APUS Introduces Two Zero Emission Craft

We’ve written several times about structural batteries in this blog, from Dr. Emil Greenhalgh’s early research at Imperial College to more recent efforts along the same line.  Interestingly, the basic idea remains very much the same over a decade.  Energy storage would take place in a monocoque-type structure that could use carbon fiber, fiberglass, and even graphene as  a structural material, while acting as a battery.  Now some of this thinking is being applied to hydrogen storage in wings.


APUS, an aircraft design, structure and certification operation in Strausberg, Germany, offering a full range of services including flight training.  They recently announced two new craft, both featuring hydrogen fuel systems contained in a novel “…  patented structurally integrated hydrogen storage system, known as TubeStruct™.”  In the shadow drawings of the airplanes, the tubes appear as though they could double as redundant wing spars.

APUS i-2  will be comparable in dimensions and performance with more conventional light twins, but will be a zero-emission vehicle

The i-2, a four-seat Normal-Category (CS-23) aircraft; and “The APUS i-6 is a technology demonstration platform with 2.8t MTOM (Mean Take-Off Mass).”  Both will be propelled by Siemens SP-70 motors (or whatever the Rolls-Royce equivalent will be)* – two on the -2 and “up to seven” on the I-6.

The i-2 will contain a hydrogen fuel cell in its streamlined nose powering two electric motors on its wings.  The fuel cell will draw H2 from TubeStruct in its wings, which, according to APUS,  “permits up to 25-percent higher specific energy density vs. standard hydrogen fuel tanks and 10X better energy density than fully-electric aircraft, all while avoiding the use of rare minerals that batteries do.”

Dimensions and performance are similar to other light twins, with an empty weight of 1,300 kilograms (2,860 pounds) and a payload of 500 kilos (1,100 pounds).   It can carry its pilot and three passengers 800 kilometers (496 miles) at a true airspeed of 150 knots (172.5 mph).

The i-6 is listed as a, “Technology demonstration platform optimized for distributed propulsion,”  and is, “Also designed for turbo-prop configuration.”  In its hydrogen configuration, it will include the TubeStruct containment vessels.  Meant to allow varied systems the i-6 can be powered by a 500-700-kilowatt (670 – 938 hp.) Diesel generator set for electrical power to the distributed motors.  Alternatively, a Rolls-Royce M250-B17 turbine can produce 450 kilowatts (603 hp.) to turn a single propeller in the nose.  In its depicted version, a 230-400 kW fuel cell could provide power for the seven electric motors that would provide added lift across the entire wing and horizontal tail.

APUS i-6 will be more radical in its configuration, with distributed electric propulsion, variety of power sources

Designers have thought out the many possibilities with care.  APUS explains, “The large CG range granted by the canard permits an extremely high level of modularity and interchangeability for propulsion system components. The high-voltage and high-current electrical systems will be researched with a scientific approach. Furthermore, certification aspects, such as reliability, lightning protection and electro-magnetic compatibility, are to be investigated.”

*Rolls-Royce having recently purchased Siemens’ electric aircraft motor enterprise.

Green Speed Cup

Robert Adam, head of APUS’ Flight Services Department, leads an event called the Green Speed Cup, a kind of aeronautical economy run that allows competition between diverse aircraft.  This year’s event will be held from June 5 through June 7, 2020.  Details will be announced here soon.  Perhaps the i-2 or i-6 will be on hand.

Green Speed Cup 2017

A nice wrap up of the Green Speed Cup 2017. Thanks Dronesperhour for creating this video.

Posted by Green Speed Cup on Friday, July 28, 2017

This short video of the 2017 competition shows the mixed bag of participants – everything from vintage to advanced technology.


Wright Electric Reveals Big Plans

While most anticipated new electric aircraft don’t seem to exceed 50 seats, Wright Electric has begun a more ambitious program for its 186-seat electric airliner, Wright 1.  In a January 30 press meeting at the Refinery Hotel in lower Manhattan, Wright announced plans to move forward with their design and testing program for a substantial electric airliner.

Wright CEO Jeffrey Engler added: “Wright Electric is dedicated to bringing low-emissions 186-seat electric planes systems to market. Wright Electric’s mission is to make commercial aviation greener, and our megawatt engine program is the next step in making our mission a reality.”

Wright’s plans include moving its headquarters to Albany, New York, “to take advantage of the extraordinary local engineering talent.”  Wright will work with BAE Systems, “…to help to accelerate the new technology.”  A big part of that new technology will be the 1.5 megawatt electric motor and supporting three kilovolt inverter to control all those currents.  Such powerplants are substantially greater than anything else currently (almost impossible to avoid puns) flying.

Two of the most aggressive, for instance, Harbour Air in Vancouver, B. C. and Eviation in Qadima, Israel use different versions of the Magnix Motor – originated in Australia and now headquartered in Vancouver.  The three smaller Magni 250 motors on the Eviation Alice will produce a total of 900 peak kilowatts (1,206 horsepower), and the single larger Magni 500 on the Harbour Air DHC-2 Beaver puts out 560 kW, or 750 shaft horsepower.  The Alice will haul two pilots and nine passengers, the electric Beaver a pilot and six passengers.

Closer to the projected Wright 1, a Boeing 737-800 is a single-aisle, 189-passenger airliner.  It has two engines that produce 24,200 to 27,400 pounds of thrust each.  To keep things simple, consider a conversion that says one pound of thrust equals one horsepower at 375 mph.  The Wright 1’s motors will have to produce a rough equivalent of the Boeing’s thrust to generate that cruise speed.

