Making Silicon Anodes in Large Batches

A Long-term Collaboration

Dr. Jaephil Cho is a well-known battery researcher and inter-continental associate of Dr. Yi Cui of Stanford University.  The pair has collaborated on many ways to improve battery performance and longevity, and both have appeared at various electric aircraft symposia.  They have even inspired others in related research. Dr. Cho and his team at Ulsan National Institute of Science and Technology (UNIST) in South Korea announced a way to make a new generation battery anode material – a big move toward mass production of improved cells.

Dr. Cho’s team of researchers affiliated with Ulsan National Institute of Science and Technology (UNIST), South Korea, claims to have made yet another step towards finding a solution to accelerate the commercialization of silicon anodes for Lithium-ion batteries.

A Next-generation Hybrid Anode

As reported by UNIST, “Prof. Cho and his research team have developed a new type anode material that would be used in place of a conventional graphite anode, which they claim will lead to lighter and longer-lasting batteries for everything from personal devices to electric vehicles.”

While many of Dr. Cui's batteries and components look like various fruits, Dr. Cho's looks more like a malted milk ball (editor's perspective)

While many of Dr. Cui’s batteries and components look like various fruits, Dr. Cho’s looks more like a malted milk ball (editor’s perspective)

A next-generation hybrid anode using silicon-nanolayer-embedded graphite/carbon suffered many of the problems associated with the use of silicon as an active material in batteries. The material is great at soaking in lithium during charging, and releasing it during discharge.  This repeated expansion and contraction of the silicon causes it to crumble over time, diminishing and finally destroying the battery’s performance.  Such structural failures occur with silicon particles made by conventional mechanical milling.

Drs. Cui and Cho have developed various approaches that ended up looking like fruits or other organic materials, copying nature in their structure.  Interestingly, this structure looks more like a malted milk ball to your editor.

660 Pounds in Six Hours

A newly-developed anode material has been manufactured with an increase in graphite content in composite by 45 percent. The research team even developed new equipment capable of producing 300 kilograms (660 pounds) in six hours per batch using a small amount of silane gas (SiH4), a simple procedure expected to ensure a competitive price.  Industrial-size outputs at this stage of development seem to show a clear path to commercialization.

According to UNIST, “They report that the silicon/graphite composite is mass-producible and it has superior battery performances with industrial electrode density, high areal capacity, and low amounts of binder.”

This work has been supported by the IT R&D program of the Ministry of Trade, Industry & Energy (MOTIE) and Korea Evaluation Institute of Industrial Technology (KEIT), 2016 Research Fund of UNIST, and by the Office of Vehicle Technologies, Battery Materials Research Program of the US Department of Energy.

Minseong Ko, Sujong Chae, Jiyoung Ma, Namhyung Kim, Hyun-Wook Lee, Yi Cui, and Jaephil Cho published “Scalable synthesis of silicon-nanolayer-embedded graphite for high-energy lithium-ion batteries,” in the August, 2016 issue of Nature Energy.


Brammo, one of the first American electric motorcycle makers, established itself as an early competitor in racing, and after less than a decade in the new arena, sold the motorcycle racing enterprise to Polaris Industries Inc.  “Following that announcement, Brammo confirms its exclusive agreement to supply its electric powertrains to Polaris for inclusion in motorcycles and other on-road and off-road vehicles.”range of vehicle OEMs.”

From Motorcycles to Helicopters

Surprisingly, that range of vehicle OEMs includes a successful electric helicopter launch.

According to the Portland Business Journal, “Brammo lent its expertise to a Tier 1 Engineering launch of a battery-powered manned helicopter last month. The launch included the first hover taxi and a record five-minute cruise flight to 400 feet altitude.”

Dual motors allow flight even if one fails

Dual motors allow flight even if one fails

Tier 1 describes itself as “A provider of engineering services, specializing in lightweight composite structures. We offer engineering design and build services to the Aerospace, Energy, Marine, Medical, and Consumer Product sectors. We handle all projects in a secure environment to protect client privacy and follow AS9100-compliant quality practices.”

Teir 1’s President Glen Dromgoole, reports the September 21 flight at Los Alamitos Army Airfield in California, included a vertical takeoff, cruise and landing based solely on battery power.”

Brammo's 1,100-pound battery pack contributes to 2,500 pound gross weight

Brammo’s 1,100-pound battery pack contributes to 2,500 pound gross weight

Brammo contributed 1,100 pounds of lithium polymer batteries (approximately the weight of a Tesla S battery pack) to the effort, which included twin electric motors and a control system from Rinehart Motion Systems.

The craft flew for five minutes on an oval course around the field, and landed with about 80-percent of the pack’s energy remaining.  It will be interesting to see future flights with greater altitudes and/or endurance.

