Volocopter Hovers Over Stuttgart

Stuttgart sees first urban flight of Volocopter in Europe    

Volocopter has demonstrated an unmanned flight over Stuttgart, Germany on September 14, part of a two-day event titled, “Vision Smart City – Experience future mobility today.”   A major promotion of Mercedes-Benz’s history, products, and plans for future mobility, Partner Volocopter highlighted the drive toward “climate neutral mobility” by the auto maker.

Past, present and near-term future in one – Mercedes-Benz museum and Volcopter

Smart City networks will rely on Artificial Intelligence, Machine Learning and Adaptive Networks according to Ciena, a provider of networking, programming and systems for ever-increasing demands by industry and municipalities. Control of traffic that will increasingly include Urban Aerial Mobility will take intense amounts of data – up to 24 billion Internet Provider (IP) devices on earth (three for every person) and Internet of Things (IoT) gizmos  flowing up to 500 zetabytes (500 followed by 21 zeros) per year.


The Mercedes-Benz Museum featured presentations, “Of technical innovations and sustainable transport concepts for future mobility at the Mercedes-Benz Museum in Stuttgart.”  Surely, as fascinating as these papers were, there might have been an exodus to the great outdoors when Volocopter’s 18-rotor marvel passed quietly overhead.

The Minister-President of the state of Baden-Württemberg, Winfried Kretschmann, and the Chairman of the Board of Management of Daimler AG, Ola Källenius, the CEO of Volocopter GmbH, Florian Reuter, and Thomas Strobl, Minister of the Interior, Digitalisation and Migration for Baden-Württemberg, were on hand to witness this historic event.

Flying over the Mercedes-Benz Museum, the Volocopter looked down on a repository of automotive history and presented a vision of the future.  It struck a proper note as part of a research project by the Technical University of Stuttgart to examine the social acceptance of air taxis.  It surely added a realistic note to papers, exhibits and booths sharing the theme of the, “Strategic Dialogue for the Automotive Sector in Baden-Württemberg.”

Volocopter’s place on Mercedes-Benz campus shows its importance in this gathering

Ola Källenius, Chairman of the Board of Management of Daimler AG and Head of Mercedes-Benz Cars shared a surprising near-term ideal for Mercedes.  “Our partner Volocopter shows how an air taxi is turning the dream of driving into the dream of flying. At Daimler we work on the mobility of the future too. By 2022 we will have electrified the entire Mercedes-Benz portfolio. Our goal is that electrically powered cars will account for more than half of our sales by 2030. The road to climate-neutral mobility is a joint effort of companies and politics. We at Daimler a willing and ready to make our contribution.”

Winfried Kretschmann, Minister-President of the state of Baden-Württemberg. Added and element of civic pride. “I am very pleased that “Vision Smart City” shows us future mobility ideas that are already being developed in Baden-Württemberg – concepts for sustainable cities of the future, for autonomous driving and the intelligent interaction between different mobility concepts. I am particularly proud that the “Strategic Dialogue for the Automotive Sector in Baden-Württemberg” is present at the event. This dialogue between industry, science, trade unions and politics shows, that climate protection and sustainable employment is possible at the same time.”

Florian Reuter, CEO of Volocopter GmbH explained Volocopter’s role in future urban mobility.   “Our Volocopter air taxis open up a completely new dimension in urban mobility. As Stuttgart has seen today, they fly safely, quietly and are fast approching the implementation stage. Volocopter air taxis are able to ease traffic congestion in major cities around the world, also here in Germany.”

Thomas Strobl, Deputy Minister President and Minister of the Interior, Digitalisation and Migration for Baden-Württemberg concluded, “The mobility of the future must be intelligent, digital and clean, while remaining affordable. The transport concepts of major cities, medium-size towns and rural areas will certainly take different forms. There will be no universal blueprint. But we are already actively, innovatively and creatively working on mobility concepts for the future. We are the innovation region No. 1 in Europe – as demonstrated by the flight of the Volocopter and other projects presented at the event. The aim is to roll these out, and also to use the innovative strength of the municipalities.”

You can find further on the Smart City concept here.


