Big Events and Numbers for Bye Aerospace

Bye Aerospace has four big current projects, with the Sunflyer 2 at the top of the development and sales curve.  Teaming with Siemens, Bye Aerospace is now flying Sunflyer 2 with one of their 57 pound SP70D motors producing a 90 kilowatt peak rating (120 HP), and continuous power up to 70kW (94 HP).

Bye anticipates that Sunflyer 2 will be, “the first FAA-certified, practical, all-electric airplane to serve the flight training and general aviation markets.”  George Bye, the company’s founder and CEO has been working with Agency for several years on devising rules for electric aircraft certification.

The need for 790,000 new pilots in the next few decades will drive the need for training aircraft.  An aging fleet with an average age of 48 years for the Pipers and Cessnas on flight school tarmacs requires a newer, more modern series of training planes to replace them.

Sunflyer 2 on February 8, 2019 during first test flight with a Siemens motor

Sunflyer’s impressive sales numbers (a recent order from the Aspen Flying Club for 30 Sunflyer 2s raised the total to over 130 worldwide) hit 220 when including Sunflyer 4’s numbers.  Its operating costs – $14.00 per hour compared to a Cessna 172’s $88.31 – benefit from lack of fuel costs -$44.00 per hour for the 172 vs. $3.00 per hour to recharge the Sunflyer for another hour aloft. Lower maintenance costs come from the lower inspections bills ($22.40 for the Cessna – $2.40 for the Sunflyer), and maintenance charges (oil changes, ignition and accessory maintenance add $11.91 per hour to the Cessna’s total).   The only “wash” between the two trainers would come from $10.00 per hour replacement cost for the Cessna’s engine vs. the $8.00 per hour replacement cost for the Sunflyer’s batteries.  We hope reductions in operating costs get passed on to new pilots, encouraging the growth of a new customer base.

The maximum rate of climb of the aircraft is 1,150fpm, while the normal speed varies between 55 knots (63.25 mph) and 120 knots (138 mph) .  The aircraft has a flight endurance of 3.5 hours.

The two-seater variant has a wingspan of 11.58m (37.98 feet), wing area of 129feet² (12meters²), cabin width of 1.16 meters (45.65 inches) and glide ratio of 18.5. It has an empty weight of 1,460 pounds (662 kg), while the gross weight of the aircraft is 1,900 pounds (862 kg).

(left-to-right) Olaf Otto, Siemens Head-of eAircraft sales and business development-and George Bye, Bye Aerospace CEO.  Photo courtesy Bye Aerospace

Subaru Invests in Bye’s Future

In a related story, Subaru-SBI, an investment arm of the automobile manufacturer, provided investment funding to Bye Aerospace to help facilitate the certification process for the Sunflyer family of airplanes.

Bye Aerospace reports, “George E. Bye, Founder and CEO of Bye Aerospace, expressed his gratitude for the investment. ‘On behalf of our team, my sincere thanks to the SUBARU-SBI Innovation Fund for their vision, their passion for our industry and their belief in electric propulsion,’ he said. ‘This is Bye Aerospace’s largest individual investment to date.’

“Itaru Ueda, Manager of the SUBARU-SBI Innovation Fund, said, ‘We believe Sun Flyer 2 will be the first electric airplane to receive FAR Part 23 type certification. Electric aircraft are receiving lots of attention, and we expect the future of small electric airplanes to be led by Bye Aerospace.’”

As Tine Tomazic of Pipistrel has reminded us, “Progress moves at the speed of cash.”  With orders coming in and funding from overseas, Sunflyer 2 will be a good competitor for Pipistrel’s training plans.  The future seems to be coming quickly and with more hope for General Aviation than we’ve seen in a long time.


Calin Gologan, Scylax and China

Everything in the world seems to require massive or distributed investment even for simple projects.  Low-budget movies have multiple production companies and different car companies share the same engine or drive train.  Calin Gologan and PC Aero have expanded their offerings over the last decade, and have also expanded their partnerships.  Now, to make his twin-motored commuter liner a reality, he has partnered with a Chinese investor to produce the Scylax E6 and E10 aircraft.

Although the E6 was, “Announced at Friedrichshafen’s Aero Expo and displayed (at least in model form) at the 2013 Paris Air Show, the Elektro E6 is the technology platform for a future, all electric transport aircraft.”  Today’s SCYLAX E6 remains visibly the same as the 2013 version, a full carbon-composite structure with solar cells on the wing and able to carry a payload of 480 kilograms (1,065 pounds).

Funded by EADCO GmbH in cooperation with PC-Aero GmbH, Elecktrosky GmbH promoted the E6 as, “The technology platform for the future commercial e-aviation.”  The team hoped to build a Proof of Concept vehicle in less than three years and achieve CS23 Certification (equivalent to FAR Part 23) in 10 years.

As promised in 2013, “The Elektro E6 will include all systems of a normal commercial aircraft in the final version, including retractable landing gear, anti-ice system, cabin pressure and air conditioning, according to the company plan.”