Tier 1 reports, “Lung Biotechnology PBC intends to apply the EPSAROD technology to distributing manufactured organs for transplantation to major hospitals with much less noise and carbon footprint than current technology.  Tier 1 Engineering is an aircraft design and development company with operations in Costa Mesa, California, and Victoria, Australia.”

Previous Attempt

In 2010, Sikorsky showed an electric Firefly™, a battery-powered S-3000 which swapped the original gasoline engine for an electric motor and two 45-kilowatt-hour Lithium Technology Corporation Gaia battery packs.  These were intended to power a 190-horsepower electric motor, but it’s unsure whether the helicopter ever flew under battery power.

Tier1’s Specifications and Potential

The converted Robertson R44 helicopter has a gross weight of 2,500 pounds, complete with a Brammo battery pack weighing 1,100 pounds.  Although unchanged from a standard R44, the craft has a digital cockpit display to allow pilot management of torque and power.  It also provides data logging.

The machine has an estimated endurance of 20 minutes, or approximately 30 nautical miles of range.  As with all such projects, the developers hope to obtain higher energy density batteries.  A nine-person team took six months to bring the craft to its present state, removed the original Lycoming IO-540 engine, and replaced it with two electric motors and a reduction gearbox in a custom installation, and devised a large, under-aircraft mount for the 11 battery modules.

Although the term “semi-autonomous” appears in the acronym “EPSAROD,” there are no such features in the current version.  “The purpose of the aircraft is to demonstrate the feasibility of battery-powered VTOL and cruise for a manned helicopter.  Semi-autonomous avionics, navigation and controls will be implemented later in the EPSAROD development program. The ultimate goal of the EPSAROD Program is to produce electric-powered semi-autonomous aircraft that are capable of distributing manufactured organs to hospitals for transplantation,” according to Tier1.

Eventually, with better batteries, of course, the helicopter could carry two people and three“manufactured organs with a total payload weight of 600 pounds for not less than 150 minutes, including a 30-minute reserve.”

Look for ongoing flight tests and a more advanced vehicle due in late 2017.


Outback Joe goes through a lot of trauma in his overstuffed life.  This literal straw man gets tossed into some remote part of the Australian outback every year and waits for some kind of rescue.  This usually comes by air, drones searching for him and taking him medicine, food, water, or some other necessity.  That’s the Outback Challenge.

UAV Challenge teams for 2016, showing a wide (wild) range of configurations

UAV Challenge teams for 2016, showing a wide (wild) range of configurations

One can see a condensed history of the competition from its inception in 2007 to today on Wikipedia, the entry including the different kinds of things Outback Joe needed for a mission to be successful.

This year, however, competitors were supposed to bring back a reminder of their visit to Joe – a blood sample – a good trick from an inanimate being who might answer to “Hay!”

Outback Joe in typically relaxed pose, awaiting delivery of life-saving materials. This is from 2014 contest

Outback Joe in typically relaxed pose, awaiting delivery of life-saving materials. This is from 2014 contest

Richard Glassock, now a Research Fellow at the Institute for Aerospace Technology, the University of Nottingham, describes the vision and how it has grown up.

“The competition Rod Walker and I first discussed about 16 years ago has matured into something really worthwhile. We ran the first one in 2007, and the most recent event realizes much of the initial vision. Originally I wanted to deliver pizza and beer, but the medical emergency rescue theme is clearly of more immediate value.”

According to, ten teams qualified for the event:

  • CanberraUAV (Australia) West Coast UAV (Australia)
  • UNSW Canberra UAV Team (Australia)
  • Monash Unmanned Aerial Systems (Australia)
  • PerthUAV (Australia)
  • Forward Robotics (Canada)
  • MelAvio (Poland)
  • ArsNumerika-JetStream (Poland)
  • MAVLab TU Delft (The Netherlands)
  • ISAAC UAV, Kasetsart University (Thailand)
  • Airborne Delivery Challenge

Day One

Richard reported on the progress for the event, with Day One devoted to scrutineering the ten entries, assuring that all participants met the requirements for the event.  The Ars Numerica entry from Poland, the Jet Stream, was held up in customs and passed technical review the next day.

Following are three videos of the checks necessary to assure smooth running (fate aside) for a successful Outback run.  The first shows the Canberra effort, the second the Monash, and the third the Polish JetStream.  All are serious machines with extremely smooth control when left to their own autonomous ways.