So often, promising developments in batteries, solar cells, and electric vehicles seem stuck in the “five years from now” limbo.  Perhaps there may be hope that a current, real-time development is before us.  MSNBC reports Solid Power has a pilot production line for its solid-state batteries up and running – as of three days ago.

Forgive the sound track, which can be turned down or off.  The information is worthwhile, however.

Solid Power, a 2012 outgrowth of research performed at the University of Colorado Boulder, now holds down 21,000 square feet at the Colorado Tech Center.  Their web site expresses some of the frustration many of who have been waiting through the last decade feel about the near-static trend in lithium battery development.  “While current lithium-ion batteries continue to provide incremental improvements, the industry demands more advanced solutions capable of providing a true jump in performance thereby accelerating e-mobility.”

Solid Power might have a solution to the slow growth of battery power, and have garnered support from A123, BMW and Ford Motor Company.  Solid State’s response is an all-solid-state battery (ASSB) which replaces the liquid electrolyte in a conventional lithium-ion battery with a, “Highly stale solid ion-conducting material.”  The company claims their batteries, “Are inherently more stable across a broad temperature range while also enabling more efficient cell and pack designs as containment of a liquid is no longer required.”

More Power

Click on image to enlarge

Solid Power claims their batteries, “By simply combining a state-of-the-art cathode with a lithium metal anode, … can deliver greater than 50% more energy density compared to the best available rechargeable batteries.” Solid Power adds that by “removing flammable liquid electrolytes, we provide an inherently safer battery with a simplified cell architecture.”  Making the batteries on a roll-to-roll line similar to that used in the manufacture of conventional batteries enables ready transfer of their technology into production.

Ford has made an undisclosed investment, hoping to achieve a 50-percent better energy level than “wet” lithium batteries at the module and pack level, and simplify cooling and battery management systems.

A Production Line

Inside EVs reported a few days ago that Solid Power announced its new solid-state battery production line, ostensibly, “Fully functional and currently producing solid-state batteries.”  Even though it is just a pilot line, the company’s affiliations with Ford, BMW and A123 and their backing indicate this might be a working production line soon.

BMW’s Vision of a solid-state battery-powered future

Other investments come from Hyundai, Samsung, and a $20 million funding round in 2018.

Government Interest

Kristina Pritchett of Prariemountainmedia.com reports that on August 12, Governor Jared Polis, U. S. Senator Cory Gardner, U. S. Representative Joe Neguse and other Boulder County and Louisville notables visited the new plant.  Doug Campbell, Solid Power’s CEO expressed his pride in the facility and called it, “A big deal.”

“Our solid-state batteries provide a major improvement in energy density, safety, and reliability compared to the best lithium-ion cells available.  Together, these performance attributes can enable profound performance improvements of battery-powered devices such as electric vehicles, medical devices, aircraft, and satellites through increased run time, increased safety, and lower cost.”


Electric Flight for the Masses

Paracas, Peru lies on the South American country’s Pacific coast, halfway between Ecuador and Colombia to the north and Chile to the south.  There, Alex Ferrer has built a Super Goat ultralight glider and powered it with a Chinese motor, controller and batteries for electric flight.  Since he displays in-flight data on his videos, one can get an appreciation of the small amount of energy required to keep a very light machine like the Mike Sandlin craft in the air.

Sandlin makes plans for his gliders available for free on line.  Excellent drawings with high-grade details, they enable a committed craftsman the ability to use simple hand tools to make a glider that one can carry atop a compact car and go flying for as long as one can enjoy.  One can choose a Goat monoplane, BUG (Basic Ultralight Glider) biplane, or Bloop powered biplane.

Mike Sandlin’s drawings for the Goat are detailed enough to enable fabrication from metal tubing, fittings and fabric

According to Sandlin’s web site, the gliders share the following characteristics:

  • Folding wing design provides a large area wing in a small, light package, allowing transport & assembly by one person.
  • Center stick & rudder pedals provide a traditional control system.
  • Construction is of aluminum tubing and steel cable covered with a heat shrunk fabric.

Alex Ferrer, a sky-diving and gliding enthusiast in Paracas, built a Goat from plans and used a motor, controller and batties from Dongguan Freerchobby Co.,Ltd to power the beast.  The company makes everything from motorized skateboard wheels to large, dual motors that can drive contra-rotating propellers.