Now a Chinese private company China Blue Airlines has added a 75 million euro stake in the project.  The deal, formalized in September at the Bavarian Ministry of Economic Affairs, gives China Blue full ownership of the Chinese market for the already-flying E1 and E2 solar-powered machines.  This might mean large-scale production of the single- and two-seat machines, much as Pipistrel’s Chinese manufacturing plan.

The partners should complete feasibility studies in 2020, with certification finished by 2022, leading to production.

Rosario de Luca, managing director of  SCYLAX GmbH (and of EADCO GmbH), and with Calin Gologan, explains, “’We want to start series production in 2024,’ of the E6 and E10, following the setup of manufacturing and testing of the new models.  The E1 and E2 are well established.  German production will continue, but no German firms have expressed interest in the twin-motor craft.

From 2024, the E10 machine is expected to go into mass production.© Scylax

The partners promise big things, indeed.  “With the investment, the company intends to develop the world’s first commercial electric aircraft to series maturity. And together with the Chinese partner, the world’s largest research, development and production center for solar and electric aircraft is to be set up in China.”

The six and ten-passenger craft are expected to cruise at 360 kilometers per hour (223 mph) over their 400 kilometer (248 mile) range.  A sign of their projected good performance, takeoff run is claimed to be 300 meters (984 feet).  This should allow use of small regional airports.

Airliners.doc reports, “In addition, both models are modular. Thus, the machines can be used with little effort and low cost as a cargo or passenger machine. Also conceivable is a special military version. The batteries can be charged within twenty minutes. The price for the E6 version is the manufacturer with around one million euros. The larger version is almost twice as expensive at 1.7 million euros.”

We wish the partnership and the project all the best.  These would be very nice rides indeed.


Two Different Carbon Batteries

With lithium-ion batteries seeming to have topped out in their capabilities, battery researchers are looking at new ways of storing energy.  Zap&Go in England and Graphenano in Spain are exploiting a more common element  to good effect, crafting carbon batteries that charge quickly and last thousands of charge-discharge cycles.  Both attack their goals in very different ways.

Zap&Go Carbon-ion Battery

According to, the Oxford-based organization Zap&Go has created and delivered a carbon-particle battery consolidating the superfast charging capacities of a supercapacitor to gain rapid charging and long cycle life.  Unfortunately, as far as electric vehicles go, it’s not quite ready for prime time.  The good news is that it’s on a well-structured timeline that will bring it to the vehicular world in the next few years.

Auto Economic Times of India reports that Zap & Go follows the path many others with new technology often go down.  “’Today it’s a developing technology, so it’s not as good,’ Zap&Go’s chief executive Stephen Voller told Reuters on Monday. ‘But our plan over the next few years is to meet or exceed lithium-ion.’”

Combining conventional battery with supercapacitor technology, Zap&Go uses nanocarbon materials to cut vehicle charging times to five minutes, roughly equivalent to refill times for gasoline vehicles.  The company’s Carbon-ion or C-ion battery is based on years of research at the University of Oxford.  Voller notes the battery now in its third generation, does not need rare earth minerals or toxic chemicals like cobalt.  Instead it sources its carbon from coconut shells, although Voller anticipates that source to change over time as demand grows.

Zap & Go’s batteries are low voltage at this point, but aimed to greater output in the near (or not-so-near) future.

Voller claims the new battery can offer longevity: “It would be a 30-years useful life or 30-year warranty.”  Because the C-ion relies on an electrostatic, rather than an electrochemical, reaction, no degradation over thousands of hours of use has been observed.

“Today, Zap&Go is in production of its third generation units that operate at 3.4 volts, according to Voller. ‘These cells are designed for grid storage, not electric vehicles,’ so don’t get too excited about seeing them in electric vehicles anytime soon. EV batteries are definitely in the longer term outlook for Zap&Go, and the technological glide path is clear. ‘We are developing our generation 4, which is operating at 4 volts.’”

Like the traditional disclaimer that the new miracle battery shows great promise, but it five years from commercialization, the company says its fourth generation cells will be followed by “gen 5 and gen 6” batteries that will be suitable for vehicles – in about 2025.

The cells can be made in the same factories and on the same production lines as existing lithium ion batteries. But the firm might consider pushing the performance limits more quickly, since competitors are growing in number and competence.

With applications such as grid storage and recharging stations a realistic use now, we can only anticipate Zap&Go’s next moves.  We would love to see more detailed specifications of what we can realistically expect for EVs in the meantime.

Grabat’s Indestructible Cells

While Zap&Go may be a little vague on detailed specifications for now, Grabat, a Spanish graphene provider and battery maker finds a different path to using carbon to store energy.  Their pouch cell in this video seems nearly indestructible, and helpfully, non-flammable despite some “creative” destruction.  This demonstration, similar to tests on Zap&Go cells, should give electric vehicle users great confidence.