As seen in the video, clusters of smaller motors will be buried in the wings.  It will be interesting to see how this configuration, similar to early jetliners such as the DeHavilland Comet will work out in electric form.


Salient features of the Wright 1 – a challenging leap into an electric airline future

Wright’s ambitions include conducting ground tests of its motor in 2021 and flight tests in 2023, with entry into service by 2030.  These are ambitious, indeed, with 1.5 megawatts equaling about 1,500 Teslas.  Each 100 kW Tesla S battery pack weighs about 1,056 pounds (battery modules), so 1,500 would weigh 1,584,000 pounds, about nine 737-800’s.

This may seem like a ludicrous expectation, to borrow a Tesla performance title, but consider that batteries will improve over the next decade, and that performance considerations will be different from the 588 mph cruising speed of the Boeing.  Let’s look at a more reasonable 300-350 mph cruise – fast enough for the short routes planned for the Wright 1. Total aircraft drag decreases by the square root of the speed, and power required by the cube root.  That’s part of why Green Flight Challenge aircraft could achieve such distances and low weights even with the batteries available 11 years ago.

With Tesla batteries available today, the battery weight drops to approximately 1/9th of the 588 mph size pack, or 176,000 pounds.  With 2X battery of the future, that becomes 88,000 pounds.  Note that these are spitball figures by a mathematically-challenged English major, but they may be achievable and are 2X the 44,685 pounds of fuel carried by a 737-800.

With light-weight electric motors, as in the smaller examples now flying, battery weight can be offset by reduced powerplant mass.  Perhaps it’s not as difficult as it first seems.  Comments and corrections are more than welcome.

The easyJet Connection

Wright’s partnership with easyJet, a European budget airline, is a mutually advantageous one.  The airline prizes efficiency and has reduced its carbon emissions per passenger-kilometer by 33.67 percent since 2000, and targets a 38-percent reduction by 2022.  It’s also the first major airline to offset the carbon emissions from all its flights.  Wright’s press release emphasizes, “Their priority is to continue reducing their carbon footprint in the short-term while they support the development of innovative technology to accomplish their long-term goal of carbon-free aviation, which Wright is making possible.”  The video makes it plain that flying easyJet is not a great deal different from flying coach in America.

Meanwhile, Wright is working with agencies such as NASA and the Air Force Research Laboratory to improve Wright 1’s fuselage aerodynamics.

Johan Lundgren, CEO of easyJet, commented: “This is another crucial step for our partner Wright Electric to move towards the introduction of commercial electric aircraft and it is exciting to see their ambitious timeline for testing and entry into service.

“Battery technology is advancing at pace with numerous US government agencies now funding research into electric aviation– all of these developments help us to more clearly see a future of more sustainable operations.

“We know it is important to our customers that we operate as sustainably as possible – our carbon offsetting program has been positively received by our customers and we have now offset more than nine million passenger journeys – but we are clear this is an interim solution until new technologies become available and we can see more clearly than ever a future that is not exclusively reliable on jet fuel.”

Matt Rogers, founder of Incite.org, a venture capital firm, commented: “This is a milestone for Wright Electric and for the future of aviation.  Addressing the climate crisis requires innovation and partnership, especially in the hardest areas to decarbonize.  Wright Electric’s progress demonstrates how both new and established aviation leaders can come together to pave the way for low-emissions travel and set an example for others.”

Ehtisham Siddiqui, Vice President and General Manager of Controls and Avionics Solutions at BAE Systems, commented: “We are discussing collaboration opportunities with Wright Electric on the development of flight controls and energy management systems for its electric aircraft.  Our new development builds on decades of experience in both domains, as we strive to help shape the future of flight.”

With so much riding on this announcement, and so many questions still to answer, this news will be unfolding in months to come.  The partners seem well suited to driving this green new wave.


Eviation’s Alice Involved in Fire

Time magazine lauded Eviation’s Alice last year, ranking it as one of the 100 Best Inventions of 2019.  Alex Fitzpatrick compared its green goodness to the GHG-loaded nature of commercial aviation.  “Flying is dirty work—the aviation industry emits nearly a quarter of total transportation-­related greenhouse-­gas emissions in the U.S., according to the EPA. One way to clean it up could be ­Eviation’s all-electric Alice, an Israeli-made nine-seater meant to convince the gas-­guzzling aviation world that electric power is ready for takeoff. “The real innovation is in the lightweight materials rather than the batteries and motors and controllers and all that,” says Eviation CEO Omer Bar-Yohay. If successful, the design could pave the way for larger electric commercial aircraft. Alice, which has a range of 650 miles and should be quieter than gas-­powered aircraft, begins flight testing in 2020.”

Eviation’s Alice in sunnier times at the Paris Air Show last summer

The bright future for the tri-motored airplane, which shone at the Paris Air Show and a prototype of which was about to undergo ground and flight testing at Prescott, Arizona, was darkened by a late-night fire.  The fire caused extensive damage to the craft.  AIN Online reports, “A fire broke out during ground testing of Eviation’s all-electric Alice aircraft on January 22 at Prescott Regional Airport in Arizona. The company said that the fire is believed to have been caused by a fault with a ground-based battery system. It has yet to confirm how extensively the prototype aircraft might have been damaged in the incident.


The Prescott Fire Department was on standby for the planned test and quickly extinguished the fire, which caused no injuries. Eviation has begun an investigation into the full cause of the fire and has not said how the incident might affect plans to begin flight testing the aircraft.”