The motor, Freerchobby’s 202/80 27 brushless motor with hall sensor controller, is rated at 45 horsepower peak and 25 hp. continuous output.  Speed control comes from a Kelly KHB – High Power Opto-Isolated Brushless Motor Controller With Regeneration capabilities – meaning it can feed energy back into the batteries when the motor is windmilling.  The 8.9 pound unit complements the low mass of the 6.5-kilogram (14.3-pound) motor.  Six CNHL 8000MAH, 22.2V lithium polymer batteries help swing a 49-inch, 30-inch pitch wood propeller.

Battery packs weigh about 2.6 pounds each, or 15.6 pounds total.  The 38.8 pound power package seems not too great for the airframe, especially with a light pilot.  Pricing for these components should be around $2,500 depending on the controller’s configuration.  BUGs and Goats can be built for under $5,000, so these would be sporting machines costing less than some motorcycles or jet skis.

While eVTOLs (electric vertical takeoff and landing) machines dominate the mainstream media, many experimenters are testing the limits at the other end of the flight spectrum.  We wish Alex Ferrer the very best and will be re-visiting his YouTube page to check progress.  Since Alex has drawn on only six of the 45 reportedly available horsepower from the motor so far, self-launching seems plausible.  Such capabilities would open a new range of flight options.


Tehachapi Soars with New ideas – Day 2

The annual Experimental Soaring Association Western Workshop spills over the Labor Day weekend, starting with a welcome barbecue/potluck Friday evening and an official kickoff on Saturday.  Sunday features more technical presentations and this year  an organization business meeting and a closing talk about moon shots.

Pelicans, Albatross and Perpetual Flight

Phillip Barnes, an accomplished aerodynamicist, photographer and expert on soaring birds, links all his interests and skills in his web site, How Flies the Albatross. This year, he brought his knowledge to bear on a design for a flying machine that would pull energy from the air it flies through to power its electric motors – Coulomb Keeper. He described the design process behind it in a talk titled, “Aircraft Energy Gain from an Atmosphere in Motion.”

Keeper is an outgrowth of Phil’s earlier aircraft concept, Faraday.  Both are derived from his desire to fly like the Albatross, which manages to circumnavigate the Antarctic Circle in seemingly perpetual flight.  The bird twists its 3.5 meter (11.5 feet) span wing – the longest of any bird – in constant turns following the dynamic soaring rule:

  • Ascend when partly or fully pointed upwind.
  • Descend when partly or fully pointed downwind.

The bird pulls 2.7 g’s in the turns and maintains a high coefficient of lift of 0.7 throughout the maneuvers.  It does this repeatedly for months at a time.

Phil and a helper display life-size photo enlargement of Albatross

Phil’s knowledge of how this large soaring bird manages this inspired him to add power and conceive of a way to take a person or persons aloft on “free energy.”  His Faraday and Coulomb Keeper aircraft use large fan-like propellers designed with help from Jack Norris, an expert on the subject.

As the aircraft uses energy from batteries to ascend, it uses the windmilling propellers to recharge the batteries, much like the regenerative brakes on a Tesla or Leaf.  Coupled with a light, highly efficient airframe and slippery aerodynamic design, Phil’s craft can emulate the best that nature has to offer.

Sailplane Building In the 21st Century

A panel discussion that comprised Al Bowers, Murry Rozansky, Bob Kuykendall, Dan Rihn, Dan Armstrong,  and Tom Riley examined the many obstacles that stand in the way of soaring becoming a common sport in America.  One of these is the lack of a two-seat training craft that would bring greater appeal than those machines currently available.

Soaring is an expensive business, for starters.  Learning is costly.  One has to rent a two-seat sailplane, hire a qualified instructor, and obtain the services of a towplane and tow pilot – someone uniquely qualified to pull sailplanes to altitude.

Since these people and machines are hard to assemble in one place for just one person’s tutelage, many people, like your editor, join a soaring club, where enough qualified individuals gather.