Partnered recently with Abtery, a Swedish electric drive train design firm, executives from both firms repeat tests from the first video, demonstrating extreme faith in the battery.  Bare handed, other than protective gloves (probably to protect the cells), Martin Martinez, president of Grabat, shows the safety and reliability of the pouch cell.

Observers include Jose A. Martinez, Grabat Vice President and Inaki Fernandex from Aspid Cars.   Aspid makes supercars, and this shows a possible future for this performance manufacturer.

Elise, a Battery-Powered Electric Airplane

Abtery and Grabat are part of a consortium developing a futuristic small transport aircraft, probably slated for low-altitude, high-speed flight based on the large windows that would not take kindly to pressurization.

Abtery is part of a Swedish consortium to design and build Elise, a short-haul cruiser

The project explains, “The name Elise is an acronym for “Elektrisk Lufttransport i Sverige” (Electric Aviation in Sweden). The project is funded by the Swedish innovation agency Vinnova.

“Elise are building an electric aircraft in Sweden. It is collaborative effort  between Chalmers University of Technology, KTH – Royal Institute of Technology, Linköping University, Luleå University of Technology, Uppsala University, the Civil Aviation Administration and RISE Viktoria research institute with the aerospace industry and other actors.”

Part of an even larger aspirational organization, Elise is a small part of the group’s desire to enhance climate and the environment while reducing social issues such as poverty and hunger.  This presentation shows part of the consortium’s recent symposium which explains where Elise fits in the overall scheme of electric aviation.  We will have a more detailed write-up on Elise soon.



Ethiad Airways made the first commercial flight on fuel made from plants grown in saltwater by Khalifa University.  Burning jet fuel made from halophyte plants grown in salt water and fertilized by the shrimp and fish living in the salt water enabled a flight from Abu Dhabi to Amsterdam on January 16.  It was the first flight on pure biofuels, even though commercial airlines have made over  160,000 flights on blended fuels since 2011.

The first biofuel flight’s crew in front of their Boeing 787-300

Dennis Bushnell Predicted This

Chief Scientist at NASA Langley Dennis Bushnell shared information on halophytes, plants that grow in salt water.  He presented such ideas at a symposium your editor attended six years ago, and his vision is now being realized.  He points out that 70 percent of all water in the world has a high saline content and over 40 percent of all lands are arid and cannot sustain conventional agriculture. You can see a slide show of his presentation on halophytes here.

An Encompassing Project in the UAE

The Seawater Energy and Agriculture System (SEAS) is a synergistic industrial platform that supports the aviation sector, the oil and gas industry, food production and the creation of a new agricultural alternative in the UAE.

Boeing’s work with MASDAR University created what seems an amazingly productive farm

Considering groundbreaking for the site that combines aquaculture and halophyte oil plant growth took place in June, 2015, progress has been rapid.  The site, designed with technical support from CH2M-HILL, was completed before the end of that year, It has been producing seafood and biofuels ever since.

Dr. Ahmad Belhoul, CEO of Masdar, explained, “This innovative research is tackling the challenge of harmoniously producing food and fuel in water- and arable land-constrained regions.  The project is also a reflection of Masdar City’s ecosystem that enables public and private partners to coalesce and advance sustainable solutions that have social and economic impact. This type of co-innovation is how we re-imagine what’s possible and take bold ideas to commercial reality.”

All this activity is overseen by the Sustainable Bioenergy Research Consortium (SBRC), a non-profit entity established by Masdar Institute that is part of Khalifa University of Science and Technology.

The Fuel-Making, Fish-Growing Process

Sustainable fuel for the flight was derived from oil in Salicornia plants, which were grown on the two-hectare SEAS farm in Masdar City. SEAS is the world’s first desert ecosystem designed to produce fuel and food in saltwater. Fish and shrimp raised at the facility provide nutrients for the plants as well as contribute to the UAE’s food production.

Dr Thani bin Ahmed Al Zeyoudi, Minister of Climate Change and Environment, sees a win-win outcome to this activity.  “Deep decarbonization of energy-intensive industries has a ripple effect on food security and climate action. Clean, alternative aviation fuels are an innovative and sustainable solution to significantly reducing harmful carbon emissions. The UAE is proud to be a pioneer in this domain.”

His thoughts are echoed by the Minister of State for Food Security, Mariam bint Mohammed Saeed Hareb Al Mheiri.  “This proof of concept is a ground-breaking development that addresses the challenges of energy, water and food security – three elements that are inextricably linked and which form a nexus, meaning that actions in any one area have an impact in the others. What is particularly exciting about the SEAS is that it is an initiative that supports multiple platforms; aviation, oil and gas and agriculture. It is an important specialized initiative under the aquaculture umbrella, with the UAE recognizing that this sector represents one of the best uses of what is the region’s most precious resource and has consequently established its aquaculture sector with an investment of more than AED 100 million to develop hatcheries and fish farms.”

