diesel engine is that they are usually heavier because a higher compression-ratio design requires a larger and stronger engine block.
Continental currently markets the 135 hp (99 kW) CD-135, 155 hp (114 kW) CD-155, and 300 hp (224 kW) CD-300, which are all equipped with an electronic engine management Full Authority Digital Engine Control (FADEC). Altogether, the more than 3,500 Continental diesel engines (including Thielert models) operated in general aviation aircraft have, to date, successfully flown more than 3.5 million hours.
Most of the original Thielert engines were installed on the Diamond DA40TDI and DA42 light aircraft, but after the Thielert insolvency in 2008, Diamond switched to its proprietary Austro Engine to power the DA40 and DA42. However, the relationship was rekindled earlier this year when Diamond selected the new fuel-efficient Continental CD-300 to power its new large-cabin DA50 light aircraft.
VerdeGo was founded as an original equipment manufacturer (OEM) for developing its two-seat, hybrid-electric PAT200 eVTOL and a larger four- to six-passenger eVTOL aircraft. The PAT200 concept has eight electric propulsion pods on a dual-tiltwing platform — the propellers on the rear wing are pushers that tilt down for vertical flight, while the propellers on the canard are tractors, tilting up for VTOL mode.
In August 2018, VerdeGo made a strategic pivot to become a propulsion provider when it realized there was a necessity for technology companies operating behind the scenes that could enable eVTOL makers to achieve their goals, Bartsch explained. “Our role in the market is to provide the propulsion hardware to this new market segment.”
“Hybrid-electric technology is accessible now … and is a proxy for a battery,” he continued. “It allows you to design the right aircraft for the right market right now with a hybrid-electric system,” with an “evolution into battery electric when that is ready.”
Bartsch believes that flights of pure-electric aircraft will be limited to very short segments over the next 10 years, once you consider a regulatory requirement for 30 minutes of reserve power.
“Off-the-shelf aviation propulsion engines are not great for hybrid-electric power generation,” said Bartsch. “They have been optimized to spin a propeller. We want to spin a generator, so they have to behave different.”
Continental engineers will work with VerdeGo to optimize their engines for hybrid-electric use.
Luminati Exhibits eVTOL Aircraft
Luminati Aerospace CEO and CTO Daniel Preston brought two eVTOL aircraft designs to AirVenture incorporating co-axial rotor and transmission technology developed by Gyrodyne Company of America. Preston said the designs are suitable for 1-2- and 5-6-seat capacity eVTOL helicopters.
Last year, Luminati displayed a historic single-seat Gyrodyne XRON, powered by a 72 hp (54 kW) Porsche YO-95-6 four-cylinder piston engine. Luminati then converted the aircraft into an eVTOL at its facilities in Little Falls, New York, about 70 miles (115 km) northwest of Albany. It was displayed at the VFS Forum 75 in Philadelphia in May and again this year at AirVenture.
The aircraft now features a 125 hp (93 kW) electric motor (capable of 160 hp/119 kW for short periods) developed by Oved Zucker of Polarix Corporation “that has a very high power-to-weight ratio … producing 20 hp/lb [33 kW/kg]” and is powered by 3,800 next-generation Sony rechargeable lithium ion 18650 cells packed beneath the helicopter in an air-cooled compartment. The gearbox on the helicopter was also modified to accept the higher torque.
Preston wants to set a Fédération Aéronautique Internationale (FAI) endurance record for VTOL aircraft with the electric-powered XRON. “Endurance is the primary record we are looking to beat. And for the record attempt, we will be using an even lighter battery pack based on pouches. It doesn’t have the added weight of the can of the 18650 cells. The idea is to use smaller pouches instead.”
The “everyday” battery pack will give the XRON an endurance of 45 minutes in a hover with a 180-lb (82-kg) pilot, and greater endurance in forward flight. Building a power source with pouches will cost about $300,000 more to construct. Preston said the company has also experimented with lithium-sulfur batteries, “but there are some issues with the number of charges they can accept.”
The second rotorcraft on display was a tubular steel frame with a larger Gyrodyne QH-50 transmission, rotor head, blades and an electric motor installed.
A total of 377 Gyrodyne model QH-50D remotely-controlled unmanned aerial vehicles (UAVs) were delivered to the US Navy by 1969 as the Drone Anti-Submarine Helicopter (DASH) weapon system. The QH-50 family flew more than 160,000 unmanned flight hours until the last was retired by the US Army from the White Sands Missile Range in 2006.
Preston said that Luminati bought the rights to the Gyrodyne helicopter system as well as the manufacturing rights to Rotor Flight Dynamics, Inc.’s Dragon Wings rotor blades used on many different gyroplanes and some experimental helicopters.
“We’d like to generate [helicopter] models for consumer and commercial use,” said Preston, adding that Luminati plans to make two different Gyrodyne coaxial rotor systems based on the 1950s XRON and QH-50 designs. The Luminati designs will be suitable for 1-2-seat and 6-seat rotorcraft, respectively. In addition to new single- and twin-turbine applications, Luminati also plans to develop a hybrid-electric rotorcraft around the QH-50 rotor system.
Innovations for UAM
From the smallest startups to the largest OEM, this was the year that electric VTOL was on display at AirVenture with the widest range of products ever. In addition to the aircraft discussed above, EAA also had an Innovations Showcase and a discussion forum sponsored by UAM website TransportUP. As a result, many of the GoFly teams were able to display their concepts, including Aeroxo, Athena Aero, Electric Jet, Trek Aerospace and ZEVA. Other eVTOL innovators — including Assen Aeronautics, AutoFlightX, Beta Technologies, EmbraerX and Airbus’s Urban Air Mobility business unit — also had booths in the pavilions.
Airbus also displayed its Vahana tandem tiltwing eVTOL at its AirVenture pavilion for the first time. This, the second aircraft (N302VX), was on its way back from its public debut at the Paris Air Show in June (see “Paris Air Show 2019: European Vertical Sensation,” pg. 34). Befuddled passersby gawked and tried to make sense of the tandem wings and all the propellers.
With each passing year, the “Electric VTOL Revolution” expands to capture the imagination of more of the aviation community, the public and “smart city” urban planners. From single-seat personal flying devices and eVTOL ultralights, this year’s AirVenture was another showcase for UAM innovations.
About the Author
Ken Swartz runs aerospace marketing communications agency Aeromedia Communications in Toronto, Canada. He specializes in contract public relations, freelance writing, and social media marketing for the aviation and aerospace industry. He has reported on the helicopter industry for 40 years. In 2010, he received the Helicopter Association International’s “Communicator of the Year” award. He can be reached at firstname.lastname@example.org.
More photos are available in the VFS Vertical Flight Photo Gallery at www.vtol.org/gallery.