Can homebuilt sailplanes play a part in re-invigorating the sport?  Barnaby Wainfan, an adjunct professor of aerospace engineering at the University of Michigan and Technical Fellow at Northrop Grumman, engineered such machines as the FMX-4 Facetmobile.  He suggested looking at the different production rates for Dick Van Grunsven’s RV-3 (a single-seater) and RV-4 (a two-seater).  The conclusion is that two-seat aircraft are far more popular because they allow the owner/pilot to share the ride with family and friends.  The same would be true for soaring machines.

To aid prospective builders, some suggested builder support centers, where jigs and fixtures would expedite construction, and professionals could teach builders new skills.

Meeting requirements of the 51-percent rule that dictates home builders must complete at least 51-percent of the work required on a kit can be tricky.  Getting permission to teach flying in an Amateur Experimental Built (EAB) craft might make things even trickier.

Low volume demand means that some public relations work might pay off in luring new enthusiasts to the field.  There are thrills to be had for less money and with less of a commitment in being educated in aerodynamics, piloting skills and meteorology (among other disciplines).

HP 24 Project Wrap-up

 Originally the Sailplane Homebuilder’s Association, ESA carries on that tradition, and Bob Kuykendall has been one of the most dedicated to that tradition.  His HP-24, an extension of Richard Schreder’s line of home-built sailplanes is intended for construction by amateurs.

Bob’s pricing on his HP-24 kits is low as of March 2012.  It’s probable that prices have risen in the last seven years, though, but a complete high-performance sailplane kit under $33,000 is great competition for the the much higher-priced European competitors.

Bob’s “Akafliegs” give builders a chance to use his jigs and fixtures, speed up the building process, and get assistance with all the sanding and finishing.  Eric Stewart wrote knowledgeably about the aircraft and the building sessions in Kitplanes magazine.

Bob is looking at the possibility of installing an FES (Front Electric Sustainer) in his sailplane.  This could make the HP-24 a self-launching unit or give it “save” capabilities on days of uneven lift.   Checking out the tow car (a way to keep costs down) in this video, the Citroen “Jumpy” is a 4,200 pound curb weight vehicle with 0-60 times no better than 11 seconds.  Even this modest performance enables a budget launch.

 A Certain Amount of Pull

Murry Rozansky, EAS President, followed with “Homebuilt Tow Planes, the Silver Bullets to Save Soaring.”  His premise, that alternately-powered tow planes could cut down the up-front cost of sailplane launches, certainly has merit.  Again, the problem of regulatory agencies accepting such approaches seems paramount.  Murry wrote in Plane & Pilot, “Clubs are normally cooperative noncommercial operations, so we might be able to use Experimental Amateur Built gliders for flight training. It’s common in the U.S. for club members to build their own winch. If we can convince the FAA to allow E-AB tow planes, the elements would be in place to greatly reduce the cost barriers to taking those beginning steps on the stairway to heaven.”

Apropos, a Ximango motorglider taxied up to the byard hangar mid-afternoon

Murry focused on the possibilities inherent in auto engines with their lower initial cost and possibly lower operating costs than aircraft equivalents.  Murry is a consistent and constant proponent of making soaring affordable.

Taras Kiceniuk, Icarus, and Architecture

Taras Kiceniuk, Jr., divided his time between elucidating aerodynamic principles and sharing an architectural concept for airport living in style. He has a long history in aviation, having designed the Icarus hang glider and Icarus V.  Icarus became one of the first electric aircraft in history, flying the length of the Flabob Airport runway in 1979 on energy from solar cells.  In roughly that time period, John Moody flew the airplane with wheels at Oshkosh, ushering in the new ultralight aircraft era.  Taras really started something.

To the Moon

After the evening barbecue, Al Bowers, recently retired Chief Scientist for the NASA Armstrong Flight Research Center gave a great overview of the Apollo Program, NASA’s three-person moonshots, six of which actually touched down on the moon.  The entire program cost about $25 billion ($167 billion in 2019 currency).  Even costlier, three astronauts lost their lives in a launch pad fire in 1967.