Day Two

Seven teams made the retrieval attempt (out of the eight that made it through tech review). Richard summarizes Day Two here: “There is one more day to run, but so far it appears Canberra UAV has again led the field by utilizing a Quadrotor Fixed Wing VTOL to fly the cross country mission, autonomously land, and return with the medical payload. I have always considered this to be a most viable and versatile configuration. They would have fully completed the mission and collected the $50k prize money again this year, had their relay communications platform not suffered an engine failure. The gas powered helicopter had to make an autorotation forced landing. Perhaps a hybrid-electric powerplant would have provided the necessary power and endurance while giving sufficient redundancy to complete the mission? In any case, it was an excellent and successful result overall demonstrating the utility of these systems for real world humanitarian applications.”

ISAAC UAV of Kasetsart University from Thailand fielded a helicopter, which unfortunately began smoking just after spotting Joe, and suffered damage in a heavy landing.

Two Perth, Australia teams came afoul of the geofencing that marked aerial boundaries, and flying outside the lines disqualified one of them.

Delft Technical University’s Delftacopter – which the team described as a “Delta-wing Electric Longrange Transitioning Autonomous Helicopter” showed great promise, looking a great deal like JoeBen Bevirt’s power kite systems of five years ago.  Fate intervened during a good run, though, and Delftacopter was snared in a very tall tree.

Competitors could use a kind of “tag team” approach, fielding one craft as a spotter and the other to retrieve Joe’s sample.  Monash University had a helicopter to speedily find Joe, but that lost power and autorated to a punishing landing.

Day Three and Results

UAV Challenge final scores. See UAV Challenge web site for details

UAV Challenge final scores. See UAV Challenge web site for details

The UAV Challenge site reports on the final day.  “Canberra UAV were clearly first on points but did not complete the Challenge as their support aircraft crashed at the farm. But they did return the blood sample and this was a massive achievement and something that the organizers had not expected in the first running of the Medical Express event. Congratulations to them.”

Delft had perhaps the most dangerous part of the mission, retrieving their aircraft from that very tall tree.  “MAVLab TUDelft came second using their very new type of aircraft – the Delftacopter. They even managed to recover it from the very high tree at the end of the flying day yesterday, and so they were quite happy.”

The High School Airborne Delivery Challenge

A related event, the Airborne Delivery Challenge, open to high school teams, had a good number of entries and a variety of innovative approaches.

Palmdale High School students won the Delivery Challenge

Knight High School students from Palmdale, California won the Delivery Challenge

According to the organizers, “Phantom Soldiers, a team from the Knight High School in Palmdale, California, has won the 2016 Airborne Delivery Challenge and $5,000. It was a great contest but the accuracy of Phantom Soldiers’ drops was incredible and they won by more than 10 points. All three of their medical packages also landed next to Outback Joe with an impact force under 75G (the requirement to gain maximum points). It seems that their innovative drop mechanism and packaging were one of the secrets of their success.”

The level of creativity and competitiveness shows the ongoing progress in airframe design, sometimes complex power design, and a growing capability of autonomous controls.  It might be only a few Outback Challenges away before we see Joe airlifted to safety, while enjoying a slice of pizza and a pint of Foster’s Lager.


Brian Carpenter’s EMG-6 Webinar

Brian Carpenter, designer of the EMG-6 motorglider which he’s shown over the last several years at AirVenture, will stage a webinar to discuss “the design and development concepts of this new electric motorglider.”  His talk will have special “Emphasis on the integration of the electric propulsion concepts that he believes will change the face of the light aircraft and ultralight industry.”

EMG-6 with R&D motor in place

EMG-6 with R&D motor in place

Your editor has visited Brian’s Corning, California workshop several times, and always found new and innovative approaches to producing a low-cost, self-launching motorglider, with several ways to simplify construction and to power the craft.  It will be interesting to see progress on the newest motor (apparently still under development) Brian has presented on his web site.

Hydroformed rib with EAA-approved embellishment

Hydroformed rib with EAA-approved embellishment

He has been experimenting with low-budget hydroforming for making repeated metal parts and making plastic parts using 3-D printers.  His shop is always worth seeing.

To register for the session, click here.


A day after Pipistrel, the DLR and associates flew the first public demonstration of their four-seat hydrogen-powered HY4, your editor and a friend took a brief hop around the Aurora State Airport in Oregon in EAA’s Ford Trimotor, the first certified airliner in America.  The two events, roughly equal in duration, if not in historicity, demonstrate a readily observable progress in aeronautics.

HY4 is pictured at the airport in Stuttgart, Germany, Thursday, Sept. 29, 2016. (Christoph Schmidt/dpa via AP)

HY4 is pictured at the airport in Stuttgart, Germany, Thursday, Sept. 29, 2016. (Christoph Schmidt/dpa via AP)

A quickening of design and technology

14 years after the Ford 5AT first flew on a scheduled route that took 51 hours total time to cross the United States (and split transport duties with trains), your editor’s father was whisked nonstop by Army Air Corps C-54 across the Atlantic to Shannon, Ireland, and then to Bobbington and Newquay, England to work on bombers for the duration of the conflict.