Abu Dhabi National Oil Company (ADNOC) Refining uses UOP-Honeywell’s Ecorefining technology to take the raw Salicornia pressings to “stringent jet fuel standards.”   Abu Dhabi Vegetable Oil Company assisted in the pre-treatment phases.

Operated by the SBRC, the SEAS pilot facility became operational in March 2016, a year after ground-breaking.  Only two hectares (4.92 acres) produced all the product for this first pure Salicornia oil for the Abu Dhabi to Amsterdam flight.  The system will expand to 200 hectares (492 acres) in the next few years.

The SBRC was founded by the Masdar Institute of Science and Technology, Etihad Airways, The Boeing Company, and Honeywell-UOP. Since then Safran, GE, and the Abu Dhabi Oil Refining Company (Takreer) and Bauer have joined.

This rapid expansion of agriculturally-derived fuel has several features that give it great credibility.  In this case, it uses plants grown in otherwise hostile conditions.  It produces food for human consumption while growing plants that provide jet fuel.  Its aviation products burn cleaner than fossil-fuel equivalents.  Let’s hope for more such developments in the near future.


Making Structural Batteries More Sinewy

Multitudes of researchers have exercised their mental muscles trying to make man-made products mimic naturally-occurring structures.  According to University of Michigan researchers, the cartilage in your knees might provide the inspiration for a “structural battery” prototype that would be durable and easy to shape.

This blog has long promoted the idea of structural batteries, energy storage systems that could double as strengthening elements in the aircraft shell.  Storing energy in car bumpers or airplane wings has some risk elements.  What will happen to a battery cracked by collisions on the ground or excessive loads in the air, for instance.  Nicking or puncturing existing batteries can cause flaming catastrophes.

As U of M researchers note, “[Structural batteries] been a long-term goal for researchers and industry because they could reduce weight and extend range. But structural batteries have so far been heavy, short-lived or unsafe.  The school’s tests, described in ACS Nano, ended up with damage resistant, rechargeable zinc batteries with a “cartilage-like” electrolyte.  According to their paper, they replaced the top casing on several commercial drones with their structural batteries.  “The prototype cells can run for more than 100 cycles at 90 percent capacity, and withstand hard impacts and even stabbing without losing voltage or starting a fire.”

Research leader Nicholas Kotov, Professor of Engineering at the Joseph B. and Florence V. Cejka, explains, “A battery that is also a structural component has to be light, strong, safe and have high capacity. Unfortunately, these requirements are often mutually exclusive.”

Ahmet Emrehan Emre, a biomedical engineering PhD candidate, casts a manganese oxide slurry onto a sheet of aluminum foil to serve as the cathode of a prototype structural battery in the University of Michigan North Campus Research Complex in Ann Arbor, MI on December 21, 2018.

Researchers “sidestep” these problems by using zinc and branched nanofibers that resemble the collagen fibers of cartilage.”  They form a membrane with the material that resists dendrite puncturing.

Kotov explained, “Nature does not have zinc batteries, but it had to solve a similar problem.  Cartilage turned out to be a perfect prototype for an ion-transporting material in batteries. It has amazing mechanics, and it serves us for a very long time compared to how thin it is. The same qualities are needed from solid electrolytes separating cathodes and anodes in batteries.”

The mechanical strength and durability of cartilage with the ability to let water, nutrients and other materials move through it are nearly identical to those of a good solid electrolyte, which has to resist damage from dendrites while also letting ions flow from one electrode to the other.

Kotov’s team’s membranes shuttle zinc ions between the electrodes, and also stop zinc’s piercing dendrites. Like cartilage, the membranes are composed of ultrastrong nanofibers (taking the place of collagen) interwoven with a softer ion-friendly material (polyethylene oxide and zinc salt).

Note corrugated form of structural battery. This adds stiffness and area for additional interactions between electrolyte and electrodes

U of M reports, “To make working cells, the team paired the zinc electrodes with manganese oxide—the combination found in standard alkaline batteries. But in the rechargeable batteries, the cartilage-like membrane replaces the standard separator and alkaline electrolyte. As secondary batteries on drones, the zinc cells can extend the flight time by 5 to 25 percent—depending on the battery size, mass of the drone and flight conditions.”

To demonstrate their batteries are safe, the team deliberately cut and stabbed their cells.  The batteries did not smoke or ignite and continued to produce their design voltage despite the damage.

Because the zinc batteries are unable to charge and discharge as quickly as lithium cells, they are used as secondary or backup batteries. Kotov and his team research potentially better electrodes that are quicker charging and longer lasting.

The research was supported by the Air Force Office of Scientific Research and National Science Foundation. Kotov teaches in the Department of Chemical Engineering. He is also a professor of materials science and engineering, and macromolecular science and engineering.

Work was supported by the Harbin Institute of Technology and the Michigan Institute for Translational Nanotechnology (MITRAN), in Ypsilanti, Michigan

Researchers include Mingqiang Wang, Ahmet Emre, Siuon TungAlycia GerberDandan WangYudong HuangVolkan Cecen, and Nicholas A. Kotov. 