Al Bowers kept the late-evening crowd fascinated

Several “rehearsal” flights demonstrated different technologies and structures, and enabled engineers and scientists to overcome the many obstacles to success.  Al demonstrated one balancing problem for rockets sitting atop a column of fire by using a push broom atop his hand.  Your editor was good enough to remove it to get a better picture of Al addressing the crowd – only to be told it was a prop for the speech.

One of Al’s claims to fame is having the autographs of all the Apollo astronauts except for that of Gus Grissom, lost in that launch pad fire.  He shares the images of the signatures, lost in quiet admiration for all they represent.  They represent a heroism and national commitment that would be admired by all, in all ages.

NASA’s hand-drawn explanations for the moon missions delight Al Bowers

Your editor has been to nine of these events, and always comes home with an immense feeling of optimism and gratitude for the hard work these men and women do to further a cause for which they receive little credit. Keep the Experimental Soaring Association’s Western Workshop in mind for next year’s calendar.


Tehachapi Soars with New ideas

Every year, Labor Day weekend brings sailplane enthusiasts to Jeff Byard’s hangar on Mountain Valley Airport above Tehachapi, California.  It’s a friendly get-together that always has challenges and surprises for the participants.

History on the Field

This year, attendees were treated to an opening talk by Jeff Byard titled “Soaring, Something for Everybody.”  It lived up to its name, with a review of sailplanes of all types, with many examples right in the presentation hangar. For history buffs, jeff’s hangar, and Doug Fronius’ a few doors away, offer a glimpse of every type of hand-made soaring machine, including Doug’s recreation of Waldo Waterman’s 1911 hang glider, something which has been flown over the California coast.

Jeff’s collection includes a Slingsby SG-38 primary glider and T-21 side-by-side trainer (seen above in its native habitat, England).  The T-21 fuselage rests on the floor to the right as one opens the hangar doors, and the wings in mid-restoration hang nearby.  Jeff hopes to have this open-cockpit piece of history ready by next year to show how RAF pilots learned to fly gliders.

Four Concepts and a Favorite

Neal Pfeiffer followed with “Concept(s) for a Homebuilt Soaring Motorglider,” a look at how inspired home-builders might create a mid-performance touring motorglider – something one could take off and land on a small airport and use for trips from 200 up to 400 miles at speeds of 70 to 110 knots (80.5 to 126.6 mph) under power.  This would be a nice cross-country tourer under power, and if conditions permitted, one could switch off the engine and soar at 24:1 to 31:1 glide ratios.  Even though this is not contest-winning slipperiness, it would provide budget soaring expeditions for a couple without the cost of a towplane or the potential added costs and labor of an outlanding.

Neal Pfeiffer is restoring two ASK-14 motorgliders, powered by tiny Hirth four-cylinder, two-stroke engines

Neal showed four concepts, single and two-seat aircraft in sheet metal, composite, wood, and a final version in traditional steel-tube fuselage imaging a Wittman Tailwind with wood wings – somewhat like a modern form of a vintage sailplane or motorglider.  All concepts but the last could be seen on Mountain Valley’s field.

What Happened to the Toilet Seat?

Andrew Angellotti had a provocative title for his talk  – “Developing Flight Test Instrumentation Without the $30,000 Toilet Seat.”  As with many home-grown approaches to “big science,” Andrew’s instrumentation for developing highly-sensitive instrumentation (some of which flew on Perlan 2) involved some big items.  These included a load cell in a Styrofoam beer cooler, 3,062 pounds of water, a forklift, and a Dewar of liquid Nitrogen.  His web site shows the refined and lightweight instrumentation that enables accurate performance measurements without breaking the flight test budget

Here’s a video of Perlan on the ground and in flight, with a “beauty shot” of his probe at the 2:49 mark.

The skies over El Calafate in Argentina are filled with anticipation and hopefully soon, stratospheric mountain waves. While we wait for our first opportunities to soar again and attempt to reach our goal of 90,000 feet, #TBT to this season's launch video for #AirbusPerlanMission II.

Posted by The Perlan Project on Thursday, August 22, 2019

Low, Slow, and Cheap

Yours truly reported on his slow but ongoing efforts to build the world’s cheapest electric aircraft, which will be an ultralight Kimbrel Banty, an all-wood craft from 1984.  Mike Kimbrel sold his plans in 8-1/2” X 11” format for $25 a set, and by 1998 had sold 1,320 sets.  30 actual aircraft were flying by that time.