Those 14 years seem like a major quickening of design and technology, which brought us pressurized cockpits, turbocharged engines, and great leaps forward in speed, endurance and reliability.

Following the war, a great number of aircraft became available to civilian flyers, many of whom had benefited from flight training during the conflict.  All those craft were essentially pre-war designs, and with few exceptions, continued as trainers and private craft for decades afterward.  Many flew behind opposed-cylinder engines also designed before the war.  Your editor learned to fly in a 65-horsepower Aeronca Champion, for instance.

Some brilliant new designs managed to find their way to market, with homebuilt aviation aficionados often duplicating existing designs, but frequently advancing the state of the art.  Burt Rutan and Dick VanGrunsven (whose Vans Aircraft factory was next to our boarding point) re-imagined design and fabrication techniques to make high performance available with the same general aviation engines used on their humbler brethren.  Even with such stellar engineering, many private airports are windows to past glory.

That experimental spirit prevailed On 29 September 2016, when the HY4 aircraft took off on its first official flight from Stuttgart Airport. The HY4 is the world’s first four-seat passenger  aircraft (the qualification is important) powered solely by a hydrogen fuel cell system. Researchers from the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) developed the aircraft’s power train and worked on the project with industry and research partners.

Using the airframe from the Green Flight Challenge winning Pipistrel G4, The HY4 fuel cell aircraft was developed by the DLR Institute of Engineering Thermodynamics together with partners Hydrogenics, Pipistrel, H2FLY, the University of Ulm and Stuttgart Airport.

One special addition to our Tri Motor outing was that Robin Reid, one of the pilots in the Green Flight Challenge G4, showed up in his 1929 Monocoach to help with day’s operations.  We had a splendid example of past aircraft piloted by a man who helped show the future of aviation.

According to DLR, their researchers “were responsible for developing the hydrogen fuel cell power train and installing it in the aircraft. The power train consists of a hydrogen storage system, a low-temperature hydrogen fuel cell and a battery. The fuel cell converts hydrogen directly into electrical energy. The only waste product from this process is water. An electric motor uses the power thus generated to propel the aircraft. A high-performance lithium battery covers peak power loads during take-off and when climbing. If the hydrogen required for the fuel cell is generated via electrolysis using power from renewable energy sources, the HY4 can fly without generating any emissions at all. The aircraft is operated by the DLR spin-off H2FLY.”

Following successful flight, happy team surrounds HY4

Following successful flight, happy team surrounds HY4

The airplane is a direct “descendant” of the Pipistrel G4, but replaces the large battery pack with a hydrogen fuel cell power system.  Each pod and boom fuselage contains a pressurized tank (437 bar or 6,338 psi) holding nine kilograms (19.8 pounds) of hydrogen – enough for 750 kilometers (465 miles).  Liquid hydrogen could extend that range to 1,500 kilometers (930 miles).  In a small country like Germany, with refill points in close proximity, this would make H2 a plausible fuel for air travel.  For larger countries, or continents, the level of difficulty might also grow.

Four fuel cell modules in the center engine pod would produce 45 kilowatts, and coupled with the 21 kilowatt-hour battery, generate enough power to make the 80 kilowatt motor propel the airplane.  The lithium battery works only at peak loads.

Elevating electric drives to the next level

The consortium of enterprise and academia envisions a brilliant future for HY4-type aircraft as air cabs, linking to ground transport at strategic hubs.  “Professor André Thess, Director of the DLR Institute of Engineering Thermodynamics, said: ‘The four-seat electrical aircraft Hy4 is a perfect fit to our strategy of exploring synergy effects between electrical transport means on the road and in the air’ because electrical engines would be very well suited for shorter distances. They are low on noise and other emissions and can take off and land even on small airstrips because of their high torque. Bernd Pitschak, CEO of Hydrogenics, added that the intention was to elevate ‘electric drives to the next level.’”

A press of reporters and camera operators descends on HY4

A press of reporters and camera operators descends on HY4

H2Fly will operate the HY4, make improvements as needed, and make sure “that research and technology work hand in hand” with the aim of fulfilling Kallo’s vision of transporting more than one pilot and three passengers with this clean technology.

The Ford Trimotor was capable of lifting 15 people (two pilots and 13 passengers), although the EAA limits the payload to ten passengers.  The 420-horsepower Pratt & Whitney Wasp radial engines were the epitome of engine design for their day.  What might a similar electric/fuel cell craft look like today with improved aerodynamics and next-generation power plants?