Pipistrel, Honeywell Sign MOU

The fun part of writing this blog is receiving news of hopeful aspirations and plans for a thriving future. Taja Boscarol, one of the founders of Pipistrel, shared such news this week. “It is my greatest pleasure and honor to announce that Pipistrel and Honeywell signed an MOU(Memo of Understanding) regarding collaboration on aircraft technologies for urban air mobility.”

The Slovenian/American joint venture headlined its press release, “PIPISTREL AND HONEYWELL COLLABORATE ON AIRCRAFT TECHNOLOGIES FOR URBAN AIR MOBILITY,” with the multi-faceted secondary headline, “Pipistrel and Honeywell combine aerospace expertise to address the technical, regulatory and business challenges of the emerging on-demand mobility market.”

Carl Esposito, president, Honeywell Electronic Solutions. shakes hands over copies of MOU with Pipistrel CEO Ivo Boscarol

 eVTOL News lists over 140 electric vertical takeoff and landing aircraft on its web site.  Early in the 20th century, there were thousands of automobile manufacturers.  Such high-end products with their attendant development and manufacturing costs can’t be maintained by all the competitors, especially when market winners survive by growing in efficiency and productivity to make desirable products at competitive prices.

Unfortunately for those companies which cannot meet the incredible demands of designing a viable aircraft, finding ways to manufacture it with the lowest parts count and most easily fabricated and assembled components, and then integrating the base assembly with communications and flight instrumentation, economic factors might doom even excellent products.

Pipistrel revealed this plan view of their eVTOL over a year ago, and will release more details soon

Companies increasingly need to affiliate with one another to bring products to market.  Notice the number of production company names taking up the first moments of the next motion picture you see.  Costs and risks that don’t correlate can make even an award-winning film a box-office flop.  Car companies are sharing power trains because meeting international emissions standards is too expensive for even a major manufacturer to tackle itself.

Boeing has recently brought in Aurora Flight Dynamics, a successful firm in its own right, because diverting funds from it major commercial and military products to develop a new line of urban air mobility products would be a stretch – even for Boeing.  For perhaps the same reasons, according their mutual press release, “Pipistrel and Honeywell (NYSE: HON) have signed a memorandum of understanding that will bring both companies together on the exploration and development of solutions for the urban air mobility market. As part of their collective effort, the companies will work together to integrate Honeywell avionics, navigation, flight control systems connectivity, and other beneficial products and services onto a future Pipistrel vertical takeoff and landing air vehicle to support fully autonomous operations in the future.”

We have had, up to now, only a plan view of the future Pipistrel VTOL, with scant detail otherwise. Watch this 2017 Uber Elevate video from about the 42-minute mark to the 53-minute mark for R&D chief Tine Tomazic’s address.  He teases what the new announcement gives a bit more of a glimpse.

Pipistrel CEO Ivo Boscarol at the 2017 Elevate Summit gave a great history of Pipistrel, two years before allying with Honeywell.

He explains the rationale for the MOU.  “This is the beginning of a long-term relationship to collectively pursue the future of urban air mobility,  “Honeywell’s expertise in        integrated avionics and flight control systems, systems integration, certification and manufacturing, combined with our capabilities in designing and developing advanced light aircraft, makes us the perfect pairing to advance the urban air mobility market. Pipistrel was chosen to be one of Uber’s vehicle development partners for their urban mobility solution, and our VTOL features next generation propulsion technology for achieving embedded lift. We have the concept which unlocks cost-attractive eVTOL opportunity by addressing efficiency and noise hurdles in vehicle lift, hover, and cruise stages of flight.”

Showing under-wing lift fans, rendering has tractor propeller where earlier plan view had pusher propeller

Honeywell’s century of experience pioneering aircraft technologies “ has positioned Honeywell to effectively collaborate with Pipistrel on defining a future for the emerging urban air mobility space.”

Carl Esposito, president, Honeywell Electronic Solutions adds, “The urban air mobility market is a challenging space, but one that Honeywell is well positioned to support and grow.  Companies looking to make breakthroughs in urban air mobility face a wide range of technical, safety, certification and business challenges that come with developing a new mode of travel in an already very dense air traffic environment. An understanding of the aerospace complexities and legacy of innovative technologies can make all the difference in addressing this emerging market. Pipistrel is a well-known leader in the light-aircraft space, and this is an excellent opportunity to support its vision of a future vertical takeoff and landing aircraft with our industry-leading avionics, flight control systems, and other potential products and services.”

Two leading companies banding together in a new and complex field should have a good chance at succeeding because of their combined expertise.  Certainly their success will help determine what the future UAM market will look like.