The big problem for your editor is keeping the aircraft inexpensive (“cheap”), forcing an investigation of brushed and brushless motors.  Brushed motors can be controlled with a simple potentiometer, while brushless motors require a more complex and expensive speed controller.  Batteries are still the most expensive part of the build and your editor is researching many possible ways to lower that cost.

Beauty, Speed and Strength

After lunch, participants enjoyed a double-header from Paulo Iscold with the construction of the Nixus sailplane – the first high-performance machine with total fly-by-wire control, and Eric Stewart showing how he followed strict discipline and ASTM protocols to perform, “Destructive Testing & Materials Characterization for an Experimental Race Plane.”

Nixus’ 92-foot wing droops on ground, flexes in flight

The pair has worked together on many projects and both managed to destroy big chunks of the sailplane and the race plane in their quest to build safe structures.  For Nixus, the 92-foot wings were extremely flexible, part of the reason “fly-by-wire” was almost a necessity – much like that on Fred To’s 1982 Phoenix, an inflatable, 100-foot span, pedal-powered craft.

100-foot span Phoenix in 1982, during test flights in London’s docklands. Inflatable plane used model airplane servos on rudders, elevons and could be controlled by pilot with transmitter or by remote pilot on ground

Paulo’s Nixus was tested in a most spectacular way.

Nixus wing spar being taken to its limit

Nixus wing spar just past its limit – pricey, but cheaper than having it happen in flight

Eric’s SR-1 racer’s tests, so far, are on smaller scale, using “coupons” of specifically-sized samples of sandwich construction (layers of carbon fiber on either side of a foam core) to determine structural limits.  He has built a light composites database from his research.

SR-1 will be small, light and fast – and strong

SR-1 will make record attempts in the FAI c-1a/0 class. Eric writes, “…Aircraft must weigh less than 661 lbs at takeoff, including pilot and fuel. With recent advancements in powerplants and lightweight components, our goal is to push the current record of 223mph to 275+mph. For regular updates, check us out at facebook.com/TheSR1Project.”

Examples of strips of different carbon weaves, cores tested for Eric Stewart’s SR-1

Where Will the Future Take Us?

Paul Gaines added another provocative title to the proceedings, “Understanding Another Stagnation Point- a Discussion About Aviation & the Next Generation.”  He opened a lively discussion of how to bring young people into the sport, a matter of concern among the many grey-haired audience members.  Although many ideas were floated, the subject remains an unanswered question.

(Stagnation point, in aeronautical terms, “Is  a point in a flow field where the local velocity of the fluid is zero,” according to Wikipedia.  A similar point occurs in human endeavors when all energy is lost in moving things forward.  Aviation has reached that point several times in the past, and we are the stewards of the heritage that should be maintained.  The future is our responsibility.)

That evening, following the potluck barbecue dinner, Dan Rihn and Doug Fronius staged a hilarious auction of things aeronautical and bizarre.  The good humor and fund-raising bids ended the day on a high note.

Tomorrow: Sunday’s Presentations and Al Bowers’ Master Class on Moon Shots


The Prieto Battery Receives Affirmation

Dr. Amy Prieto created her namesake battery a decade ago, and has been seeking funding and other support for its development ever since.  It gained such funding from Stanley Ventures in 2016.    Prieto Battery, as reported by GreenCarCongress.com then, is, “A company commercializing a 3D Lithium-ion battery technology (earlier post), announced a strategic investment from Stanley Ventures, the venture arm of Stanley Black & Decker, a world-leading provider of tools and storage, commercial electronic security and engineered fastening systems.”

Possibly more important that money, Dr. Prieto’s battery recently received third-party validation of its claimed safety and performance attributes from Energy Assurance, LLC.  GreenCarCongress reports, “Specifically, Prieto had a group of fully assembled batteries containing their proprietary 3D anode tested against an array of UL (Underwriters Laboratories) and IEC (International Electrotechnical Commission) standards for Li-ion chemistry. All of Prieto’s batteries had 100% success rate with zero failures.”