Technology keeps pushing ahead, but your editor reflected following his flight, on the need to develop rules and standards that stay ahead of that technology.  Passengers looking down on Meteor Crater in Arizona would have been surprised to see another airplane sharing the view.  Today, especially in urban areas, we will need approaches (being developed) that keep us in the air and out of each other’s way.

Experiencing the rattle of the three exceptionally smooth, but still noisy engines brought to mind neighborhood groups that invariably form around the disturbance that arrivals and departures bring with them.  Robin Reid’s mother Amelia, for instance, spent many hours fighting to keep Reid-Hillview Airport operational as the once-rural landscape was covered in clusters of houses and shopping malls.  Quiet transit will be a prerequisite to entry at tomorrow’s airports.  Even with the advances made by the latest versions of popular airliners, electric craft will bring blessed relief to nearby households and businesses.

Our 15 minutes aboard the ancient Ford gave a glimpse of past glory, and the 10-minute demonstration in Stuttgart shows at least one possibility for green aviation.  Just as the best technology of the past forced creation of regulations to make commercial aviation what it is today, new technology – often a product of visionary minds – will require visionary planning and regulatory wisdom to help it fulfill its promise.


Take a venturesome electric car developer like Venturi, a Monaco-based firm, and put them together with an enthusiastic group of Ohio State University engineering students.  Exciting things happen.

Ohio State Buckeyes/Venturi VBB-3 with 3,000 horsepower ready to roll quickly

Ohio State Buckeyes/Venturi VBB-3 with 3,000 horsepower ready to roll quickly

The Buckeyes have tried their hands at racing in many venues.  Their first outing in the 2013 Isle of Man Tourist Trophy Zero gained them a third place finish – followed by another third place outing in 2014, and their tour of the Pikes Peak International Hill Climb this year took a mere 11 minutes and 16 seconds, good enough for third place.  They also race in the Formula SAE competition, putting their open-wheel, high-performance cars up against those from 110 other colleges and universities.

Ohio State Racing team, Driver Roger Schroer at the nose. Multi-discipline team made speed records possible

Ohio State Racing team, Driver Roger Schroer at the nose. Multi-discipline team made speed records possible

Turning their eyes from the curves of the Isle of Man and Pikes Peak, to possibly the flattest place in America, the Buckeyes came in first this time, setting a world record 341 mph with their Venturi VBB-3, all 3,000 horsepower engaged.

In fact, the team set two land speed records at the Bonneville salt flats in Utah – the two-way average speed required for a record, and a one-way run of 358 mph.

Inner workings - mostly batteries - propel VBB-3 to record speeds

Inner workings – mostly batteries – propel VBB-3 to record speeds

As the team reports, “After three years of battling difficult weather conditions at the Wendover, Utah, Bonneville Salt Flats track, The Ohio State University’s Venturi Buckeye Bullet 3 student team and driver Roger Schroer rallied to push their electric streamline vehicle to a world record two-way average top speed of 341.4 miles per hour (549.4 kilometers per hour) on Monday, Sept. 19, 2016.

“The Venturi Buckeye Bullet 3 (VBB-3) shattered the previous world record of 307.6 mph (495 kph), set by the Ohio State-Venturi team in 2010. The new world record is pending certification by the Federation Internationale de l’Automobile (FIA), the worldwide motorsports governing body, in Category A Group VIII Class 8.”

Venturi delves into many aspects of exotic concept cars, and even formula e competition.

“Venturi is an electric powertrain manufacturer headquartered in Monaco. It set its first world land speed record in 2009 with a fuel cell powered car that recorded a speed of 487 miles per hour. After that, the company switched its efforts to battery power and enlisted the aid of Ohio State. In 2010, its first battery racer — VBB 2.5 — was driven by Roger Schroer t0 a top speed of 495 miles per hour. S’chroer was back behind the wheel for this year’s record setting attempt.

“Each time I enjoyed driving the car and achieving this performance. But at those speeds you have to focus on your task not on your emotions. I know we can go further. This week the track was good. No main vehicle instability. Much better than the last days during tuning and testing. We always have to be patient and wait for the track to be ready,” said Schroer.”

Combining the talents of a multidiscipline team of university students and an environmentally-conscious automotive firm has helped achieve sterling results this year.  We eagerly anticipate where these trend-setters in aerodynamics, electronics, and mechanical applications go next.  Who knows, maybe they’ll race at Monte Carlo next year.