Sunseeker Duo – The Uniquely Big Picture

Unique People

Eric Raymond was the first person to fly across the United States on solar power in 1990 in Sunseeker 1.  He was the first to fly on the sun’s rays over the Matterhorn in 2009 in Sunseeker 2. He and his wife Irena built the Sunseeker Duo and routinely fly it around northern Italy and over the Alps into Switzerland.  Eric has more hours piloting a solar-powered airplane than anyone, and Irena is probably the most experienced female solar pilot.  Only Bertrand Piccard and Andre’ Borschberg in the Solar Impulse would have anywhere need as much time at the controls.   Janice Brown, “a…former elementary school teacher” flew Paul MacCready’s Gossamer Penguin and Solar Challenger, even achieving a record altitude of 15,300 feet in 1981.  But Irena has by now easily exceeded Ms. Brown’s total solar flight time.

Over-the-nose shot from large opening in Duo’s canopy. Eric undoubtedly uses image processing software to eliminate long selfie stick from final image

Eric and Irena are professional photographers, and all of Eric’s designs have sliding canopies or large openings to allow use of the many still cameras and GoPros they carry on-board.

Landscape and skyscape frame a gorgeous aircraft

Recently, they’ve allowed Eric Conrad Lentz Gauthier to fly the Duo, perhaps because he’s a demonstrably capable flier.  His web page explains his extraordinary skills. “Eric is an American competition aerobatic pilot in Powered and Glider categories. He is the U.S. National Glider Aerobatic Champion and pilot on the United States Glider Aerobatic Team, which represents the U.S.A. in FAI sanctioned international competitions including the World Glider Aerobatic Championships held every year. Eric was also selected to represent the United States flying at the World Air Games Dubai 2015 and at the IOC World Games in Wroclaw, Poland 2017.

A Unique Airplane

Considering its large size (22-meter (72.17-feet) span, the Duo weighs only 290 kilograms (638 pounds) and carries two in an expansive cabin.  They even filmed a Skype commercial in it, with a large camera setup taking the place of a passenger. At a maximum weight of 470 kilograms (1,034 pounds), it settles onto the runway at 28 mph – ultralight speed.  Able to fly with the birds and leap the Matterhorn in a single bound, Duo is a super aircraft.

Unique Photos and Videos

In a short email, Eric expressed his wonder at the abilities of GoPro POV (point of view) cameras.  “When I started flying with cameras on my wing 40 years ago, I never imagined that a POV camera could take pictures like these!

“These are all cropped frame grabs from video footage taken with my GoPro Fusion.  Just the last few days of flying.”

All elements in harmony. Where else can one have such glorious experiences on only 22 kilowatts?

The Fusion is a 5K camera, a notch up from 4K video and able to “stitch” adjoining sequential frames into a full 360-degree panorama.  Its rather astounding “fish-eye” capabilities are unique and exreme.  Needless to say, great pilots flying over a gorgeous landscape and under an equally gorgeous skyscape are bound to bring back gorgeous images.


Beta Technologies Testing Actual Prototype

Kyle Clark heads Beta Technologies, an aircraft company flying under the radar until recently.  Beta’s prototype, based on an RDD LX7, uses eight electric motors driving one fixed-pitch propeller each.  These are mounted on rotating tubular arms that allow vertical takeoffs and landings with the propellers in horizontal orientation and a claimed 170 mph cruise when in vertical orientation.

VT Digger, an independent non-profit journal, reports, “Using homemade flight simulators, an array of 3D printers, a machine shop, and a team of nearly 40 staff and contracted engineers, Clark has big plans for his self-funded company, which occupies a hangar and other buildings at the Burlington airport. He intends to stand out for creating an aircraft with a power system that enables it to achieve the longest flight range amongst its peers.”

“’We’re going to develop the world’s longest-range, best-performing aircraft,’ he said.”

Wired, in a snarky mode, describes the Beta Ava as looking, “like what Tony Stark would build if he had an Edward Scissorhands phase.”  Despite the spindly nature of the landing gear and the multiple flailing blades, Ava is capable of flight on a blizzardy day with lake-effects snow blowing in its wake.

Beta’s prototype aircraft flying in Plattsburgh. The company is now developing a commercial aircraft at its hangar at the Burlington International Airport. The new craft, scheduled to fly in a year, has a different configuration but uses core technologies developed in the prototype, said company founder Kyle Clark. Photo courtesy of Beta Technologies

Common Sponsorship with an Electric R44

Sponsored in part by Lung Biotechnology, Beta’s program will lead to delivery of human lungs from hospital to hospital on inter-city routes.  The same program with OC Helicopters and Tier One Engineering resulted in a demonstration that covered 30 miles at 80 mph and an altitude of 800 feet.  The team won a Guinness World Record for the feat.

Martine Rothblatt (left) with Tier 1 electrified Robertson R44 and development team

Martine Rothblatt, head of the biotech firm, flew the mission with Ric Webb, founder of OC Helicopters in Orange County California.  That was on a nice, sunny day typical of SoCal.