An interview airport manager Robin Sobotta on the following morning does not give a great deal of added detail.

Two over Alices were being brought to the states for evaluation and eventual test flying at Moses Lake, Washington.  Eviation has had at least 20 suppliers working on various sub-assemblies for the aircraft.  Batteries, stated to be by Kokam in 2019, constitute a large portion of Alice’s total mass, and even CEO Omer Bar-Yohay told reporters at the Paris Air Show that, “It’s basically a huge battery with some plane painted on it.

Karl Kaser, Dipl. – Ing. and CEO of Kasaero GmbH in Stuttgart, is one of Eviation’s suppliers.  In an email to your editor, he explained his company’s role in the design of the plane’s wings.  “We have been designing the structure of the wing and support the production in a consortium with Singapore companies and the German Fraunhofer Institute.”

His company web site tells of the international cooperation that made the completion of Alice’s wings in exceptionally speedy order.  “Eviation has made it: The design and construction of the innovative new electric aircraft design “Alice” were completed in record time for the Salon Internationale de l’Aéronautique et de l’Espace.

“The dedicated development team of the Composite Cluster Singapore and Kasaero, in cooperation with the Fraunhofer IGCV in Augsburg, structurally dimensioned and designed the high-performance wing of the Alice in just 8 months.”

You can read the comprehensive overview of the partners’ work on Alice in this issue of Business Focus magazine.

We wish for a full and thorough investigation into the cause and an equally swift resolution.  We hope for the best for all involved.


UAM Realization May be Closer than We Think

We are on the verge of big happenings in the Urban Air Mobility (UAM) world.  Large amounts of money are flowing into the coffers of those companies which dared to pioneer in the area.  Large firms are partnering with these aerial startups.  And the Federal Aeronautics Administration is paying attention while actively pursuing certification for the new machines headed our way.

Jay Merkle, FAA Certification and Airspace Integration

At the Transportation Review Board’s annual meeting in Orlando, Florida, Jay Merkle, head of the FAA’s UAS integration office, told attendees that six (Urban Air Mobility) UAM  vehicles are “well along,” according to a report in Aviation Today.   He held that the growing market is ““more than just hype … this is more than just promotional videos.”  Merkle apparently feels current regulations such as FAR Part 23 are adequate to help these new electric Vertical Take Off and Landing (eVTOL) machines be certified.  Merkle feels the machines in progress can provide service “for regional air trips… from 30 miles to 300 miles.”

Even more promising, Merkle added, “We are beginning to work on integrating them operationally, so the pilot requirements, the airline operating requirements, and then we’re also beginning to work on the airspace integration as well.”  Learning from mistakes in attempts to meld smaller drones into the overall air traffic control program, the FAA is forging ahead with its programs for larger craft.

He even spread the word at the Farnborough International Air Show in an interview with Alan Peaford, editor-in-chief of FINN (Farnborough International News Network).

The Probable Six

Although Merkle did not directly name the six UAMs “well along,” others speculate they include:

EHang, 216: eHang has over 1,000 flights to its credit, even flying its own executives and board of directors, and making public flights in Asia, Europe and the Middle East. Launching an unmanned flight over Kitty Hawk, North Carolina early this month, eHang has already achieved temporary certification allowing pilotless flights in the United States. The company recently delivered at least two batches of 216’s (two passengers, 16 rotors).  Judging from the video, each “batch” might involve 19 eHangs.

EHang’s Founder, Chairman and CEO Hu Huazhi said: “This delivery of AAVs marks a major step forward in EHang’s efforts to offer a full-stack solution for the emerging urban air mobility market on a global scale. We will continue to work closely with our customers, business partners and regulators on various issues including infrastructure rollout, flight permit, trial operations and technical support to enable a new era of urban air mobility.”

Elroy Air, Chaparral: Elroy, which is developing a hybrid-electric, autonomous VTOL aircraft for 300-pound cargo transport up to 300 miles, recently announced a partnership with EmbraerX to “cooperate on technical, certification and business opportunities,” according to CEO David Merrill. The Chaparral first flew in August 2019.

Similar in configuration and mission to the Sabrewing, the Chaparral  is smaller, lighter, and carries a smaller payload.

With EmbraerX collaboration, Elroy Air explores cargo drone operational models for up to medium range cargo deliveries.  Air Cargo World reports, “Embraer’s innovation-focused subsidiary EmbraerX and cargo drone developer Elroy Air announced a collaboration agreement Wednesday. The partnership gives EmbraerX access to the commercial air cargo market and gives Elroy Air access to Embraer’s expertise in technical development of aviation equipment.


Joby Aviation, S-4: Joby has been on radio silence for a few years – though it demonstrated a 15-mile flight in 15 minutes for Bloomberg Businessweek as far back as February 2018. More recently, Joby joined Uber Elevate as the ecosystem’s only vehicle partner publicly committed to being commercial-ready in 2023.  The S-4 has an unstated number of hours in its log book, but the fact that two years ago Joby was willing to demonstrate its already impressive capabilities to reporters indicates it’s probably done more since.


Kitty Hawk / Wisk, Cora: Backed by Google co-founder Larry Page, Kitty Hawk’s second design — a two-seater intended for autonomous air taxi use — has flown extensively in New Zealand and the U.S., with almost 1,000 test flights reported in June 2019 (and over 1,200 noted on the video). That same month, Boeing announced a strategic partnership specifically with Kitty Hawk’s Cora division, creating a new company called Wisk.aero. Wisk says it is “working closely with the New Zealand Civil Aviation Authority (CAA),” but also mentions aspirations to “expand in other markets.”