Acentiss’ New Dual-Redundant Motor

Acentiss is a German engineering and consulting firm specializing in medicine, aerodynamics, and recently, the creation of two small electric motors for light aircraft.  Located almost symbolically between Robert Koch Strasse (Nobel Prize in Medicine) Max Plank Strasse (Nobel in Physics), and EinsteinStrasse (Nobel in Physics) in Ottobrunn, the company not only provides design services for wind turbines and their components, assistance with process flows for the manufacture of medical equipment and devices, and consultancy services for the automotive and aeronautical industries, but has created components for use on light aircraft and unpiloted aerial systems.

Acentiss dual-rotor unit as shown at 2016 Aero Expo at Friedrichshafen

Acentiss dual-rotor unit as shown at 2016 Aero Expo at Friedrichshafen

Their motors, developed with assistance from Geiger Engineering, look a great deal like the HP-25D from that company, often seen flying on PC-Aero aircraft.  The two motors, both 218 millimeter (8.6 inches) in diameter, produce a maximum of 32 kilowatts (42.8 horsepower) or 40 kW (53.6 hp).  The smaller motor can produce 25 kW (33.5 hp.) continuously at a leisurely 1,950 rpm, and the larger (thicker) motor can generate 32 kW at 2,200 rpm.  Both motors run at 58 Volts, meaning a high amperage helps create the torque to turn a propeller at low rpms.  Many think low voltages will provide greater safety for operators.

The less powerful motor weighs 8.9 kilograms (19.6 pounds) and the more powerful 11 kilos (24.2 pounds).  This light weight, coupled with the weight of the recommended dual motor controllers from Geiger Engineering that weigh only one kilo (2.2 pounds) each

Tandem rotors on both power plants can run independently, the same as those on the Geiger HP-25D, enabling economical flight on one rotor, or a “get-home” mode at half power that will at least stretch the glide in the event of one rotor or controller failing.

Elias, Acentiss' modified Elektra One, showing electric retractable landing gear

Elias, Acentiss’ modified Elektra One, showing electric retractable landing gear

Acentiss is flying the motor on a modified PC-Aero Elektra One, but one which mounts Acentiss’ retractable tricycle landing gear.  For surveillance operations, The Acentiss Elias pulls the gear inside the fuselage for the nose wheel, and inside the wings for the main wheels, making an unobstructed view for belly-mounted cameras and sensors.  The gear weighs only 22 kilograms (48.4 pounds), a creditable weight for something that allows higher performance for an already clean airframe.  Solar cells can extend the airplane’s range and endurance.

11-meter span is readily apparent in this view

11-meter span is readily apparent in this view

The 11-meter (36-foot) span, 320 kilogram (704 pound) craft can carry batteries sufficient for 1.5 hours’ endurance, and significant test gear that can be monitored by an Acentiss Ground Control Station (GCS).  Depending on whether a pilot is on board, the system can monitor and control, by visual or data transmissions, the mission based on pre-set plans or manual over-rides.  It can check the multi-spectral, high-definition sensors on board Elias and record their output.

Beyond the interesting pair of new motors, Acentiss, with its many fingers in many technological pies, may pull out a surprising number of plums in the near future.


Solar Ships Deliver the Goods

People in remote areas of Africa may find relief coming quickly to disaster zones with Manaf Freighters’ purchase of four Solar Ship aircraft.

Solar Ship’s Uniquely Hybrid Form

Solar Ship, located in Toronto, Canada, builds solar-powered triangular, blimp-like flying machines that could serve as lifelines to the world’s most remote places.  Solar Ships range from an 11-meter wide (it’s hard to call it a wingspan) envelope to a projected 100-meter (328 feet) wide monster that could carry up to 30,000 kilograms (66,000 pounds) for a minimum of 2,000 kilometers (1,240 miles).

The blog reported on Solar Ships three years ago, when their few flying examples were testbeds for the possible future development of practical load haulers.  Combining buoyancy with aerodynamic lift allows large payloads and great short-field performance, making their craft viable “bush” planes.  That the company can now build larger craft will demonstrate their concept to a wider audience.

With operations based in Ontario, Canada; Cape Town South Africa; Lusaka, Zambia; Kampala, Uganda; and Shenzen, China, Solar Ships is located near many already isolated spots which have the potential to become even more cut off.  The craft’s “lifting capacity of a truck and the performance of a bush plane” make it well suited to rescue and supply efforts by the humanitarian organizations that will use these unique machines.

Manaf: Serving up to 400 Million People

Manaf explains its mission this way: “Located in Nairobi, Bukavu and Bujumbura, Manaf uses bush planes to service the interior of Africa, an area with a population of 400 million people and rapid growth. Flying into remote areas in the DRC, South Sudan, Uganda, Rwanda, Burundi, and Tanzania, Manaf works with local entrepreneurs, UN agencies and NGOs to bring food and medical supplies to people who do not have regular access to cargo services.”