Ava’s ability to maintain a stable run down a snowy runway presages longer flights in adverse weather – a significant capability for medical deliveries.   Ava’s 4,000 pound gross weight will allow medical personnel to accompany their precious cargo. Martine Rothblatt’s endorsement of these machines gives a certain gravitas to both endeavors.

Ava’s eight 143 kilowatt motors are arranged in four pairs, with an upper and lower motor and rotor combination.  Propellers counter-rotate, presumably to eliminate torque effects at each corner of the aircraft.  Top and bottom motors are separated by a controller pair in a well-ventilated housing.  Two battery packs totaling 124 kilowatt-hours power the upper and lower motors.  Failure of any component in either layer will be compensated for to enable continued stable flight.

Road Trip

Beta’s Ava has over 170 flights so far, and the company plans a trip from Kitty Hawk, North Carolina to Santa Monica, California sometime this spring or summer according to Wired.  Flying over Plattsburgh’s two-mile long runway, Ava has managed 100-foot altitudes and a top speed so far of 72 mph.  The airplane have achieved 18 minutes in a hover and an hour while tethered.

Clark, the only test pilot so far, will fly the cross-continent tour, 60 to 100 miles per leg, with one-hour recharging intervals.  A generator and solar-panel-laden bus will offer an expanding landing zone on its roof

On the Ava’s planned cross-country flight, the Beta team will follow along in their mobile charging vehicle, a converted tour bus outfitted with generators, solar panels, and an expanding landing pad on the roof.  Photo: Eric Adams

With a growing number of flight hours and solid backing from the woman who gave us Sirius XM satellite radio, Ava is off to a good start.  The next version will be bigger, more powerful,  faster and have greater range.  It will compete with Bell, Joby, and several of the over 130 eVTOLs under development.  Exciting times lie ahead.


Sailplane-Like Boeing Cruises on SUGAR

Boeing has sustained a decade-long program to develop aircraft that reduce the use of fossil fuels or eliminate it altogether.  SUGAR (Subsonic Ultra Green Aircraft Research) program designers have resorted to configurations that were a part of early high-performance sailplanes, those craft that soar on the energy of the very air around them.

Sailplane designers know that longer wings give a lower span loading: the weight of the airplane and its payload is spread over a greater span.  On powered craft, low span loadings give greater rate of climb for the same power and enable throttling back to get the same cruise speeds.  Longer spans usually lead to heavier structures, though.  Spars end up weighing more and wings are subject to twisting in the wind.

To get around these problems, early designers used highly-tapered wings to move the bending moment on the wings inward, and strut bracing to reduce the cantilevered segment of the wing.  Hawley Bowlus used these methods to make a 61-foot, nine-inch wingspan Senior Albatross sailplane weigh a mere 153 kilograms (340 pounds.  It could carry a 180 pound pilot for a gross weight of 520 pounds.  The wing area of 204.75 square feet gave an aspect ratio of 18.72 (area divided by span).  Considering its mostly wood and ply construction, it was strong enough for cross-country soaring.

Built of extremely light wooden construction, the Bowlus Senior Albatross is similar in configuration to the new Boeing design.  This example is in the Smithsonian Air and Space Museum  

The TTBW configuration has a high-aspect-ratio wing to minimize induced drag in the cruise. The long, thin wing is braced by trusses—similar to the Hurel-Dubois designs — that minimize the weight penalty of the longer span.

The Hurel-Dubois HD.10 of 1948 flew initially on only 40 horsepower but managed 133 mph and had a range of 621 miles because of the long, skinny wings (32.5:1 aspect ratio.

Boeing’s Transonic Truss-Braced Wing (TTBW) concept results in a 170-foot span, low-drag wing designed to fly at Mach 0.8, similar to current jetliners, but on less power.  This is crucial for hybrid electric power systems and for low fuel burn.  Originally developed in 2010 under the Boeing and NASA Subsonic Ultra Green Aircraft Research (SUGAR) program to study new configurations for ultra-efficient airliners, the concept has evolved to higher aspect ratio wings and higher speeds.

Shown at the January 8 American Institute of Aeronautics and Astronautics SciTech conference in San Diego. the revised TTBW is claimed to have an eight-percent fuel-burn advantage over a conventional configuration with cantilevered wing.

Graham Warwick, writing in Aviation Week, notes, “The latest version of the company’s Transonic Truss-Braced Wing (TTBW) can fly higher and faster than previous iterations thanks to its optimized support truss and adjusted wing-sweep angle.

Boeing’s program manager for transonic truss-based wings, Neal Harrison, says, the “new design is updated to be more consistent with current air travel,” and can be applied to aircraft of any size.  Tweaking the truss and wing sweep enables fuels savings of eight to ten percent compared to conventional cantilevered wings.  Harrison explains that a lightweight `170-foot span folding wing sits atop the airplane’s fuselage, supported by a truss composed of two major struts and two smaller “jury struts.”