Sabrewing, Rhaegal RG-1: This California-based startup is building hybrid-electric autonomous VTOL drones to transport heavy cargo, with a payload capacity up to 1,000 pounds. In March 2019, Sabrewing announced a $43 million purchase agreement with the Aleut Community of St. Paul Island in Alaska. CEO Ed De Reyes told Avionics at the time his company was close to finishing production of its first aircraft and plans to start flight testing at the end of the year.Sabrewing is targeting 2023 for certification through Part 23. The company is working with Garmin, FLIR, uAvionix and others for the Rhaegal’s avionics suite.

Sabrewing plans on developing both two versions of its aircraft: one that with a payload capacity of 800 pounds and a later model with a capacity of 4,400 pounds. The company plans to power the aircraft with a hybrid system that uses a gas turbine to generate electricity for the electric motors. This design is similar to the one currently being tested by Rolls-Royce.

St. Paul Island, an isolated Aleut community near the Arctic Circle

According to Sabrewing, the ACSPI (Aleut Community of Saint Paul Island — about a third of the way between Alaska and Russia ) has already begun various types of drone operations. In exchange for testing facilities placed on the island, Sabrewing will provide equipment and training for the ACSPI community, who can then initiate and operate a complete test range complex.

Volocopter, VoloCity: The German air taxi developer’s electric multicopter designs made headlines throughout 2019, with the ‘2X’ — a precursor to VoloCity, unveiled in August 2019 as the company’s first commercial design — flying high above Singapore and Stuttgart, Germany.While Volocopter hasn’t given any public indications it is pursuing certification in the U.S., the company received the first-ever design organization approval (DOA) from EASA that includes electric VTOL aircraft.


One wild card: Aviation Today suggested that Detroit-based Airspace Experience Technologies (or AirspaceX), which is developing its Mobi-One air taxi or cargo delivery concept, may be a “wild card” possibility.  Airspace X targets 2019 for tooling and certification and 2021 for aircraft production. A sub-scale model displayed at Uber Elevate 2018 had already flown in limited tests, according to co-founder Jon RimanelliDr. Sangita Gupta, another co-founder, spoke at SAS 2019 about the company’s aspirations and abilities.

A Necessary Caution

In part of his address, Merkle pleaded, “Please don’t ask to predict things,” he said. “We’re just horrible at it.”



Hydrogen Instead of Batteries?

As battery makers worldwide strive to develop safe, high-energy-density cells, Breezer Aircraft, a German small-aircraft manufacturer, unveils plans to power one of its ultralights with a hydrogen fuel cell.

Breezer’s  B400-6, receiving 600kilogram certification by the DAeC (German Aero Club), is light enough to enable a small fuel-cell-motor combination to power it.  Usually powered by the ubiquitous Rotax range of engine, an electric version will initially to be driven by batteries, and then powered by a hydrogen-fuel cell.

Presentation of the project idea at Lüneburg airfield. The metal construction allows both enough space and a compact installation of an electric drive train, the energy of which is to be obtained from fuel cells. Owner Dirk Ketelsen also operates his own wind farm. which will also produce hydrogen from electricity in the future . There is hardly a better way to use wind energy.  Photo and caption from http://www.electric-flight.eu/

eCap and Re-Fire

eCap, a German company specializing in systems integration and installation for a diverse range of classic and modern vehicles, will work with Breezer on the first installations.  eCap’s demonstrated ability to convert everything from an antique farm tractor and classic cars (including a DeLorean) to modern buses and delivery trucks shows their range.

2015 sampling of vehicles converted by eCap

Employing state-of-the-art technology and techniques such as reverse engineering leads to 3D CAD models from which ECap develops prototypes.  Perhaps most important, “eCap works completely independently of exclusive suppliers in the development of subsystems and complete systems. This means that we select and combine the ideal components from a large selection of suppliers and products for all aspects of electromobility in accordance with performance requirements and budgets.”  They work with prototypes, pilot production and small series operations.

Re-Fire is a Chinese creator of fuel cell power plants, producing fuel cells and drives for cars, trucks, and buses.  Their 46-kilowatt powerplant will probably be closest to that needed to fly an ultralight airplane.

Re-Fire 46kW (62 hp) unit. You still need a motor to drive that big fan in the nose

It weighs 160 kilograms (353 pounds), can fire up at temperatures above -15° Centigrade (5° Farenheit), and run at up to 56-percent efficiency for up to 12,000 hours.  It can endure IP67 standards punishment, with complete protection from dust intrusion and the ability to be immersed in water to a depth of one meter (3.28 feet) for up to 30 minutes.  All this comes in a 926 millimeter (36.45 inch) x 550 mm (21.65 inch) x 408 mm (16.06 inch) package.


 Dirk Lehmann, founder of eCap, sees a potential market for his company’s expertise. “For the coming years , we expect a growing need for reliable, safe and environmentally friendly propulsion and conversion solutions for aircraft.”  Although the drive trains will also be offered to other manufacturers, Dirk Ketelsen, managing director of Breezer Aircraft thinks the systems are still too expensive for wide-spread adoption.


Pigeon Feathers!

We lag behind nature in many areas, and constantly need to remind ourselves of our relative ignorance of her many secrets.  Feathers are a case in point, and Stanford University researchers found that, unable to duplicate the nature of these lightest of airborne structures, they needed to use the real thing in their latest drone.