Solar Ship prototypes in hangar, showing innovative approaches to basic configuration

Solar Ship prototypes in hangar, showing innovative approaches to basic configuration

This week’s purchase of two Caracal and two Wolverine aircraft will give the Solarship/Manaf venture extremely short takeoff and landing (XSTOL) capabilities, allowing them to use areas as small as soccer fields.  These will “be used for cargo delivery and disaster relief in remote areas in East and Central Africa,” according to Manaf.  The joint venture, Peace and Freedom Services, will be able to haul small loads with the Caracals, while the two Wolverines can carry a 20-foot shipping container with a minimum payload of five tons.

Manaf CEO Fred Nimubona sees an existing need based on the harsh conditions in the regions served in conflict zones.  “The need for Peace & Freedom Services is immediate in our region. Many lives are being lost and our joint venture promises to improve the quality of life in regions that have, up until now, been inaccessible or diminished by war.” 

Prototype Solar Ship in flight, showing inflatable wing which adds buoyancy to aerodynamic lift

Prototype Solar Ship in flight, showing inflatable wing which adds buoyancy to aerodynamic lift

Being able to drop that amount of cargo into a constrained space expands the scope of what relief services can accomplish.  Combining the airships with the two DC-3s purchased by Manaf gives a full range of capabilities and the ability to retrieve cargo from a reasonable distance for the older cargo aircraft, deliver it to a central airport, then disperse it to otherwise unserved points in East and Central Africa.  Bringing “critical cargo: food, clothing, medical supplies, and basic necessities” to hard-hit regions could aid thousands who might otherwise suffer privation and even death.

With solar-powered missions of mercy already part of Solar Ship’s future, perhaps a broader use might come from commercial hauling, with the potential to lower freight costs and speed deliveries, even at their leisurely cruise speeds.  As part of their outlook on “innovative disruption,” the company sees applications in service to environmental and scientific work.  Those willing to look beyond the ungainly appearance of these fat delta-winged hybrids might be well rewarded for their choice of an unusual approach.


Gamera: the First Solar-Powered Helicopter

Solar Gamera, an extension of the human-powered helicopter that achieved the longest HPH duration flight in 2013, just made the first solar-powered helicopter flight.  In 2014, a group of undergraduate students at the University of Maryland turned Team Gamera into Solar Gamera, “to test the feasibility of applying solar power in achieving human helicopter flight.”

Ph.D. student William Staruk, a member of the original HPH team, reflected, “Today you are seeing the first successful flights of the Gamera Solar-Powered Helicopter. You are seeing aviation history being made in the history of green aviation and rotary blade aviation.”

Gamera’s lattice-work framework, 100-foot square with extremely large rotors at the ends of four beams, carried materials science major Michelle Mahon on two short flights.  The best effort lasted nine seconds and gained an altitude over a foot.

Staruk explained, “It’s just a matter of drift before [Solar Gamera] gets longer flights.  It’s easier to trim than human-powered helicopter thanks to electronic controls.”

Note the mechanical complexities in the original human-powered version, including the “lost-string” technique pioneered by Paul MacCready.  The electric version is less mechanically extreme, with software taking over some of the functions originally managed by a Rube Goldberg arrangement.

The flight had students and advisers extolling the virtues of the project.  Distinguished Professor and Gamera faculty advisor Inderjit Chopra beamed.  “This is about inspiring and educating students, that’s our product here.  No one thought that solar energy could lift a person [via helicopter].”

Gamera 2015-2016 team lead Anthony Prete (B.S. ’16) said, “When I started this, I had no idea what I wanted to do with my engineering degree.  This experience focused me into something, design.”

The project has been active form more than six years and involved more than a hundred students from across the Clark School in a project most would never have envisioned in their high-school years.

“’This project has come a long way in the past six or seven years from human-power to solar-power,’ added Staruk. ‘So we are breaking barriers of all sorts in aviation with this one airframe and we are very proud of that work here at the University of Maryland.’”

Competition from Toronto

In 2013 AeroVelo’s “Atlas” won the prestigious $250,000 Igor I. Sikorsky Prize from the American Helicopter Society by reaching an altitude of 3.3 meters (10.8 feet)  under the pilot’s (Reichert’s) own power, and hovering for 64 seconds.   Although Gamera missed the gold, it achieved several subsequent records as noted above.