Harrison adds, “We are essentially taking the wing aspect ratio and doubling it.  The aspect ratio allows us to reduce the induced drag – the drag due to the creation of lift. We get better performance out of the vehicle.”  Current narrow-body airliners have aspect ratios of about 8 to 10.  A Boeing 737 has a span of 118 feet.  Narrowing the wing chord and increasing the span gives the new truss-braced wing an aspect ratio of about 16-18.  Outer wing panels will fold upward to enable the TTBW to use the same airport gates as a 737.

“Flutter is a primary design consideration for higher-aspect ratio designs.”

“Artist’s concepts of the refined TTBW design released by Boeing show the increased sweep of the high-set wing and the revised design of the truss. The main member has increased chord at the fuselage, forward sweep and tapers toward the junction with the wing.” (Aviation Week)

Even though the aircraft pictured appears to be conventionally powered, Aviation Week reports, “…NASA is studying versions of the TTBW concept with hybrid-electric propulsion. These have electric motors integrated into the turbine engines. An electric-powered ducted thruster on the tail ingests the fuselage boundary layer and re-energizes the wake, reducing drag and energy consumption.”

NASA’s and Boeing’s studies on this configuration can be found here for the basic wing configuration, here for electrifying the concept, and here for an analysis of the aeroelasticity of the wing.

Flying with less drag, eventually with quieter electric motors and improved economy, the TTBW configuration will certainly add a graceful appearance to future flight.


Bell Nexus Debuts at CES 2019

This year’s Consumer Electronics Show (CES) had over 4,500 exhibitors, and one major aircraft company showing off its Bell Nexus sky taxi and its Autonomous Pod Transport (APT)Fast Company reported that three major trends emerged: the thousands of devices that link to “virtual assistants” such as Alexa (28,000 apps), the introduction of a slew of Apple products, and the changes in transportation new technology will bring.

Bell Nexus drew crowds at CES 2019

Fast Company noted, “This long-term–and wildly futuristic–strategizing was on full display at CES. For starters, the Uber partner Bell showed off a second-stage concept of its flying car that both companies swear they will begin testing in 2020. (This has been on the docket for a while.) A full-scale model on the CES floor promised to fly five people at speeds reaching 150 mph.  Of course, it didn’t actually fly, but it’s being taken seriously for an important reason: Bell is an established aircraft developer that makes the propulsion technology behind the V-22 Osprey (the crazy-expensive military helicopter plane thing).”

Bell Nexus – A Team Effort

The Nexus team effort, comprising Bell Helicopter, Safran, EPS, Thales, Moog and Garmin, focuses on crafting Bell’s VTOL aircraft and promoting on-demand mobility.  The Nexus is a five-passenger (or four-passenger, one pilot) electric vertical takeoff and landing (eVTOL) vehicle designed to fulfill the vision of on-demand mobility.  Powered by a hybrid system developed by French manufacturer Safran, the six tilting ducted fans will enable roof-top operations and speedy transit.

Safran, a major supplier of aviation engines, with over 72,000 produced since the company’s founding, has developed a hybrid system multi-rotor VTOL system capable of producing more than 600 kilowatts total energy and 100 kilowatts of electric energy for recharging the onboard batteries.

Jean-Baptiste Jarin, Safran Helicopter Engines Vice President, Hybrid Propulsion System Program explained the significance of the Bell-Safran partnership.  “This partnership with Bell in the on-demand mobility sector is a strategic opportunity for Safran.  Nexus is the first of a new breed of aircraft, it opens the doors to new markets and new missions. Fully committed to these challenges and sharing a common vision with Bell, we now look forward to seeing it fly”.

Scott Drennan, Vice President of Innovation, added, “Bell is excited to unveil the Bell Nexus at CES and to share this exciting time with our partners. The Bell Nexus delivers a nexus of transport and technology, comfort and convenience. “We look forward to continuing the development of technology with Safran to bring this nexus to life.”

According to Safran, the “Hybrid-electric propulsion solutions (HEPS) being explored by [their] teams are the most efficient way to enable multi-rotor VTOL aircraft to meet future safety, emission and affordability standards.”  By 2025, Safran is committed to becoming the market leader in HEPS technology.

EPS will provide the energy storage systems, Thales will provide the Flight Control Computer (FCC) hardware and software, Moog will develop the flight control actuation systems and Garmin will integrate the avionics and the vehicle management computer (VMC).

Autonomous Pod Transport (APT)

APT is a family of transport vehicles, varying in size and payload to “serve many mission sets from medical, law enforcement, offshore missions and on-demand delivery services.”   CES attendees were told, “Bell is expanding into a new industry to show the full spectrum of our capabilities and the real-world challenges APT will address.”

Bell treated visitors to a demonstration of Future Flight Controls in simulators that collected data to “determine what actions and interfaces are intuitive to the average potential operator and what prior experiences and abilities contribute to these opinions.”

The partnership will help explore the aerodynamics, power, and control of this new vehicle, but most important, the public’s willingness to accept this new leap in transportation.