The IEEE Spectrum reports, “The few attempts at making artificial feathers that we’ve seen in the past have been sufficient for a few specific purposes but haven’t really come close to emulating the capabilities that real feathers bestow on the wings of birds. So a century later, we’re still doing the rigid wings with discrete flappy bits, while birds (one has to assume) continue to judge us for our poor choices.”

A Feathery Primer

Before looking at Stanford University’s Pigeonbot, we will indulge a few minutes learning how complex a seemingly simple feather really is.

Those wishing to delve deeper can turn to a marvelous book by Thor Hanson, Feathers, The Evolution of a Natural Miracle.  Hanson recounts the evolution and biology of feathers and tosses in compelling anecdotes.  One such explains that the most expensive things lost in the sinking of the Titanic (aside from the 1,200 lives) were $400,000 (millions now) in mainly ostrich feathers bound for New York milliners – part of the feather craze in fashion then.

The Trouble with Feathers

As seen in the near-microscopic analysis of feathers in the first video, feathers are extraordinarily complex, with properties that seem to vary between velco grabbiness and banana-like slipperiness.

Unable to duplicate those characteristics and complexity, researchers at Stanford University had to find another way to plume their robotic pigeon.  David Lentink, assistant professor of mechanical engineering and head of Stanford’s Bio-Inspired Research & Design (BIRD) Lab, explains the difficulties. “Feathers aren’t just more complicated to manufacture, but you have to find some way of replicating and managing all of the complex feather-on-feather interactions that govern wing morphing in real birds. For example, by examining real feathers, the researchers discovered that adjacent feathers stick to each other to resist sliding in one direction only using micron-scale features that researchers describe as ‘directional Velcro,’ something ‘new to science and technology.’ Real feathers can slide to allow the wing to morph, but past a certain point, the directional Velcro engages to keep gaps from developing in the wing surface. There are additional practical advantages, too: ‘they are softer, lighter, more robust, and easier to get back into shape after a crash by simply preening ruffled feathers between one’s fingers.’

Simplifying Control

While feathers themselves may be irreproducible, Lentink’s student researchers discovered that “birds maintain control by morphing the shape of their wings,” which turned to be relatively simple to imitate.  The student-made PigeonBot uses a pair of “biohybrid morphing wings” with mechanical undergirding and real feathers.

Morphing consists of movements about two joints on the bird’s wings corresponding to the wrist and finger joints on a human.  Lentink found that simply movements of the finger joints could induce rolling, “and that this technique is inherently much more stable than the aileron roll used by conventional aircraft.”

With the real feathers elastically connected to a pair of robotic bird wings with wrist and finger joints that can be actuated individually, PigeonBot relies on its biohybrid systems for maneuvering. Image: Lentink Lab/Stanford University

“The other cool thing we found is that the morphing wing asymmetry results automatically in a steady roll angle. In contrast aircraft aileron left-right asymmetry results in a roll rate, which the pilot or autopilot then has to stop to achieve a steady roll angle. Controlling a banked turn via roll angle is much simpler than via roll rate. We think it may enable birds to fly more stably in turbulence, because wing asymmetry corresponds to an equilibrium angle that the wings automatically converge to. If you are flying in turbulence and have to control the robot or airplane attitude via roll rate in response to many stochastic perturbations, roll angle has to be actively adjusted continuously without any helpful passive dynamics of the wing. Although this finding requires more research and testing, it shows how aerospace engineers can find inspiration to think outside of the box by studying how birds fly”.

Researchers are not patenting their discoveries, having “decided … to help proliferate our discovery to the benefit of society at large” in the hopes that anyone who makes a huge pile of money off of it will (among other things) invest in bird conservation in gratitude.”

In future, Lentink wants to add a biohybrid morphing tail, legs with grasping feet, and additional actuators.  Perhaps he can find a way to do away with the un-bird-like propeller, a giveaway that might not impress other avian creatures.

A Wind Tunnel for Birds

David Lentink in Stanford wind tunnel for birds and drones



Supercaps for Supercars – and Sky Taxis?

Your editor has asked for years if batteries in electrically-powered aircraft could be augmented by supercapacitors, devices able to unleash significant amounts of power quickly.  The usual answer is that the added weight of supercaps that could add power on demand would be about that of added batteries to equal the performance.

We wrote about the use of super capacitors in KERS (Kinetic Energy Recovery Systems) used in Formula racers and even at LeMans.  At around the same time, Mazda tucked supercaps under the front wheel well on some models to capture waste energy from braking.  That energy could then power electric systems in the car and even recharge the main battery.

 In an explanation and comparison of lithium batteries and supercaps, Matt Ferrell gives a reasonable overview of the two and how they will probably evolve in the future.  As he notes, Tesla recently purchased Maxwell technologies, possibly to fill what Maxwell describes as the “energy gap for fast-response, high power delivery solutions.”

 Lamborghini and MIT Double the Energy Density in Supercapacitors

 Design News reports that MIT and Lamborghini, having partnered on developing advanced supercapacitors for the last two years, recently announced a patented technique for doubling the energy density of capacitors.  The advance, “synthesized by professor Mircea Dincă’s team in the laboratories of MIT’s Chemistry Department with the support of Lamborghini’s Concept Development Department, is based on… the “Metal-Organic Frameworks” (MOF) concept.” Maurizio Reggiani directs the Lamborghini department.

Metal–organic frameworks  (MOFs), a new class of  crystalline porous materials, have gained extensive explorations as a highly versatile platform for functional applications in many research fields.