A Proud Cinematic Heritage

Cinematic superstar Gamera may soon re-appear on the big screen

Cinematic superstar Gamera may soon re-appear on the big screen

Gamera is named after a movie-star turtle, a large, pugnacious, flying, fire-spouting testudine created by Daiei Studios to compete with  Toho Studio’s ever-popularGodzilla.  Gamera turned out to be less destructive than the competition and even protected children in his films.  A note of hope for Japanese rubber monster fans: a new version of Gamera is scheduled for release soon.


e-Genius Flies with a Range Extender

Stuttgart to Barcelona

Dipl-Ing* Ingmar Geiß, Deputy Project Manager for e-Genius with the Institute of aeronautical engineering at Stuttgart University shared the news that e-Genius flew with its range extender for the first time on September 15.  He notes that while the battery-powered airplane can manage trips up to 300 kilometers (186 miles), the hybrid engine/generator pod will enable flights up to 1,000 kilometers (620 miles).  This would equal a trip from Stuttgart to Barcelona, Spain, according to the e-Genius web site.


e-Genius with engine/generator pod on right wing. Pod is easily attached and detached to allow flight as pure battery-powered craft

e-Genius with engine/generator pod on right wing. Pod is easily attached and detached to allow flight as pure battery-powered craft

As the school explains, “With [the] e-Genius hybrid most flights of a typical user case can be done in the cost and energy efficient battery mode – for all longer flights the range extender can be used.

Generator system control requires no pilot input, everything being done automatically.  If the pilot wants to set down at the end of a trip with a certain amount of battery energy on board, e-Genius has an ingenious “look-ahead” feature to modulate the battery to achieve the desired level at the end of the flight.

Quiet and Efficient

Already recognized as one of the quietest aircraft on record (56-62 dBa in the 2011 Green Flight Challenge), the hybrid craft takes off on battery power alone and switches the engine generator on when the airplane achieves cruise altitude.  This type of strategy makes e-Genius a good neighbor.  As Ingmar reports, “The system left an excellent impression – additional noise in the cockpit was barely hearable. So we could still enjoy our silent electric aircraft and didn’t have to use headsets.”


e-Genius climbing out on pure battery power. Internal combustion engine is turned on at altitude to avoid disturbing people below (not that they would notice any additional noise)

e-Genius climbing out on pure battery power. Internal combustion engine is turned on at altitude to avoid disturbing people below (not that they would notice any additional noise)

The blog described the hybrid engine/generator pod last year, a compact Wankel engine powering an equally compact generator while consuming only five liters per hour of fuel.  Cruising at over 100 mph, the airplane would use only one liter per 20 miles at about 75-percent power (for the engine/generator), or 1.3 gallons per hour.  Fuel consumption would doubtless go down at lower generator outputs.

Because Wankel engines tend to be thirsty, estimable reader Howard Handelman sent an excellent critique of last year’s entry, including compromises in battery-pack size, different approaches to controlling fuel usage and getting the most out of a hybrid-package.

e-Genius hybrid schematic. Pilot does not notice changes in operation, software combining outputs from alternator and batteries automatically to run motor

e-Genius hybrid schematic. Pilot does not notice changes in operation, software combining outputs from alternator and batteries automatically to run motor


A Ground-based Equivalent

Another German product, the BMW i3, has a range extender that allows one to run beyond low battery range.  One owner apparently does a lot of local driving and uses only battery power for most of his commuting.  “However, I have to admit, I thought I’d need to use the range extender more than I actually have. Of my 56,000+ miles, only 1,925 miles have been with the range extender running. I’ve bought 50 gallons of gas (I kept records) and averaged 38 miles per gallon while the range extender was running, just slightly less than the EPA rating of 39 mpg.


Tom Moloughney’s 1,000 mpg BMW 13 Rex.  It used less fuel than he drinks in coffee per month, and less tan his gardner’s tractor burns mowing his two-acre lawn each year.  Charging at home comes from the solar roof on his house

“But just how little gas is that? Well, as I’ve said, I’ve owned the car for 27 months now, so that averages out to me needing to refill the tiny 1.9 gallon gas tank about once every month — I drink more coffee than that in a month! However, refueling hasn’t been nearly that regular. I’ve gone stretches of four or five months at a time without needing to buy gas. But I’ve also taken the car on a couple of road trips of two or three hundred miles where I needed to refuel three or four times in the same day to complete the journey. In fact, the majority of my REx miles were accumulated on long trips. These trips simply wouldn’t have been possible in an i3 BEV, as charging infrastructure is only now becoming available along the routes I’ve traveled.”

Such strategies will be the source of endless speculation and controversy until batteries become energy-dense enough to allow what drivers consider “normal” trips without recharging.  Aircraft designers and builders will then have access to power sources that will allow long flights and great performance – something fairly elusive thus far except for rare aircraft such as e-Genius.

The e-Genius fuel tank holds 100 liters, so at 5 liters an hour, 16-hour flights (with reserve) would be possible – too much for any rational need other than record breaking.

*Dipl-Ing (Diplom-Ingenieur (German equivalent of M.S. degree, according to Free