According to Design News, “The molecular structure of this family of materials makes it the ideal candidate for producing electrodes for high performance supercapacitors of the future, because it maximizes the amount of surface area exposed to electric charge in relation to the mass and volume of the sample.”

Reggiani (left) and Dincă (right). Image source: Automobili Lamborghini

Great in a Great Car – Will They Work in Econoboxes?

Because the super materials are not yet in a supercar, questions arise whether the MOFs can be made in commercial quantities at a price that dips below the $3.7 million, cost-is-no-object heights of the Lamborghini Sián’s components.  Its drivetrain features a naturally-aspirated, 785-horsepower V-12 engine, with a 34-horsepower, 48-Volt motor “incorporated into the gearbox to provide immediate response and improved performance.”  An extra 4.3-percent power may not seem like much of a kick in the pants, but does provide acceleration while reducing the load on the engine.  Not pushing the engine past its 8,500 rpm redline is a welcome longevity enhancement for a pricey investment. Supercaps are  immediately responsive, not requiring the spool-up time of a turbocharger.

Able to sell all the supercars it can build, Lamborghini is probably not concerned about the realities bean counters in more plebeian companies impose.  Reggiani says, “Costs have not been evaluated yet.”

GreenCarCongress.com notes the Sián energy storage is three times more powerful than a battery of the same weight and three times lighter than a battery producing the same power.  The article adds, “The electric system with the supercapacitor and e-motor weighs only 34 kg, thus it delivers a remarkable weight-to-power ratio of 1.0 kg/hp. Symmetric power flow ensures the same efficiency in both charging and discharging cycles—the most lightweight and efficient hybrid solution.”  Considering the system is self-contained and recharged every time the driver pumps the brake pedal, it seems a reasonable boast for the essentially mild hybrid setup.

Reggiani explains why Lamborghini pursues this line. “There’re several very interesting characteristics.  The power density, first of all, which makes the capacitors much more powerful compared with batteries — up to three times more power for a given mass — with a symmetrical behavior which makes them able to recuperate as much power as they can deliver.  Under this aspect, the difference with batteries is huge.”

Hidden by this cover is the Sián’s super capacitor. Image source: Automobili Lamborghini

Reggiani sees other benefits.  “Then, the very low electrical resistance, which means high efficiency and low heat dissipation, and the very long life, measurable in millions of cycles in comparison with the thousands of cycles of the batteries.”

Aerial Applications?

As supercapacitors and batteries increase in power and energy storage capabilities, one wonders if coming changes will change the preferences designers have for their applications.  Since academia and industry are progressing on both fronts, we anticipate great things to come – regardless.


eHang Flies for Real at Kitty Hawk

eHang has been busy over the past year, with demonstration flights worldwide, and last week in Kitty Hawk, North Carolina – the birthplace of aviation.

Not a Long Commute

In March, 2019, EHang founder, Mr. Hu Huazhi commuted via EHang AAV (Autonomous Aerial Vehicle) in Guangzhou, China.  As you can clearly see, it’s not a long commute, but a demonstration  of the faith the founder and others have in the machine.  As reported here two years ago, the company flew its entire executive group and and Guangshou city officials in their two-seat machines.  eHang reports on their extensive testing and demonstration flights: “To date, EHang has safely conducted over two thousand trial flights in the United States, China, Austria, the Netherlands, Qatar, and the UAE to ensure that its AAVs operate safely and reliably in different areas globally.”

eHang, already prosperous from model drone sales, has invested heavily in a corporate infrastructure and international marketing.  They note a Blue Paper from Morgan Stanley Research that projects an “addressable market” of $1.5 trillion for autonomous aircraft by 2040.  “With the core concepts of autopilot, full redundancy safety design and cluster management by intelligent command and control center, pilots are no longer necessary for a flight, while passengers only need to click the ‘take-off’ button to fly to the selected destination. EHang will provide every passenger a truly enjoyable journey by the safe and intelligent autopilot system. In February, 2018, EHang has unveiled footage of the latest test flights of EHang AAV in Guangzhou, China. Since then, EHang AAV conducted an array of flight demonstrations in Amsterdam, Doha, Vienna. EHang is a world’s leading autonomous aerial vehicle (AAV) technology platform company based in Guangzhou, China.”

eHang’s First Certified Flight at the Birthplace of Aviation

This represents the first time that the EHang 216 has received flight approval from the Federal Aviation Administration (FAA). While this was a non-passenger flight, EHang is working with the FAA to secure approval for a passenger trial flight of the EHang 216 in the near future.

“Our mission is to make safe, autonomous, and eco-friendly air mobility accessible to everyone and this trial flight represents a significant step towards bringing our urban air mobility solutions to the U.S. market,” said EHang founder, chairman, and CEO Huazhi Hu. “Pilotless air taxis have the power to transform everyday life in urban areas since they can lessen pollution, expedite emergency services, and save individuals and businesses time and money through shorter travel times.”

Roy Cooper, the North Carolina Governor, said, “We are proud to have the first autonomous aerial vehicle flying in North America, in North Carolina. Obviously, they are beginning this all of the world and this technology and what it means for transportation, both cargo and passengers, is pretty astronomical. This gonna be very positive for the economy. We want North Carolina to be on the cutting edge of this technology and we’re proud to have EHang here to show and demonstrate to us what can be done with this technology. It’s taking off. We North Carolina has become the pilot that can help move this kind of business forward. We are excited about that.”

To date, eHang has safely conducted over two thousand trial flights in the United States, China, Austria, the Netherlands, Qatar, and the UAE to ensure that its AAVs operate safely and reliably in different areas globally.

Real Sound

Your editor selected this video because it has actual rotor sounds instead of a music soundtrack.  There’s no telling how much the sound is modulated.

An eHang Overview

 EHang has already delivered 38 units to customers as of December 5, 2019, putting it ahead of the pack with demonstrably capable machines while others display larger concept vehicles.

eHang 216 fly formation over home city of Guangzhou, China

Before its debut flight in the U.S., two EHang 216 AAVs completed simultaneous trial flights of their commercial sightseeing applications in Guangzhou, China on November 30, 2019. Guangzho will be eHang’s first urban air mobility pilot city, with trial flights demonstrating the AAV’s ability to use a variety of landing platforms.

ADDED January 15, 2020

This came out just three hours ago, and is redundant in some places, but includes a stopped propeller demonstration that is fairly compelling.

Delivery Drones with DHL

Showing they still have links to the smaller drone market, eHang has signed agreements with DHL to fly packages along an eight-kilometer (five mile) route between a customer site and DHL’s service center in Liaobu, Dongguan, Guangdong Province.  EHang’s new Falcon series will reduce one-way delivery time from 40 ground minutes to only eight minutes, with cost savings of up to 80 percent per delivery.

eHang certainly seems driven to explore new ways to use their technology.  With an ongoing program of showing those capabilities to the world, they will probably surprise us many more times.


CES 2020: eVTOLs Vie for Attention

Two electric Vertical Take Off and Landing (eVTOL) craft captured spectators’ attention at the 2020 CES (Consumer Electronics Show) in Las Vegas, Nevada.   Mick Akers of the Review-Journal reported on Bell’s Nexus 4EX, an updated prototype or the concept machine they showed last year, and the New Hyundai SA-1, unveiled as part of its partnership with Uber.

The Bell Nexus 4EX

Akers reports, “After lighting up CES 2019 with its Nexus vertical takeoff and landing aircraft model, Bell returned this year with an updated prototype: the Nexus 4EX.”

Unlike last year’s hybrid version, the 4EX will be fully electric.  Akers noted that, “the 4EX features four fan ducts, a reduction from the six shown with last year’s model.”

Bell promotes the benefit more marketers in the UAM segment are attacking – time.  “Your commute, transformed.  Turn a 45-minute drive into a 10-minute flight. The safe, convenient Air Taxi is designed to let you make the most of your commute. Its sleek cabin offers a comfortable space for you to relax. Or work. Or socialize. All while saving your most precious resource: time.”  If you have a pressing need to fly at 150 mph within a 60-mile radius, the Nexus will get you there quickly.

Akers added, “Bell brought along mini drone versions of the Nexus 4EX model and flew them around a miniature city to display how the system would work.”

Mitch Synder, CEO and president of Bell, explains the more expansive plans that “system” would entail.  “With focus on the passenger experience, we revealed the technology and the vehicle that will revolutionize transportation in cities at CES 2019. This year we’re demonstrating what governing, operating, working and living in a smart city will look like.”

Smart aircraft and cities will require smart software, so Bell is partnering with Microsoft Azure on which the Bell AerOS system will run.   According to Akers, “The service was created to manage fleet information, observe aircraft health and manage throughput of goods, product and predictive data and maintenance.”

Hyundai SA-1

Doubling down on Bell’s four rotors (appropriate in Las Vegas), Hyundai’s SA-1 features four tilt rotors and four lift rotors.

Duplicating Bell’s payload with four passengers and a pilot, the SA-1 is a largish 35 feet long, with its 7,000 pound gross weight carried not just on eight rotors, but wing of almost 50 feet.

Close to the Bell’s performance, the SA-1 cruises at 150 mph, with a top cruising speed of 180 mph possible. 100 percent-electric, the sky taxi can fly 63 miles.  Most craft designed within Uber’s parameters will have similar performance.

Recently recruited after a 30-year career with NASA, Jaiwon Shin, executive vice president and head of Hyundai’s Urban Mobility Division, says, “Our vision of Urban Air Mobility will transform the concept of urban transportation.  We expect UAM to vitalize urban communities and provide more quality time to people.”

Big Two Dominate, But Others Chime In

The transformative possibilities of UAMs will not be possible without ground-based support systems.  Bell and Hyundai had exhibits glorifying their approaches to meeting this need, and the National Business Aviation Association (NBAA) comments on this.

Headlined, “Urban Air Mobility Dominates Headlines at CES 2020,” the organization explains that as a followup to its Nexus vehicles from 2019 and 2020, Bell showed off AerOS.   They describe is as,“A digital fleet management mobility platform designed to assist eVTOL operators and cities with the complicated task of integrating UAM into the ‘vertical landscape’ over metropolitan areas.”

In a Bell Nexus City display, scale models of the 4EX and their autonomous pod transport cargo delivery vehicle lifted off and landed on rooftops as they would in reality, managed by the AerOS platform.

Hyundai’s approach is a bit more integrated.  Their “smart mobility solution” includes the Hub, linking the S-A1 and other UAM aircraft to Hyundai’s Purpose-Built Vehicle (PBV), an autonomous ground transporter offering customized onboard dining, retail or medical service options.  The Hub, a modular system, provides docking not only for the aircraft, but for many types of PBVs that seem to be possible.

Linked to the hub, a variety of PBVs would haul people or cargo and even charge the other vehicles.

“Hyundai is our first vehicle partner with experience of manufacturing passenger cars on a global scale,” said Uber Elevate’s Eric Allison. “Combining Hyundai’s manufacturing muscle with Uber’s technology platform represents a giant leap forward for launching a vibrant air taxi network in the coming years.”

Uber Air

Uber had presented three design concepts to manufacturers for aerial vehicles which would suit its Elevate program.  Bell, Hyundai, and five others are working on delivering these vehicles so Uber Air can fly them commercially in Los Angeles, Dallas and Melbourne, Australia by 2023.

Uber has been flying conventional helicopters in New York City as a demonstration of how the program would work.  According to the NBAA, “The service would be carried out by creating skyports, which would be placed in high volume areas of cities, where up to 1,000 landings per hour could occur, according to Uber Elevate’s website.”  See also the White Paper Uber released in 2016 on its anticipated part in urban mobility.

Yolanka Wulff, Co Executive Director at Community Air Mobility Initiative (CAMI), echos this idea.”Urban air mobility will have to be properly integrated into existing and future metro, bus, and other transit options for the full-trip time savings of taking to the air to be realized.”  CAMI is working with state and local jurisdictions to solve these issues.

More to Come

This blog will cover more of the ground-based support systems for the potential UAM boom.  Report on two architects who designed Uber Elevate Skyports, a realtor who has developed an exurban neighborhood that would be friendly to fixed or rotary-winged aircraft, we will look at the potential for longer-range UAMs to support a different way to commute.


Bye Aerospace Expands Its Horizons

Bye Aerospace has been making inroads into both battery development and flight training with partners on an international scale.

 Alliance with Oxis Energy

As reported in July, Bye Aerospace and OXIS Energy announced a collaborative program to achieve a 50-to 100-percent increase in flight time from a single charge compared to existing batteries.  On its web site, OXIS reveals that it is, “…developing a <30 kWh battery system integrated with an Aviation Battery Management System for a two-seater electric passenger aircraft.”  The partnership, “…seeks to achieve a 50% to 100% increase in flight time from a single charge on future Bye Aerospace eAircraft,” with cells exceeding 500 Watt-hours per kilogram at 20 Amp-hour capacity.  This will lead to weight reduction and increased flight duration.


Quantum Air, OSM and Bye Form a Synergistic Enterprise

Quantum Air is a short-range carrier with a mission.  “Our mission is simple and prevalent throughout our brands.  To change the way people travel through cutting-edge aeronautics, made available to the general public in a cleaner, safer, and more exhilarating way than ever before. We invite a future where on-demand air travel is as ubiquitous as car service, a future where our aircrafts consume half the fuel but generate twice the excitement, a future where you don’t have to go through 2+ hours of travel, check-in, and security for a 45-minute flight.

Quantum relies on OSM Aviation, a 6,000 person operation that has trained pilots since 1963, to provide training for its pilots.  Both will use eFlyer all-electric aircraft, and have ordered a total of “160 zero-emission aircraft with significantly lower noise pollution and enhanced altitude performance” to be delivered by the end of 2021.

OSM will train future pilots who will fly the Bye eFlyer 4 for Quantum Air.  Like the eFlyer 2, it will have Rolls-Royce power

Tony Thompson, founder and CEO of Quantum, sees the benefits of this approach. “Quantum’s partnership with OSM means that Quantum pilots will fly commercially in essentially the same aircraft in which they trained.  Quantum commercial pilots will be intimately familiar with their aircraft, setting a new standard for safety.”

Espen Høiby, CEO of OSM Aviation Group, adds, “Air travel is instrumental in bringing people together both regionally and internationally. Since humans will always have the urge to explore this world, we need to find sustainable solutions to meet that need.  Therefore, OSM Aviation is excited to join forces with Quantum Air to shape a greener and safer aviation industry in the years to come.”  OSM operates training operations in Norway, Sweden and the United States of America.

Scott Akina, Quantum’s Vice President and Chief Pilot, agrees, explaining, “I expect to receive pilots from OSM who will already know Quantum’s aircraft systems inside and out, and this will be no small part of the reason why Quantum will run the safest operation in the airline industry.”

George Bye, CEO of Bye Aerospace, said he is impressed with the collaborative partnership between OSM and Quantum. “Electric aviation, including our eFlyer family of electric aircraft, is the springboard for a movement that we believe will breathe new life into the aviation industry,” he said. “That includes implementing creative ways to improve effective, economic access to pilot training. The OSM-Quantum model, which focuses foremost on new professional pilot training safety, aligns perfectly with Bye Aerospace’s principles.”

 Quantum Air’s Electrified Goal

Contending for the honor with Harbour Air in Canada, Quantum Air strives to become the world’s first all-electric airline, “disrupting the regional air travel sector with an environmentally friendly and lucrative alternative for travelers.”

Their web site suggests they will offer intra-city, inter-city and even sub-orbital options to their clients.  They are positioning themselves to be environmentally friendly in all realms, with craft such as the Surefly (below) and the Bye range of two- and four-seat eFlyers.

Bye Aerospace’s Success So Far

George Bye has positioned his company to be a leader in training and cross-country electric aircraft.  If his partnership with OXIS can bring about the 2X batteries and greater safety promised by its design, electric trainers and passenger-carrying light aircraft could be competitive with their fossil-fueled cousins.  With the training and operational partners now formulating their plans, we look forward to their making aviation more sustainable, affordable, and accessible.

Thank you’s to Diane Simard, VP of Bye Aerospace and Beth Stanton of the EAA for calling these developments to your editor’s attention.