Dr. Prieto seems happy with these results, stating, “These results validate the science and manufacturing methodology we’ve been working on for a long time. Besides demonstrating that our chemistry and materials are safer, it’s equally as impressive that none of the cells failed and points to an exciting pivot point in our company, one where we move from focusing on R&D to getting our first product commercialized.”

Prieto’s manufacturing process is not-toxic, the only acid used is citric

Prieto claims advantages based on its porous copper foam-based structure.  Coated with “an ultra-thin polymer electrolyte and… surrounded by a cathode matrix,” the battery promises a power density comparable to super capacitors.

Its anode, coated with an electrodeposited copper antimonide (Cu2Sb) layer purportedly has an “unprecedented degree of stability,” excellent capacity and long-term cycling capability.  Prieto claims the materials allow low-cost manufacturing and scalable production.

The patent-pending Cu2Sb copper foam substrate awaits a patent, its structure ensuring continuous electrical contact throughout the 3D anode.  No costly annealing or other post treatment is required.  The material is conformal and very thin “to allow for the subsequent interpenetration into the structure by the cathode material. This layer is pin-hole free, which is critical for the overall performance of the battery. The strict demands on the electrolyte form the basis for additional intellectual property protection.”

Prieto claims its cells will be able to achieve power densities of 14,000 Watts per liter, while maintaining energy densities of 650 Watt-hours per liter.  Tesla’s 18650 (18 mm in diameter x 65 mm in length) batteries are calculated by Quora.com to manage 727 Wh/liter.  Its 2170 (21 mm x 70 mm) cells achieve 885 Wh/liter, and in pack form, 805 Wh/liter.  Power density for the Prieto battery is expected to reach 14,000 W/liter, considerably higher than more li-ion cells.

Whether the lower manufacturing costs will mean good sales for Prieto remains to be seen.  We are seeing the battery at the beginning of a development cycle, so future releases may fulfill the promise seen in the different manufacturing and configuration approach.  Prieto says it can make batteries tuned for energy or power and this flexibility may be its best selling point.


The I.D.E.A.L. Becomes Real with JabirWatt

Dr. David Ullman taught mechanical engineering and project management for over three decades, and his books on the mechanical design process are consistently sought after.  His current project, JabirWatt, is hangared at his home in Independence, Oregon, and combines the internal combustion propulsion of its Jabiru engine with the lift-enhancing addition of four electric ducted fan motors on the wings.  A project partner, Vince Homer, lives nearby on the airport.  Both have hangars filled with things of genius, including the well-instrumented wind tunnel on which David tests his ideas (or I.D.E.A.L – Integrated Distributed Electric-Augmented Lift).

David Ullman’s JabirWatt outside his Independence, Oregon hangar.  Four electric ducted fans (EDFs) blow air over the top the NACA 4414 airfoil

Slightly different from the approach promised in his presentation at last year’s Sustainable Aviation Symposium, the modified Jabiru sacrifices its rear seat for a large battery box to power the (now) four electric ducted fans (EDFs) atop the inner part of the wing.  He’s since presented at this year’s CAFE Foundation symposium and at AirVenture 2019.

Different From a Maxwell

Your editor has joked with David about his making a “poor man’s” X-57 Maxwell, after observing the similarities with that NASA research craft.  Others have seen the similaries, but David says the two planes differ “in man ways.”

  • NASA is using distributed electric propulsion they accelerate the air both above and below the wings with propellers thus not achieving the potential increase in lift that is possible with IDEAL
  • The Maxwell folds the propellers in cruising flight. This reduces drag in that part of the mission, but again, loses the lift advantage.
  • Nasa’s budget of $57M is slight larger than eSTOL-IDEAL’s budget (Less than $50k including the JabirWatt).

Martin Koxxy (left) and Bill Brigdon survey EDFs on wing of JabirWatt with giant slide rule and bent wing strut from broken airplane David rebuilt in background

Dave explains the four EDFs cannot power the airplane by themselves (that would take 24 such units), but their thrust over the top of the wing can lower the stall speed to around 30 mph. A stock Jabiru stalls at around 45 knots (52 mph).  Simulations show IDEAL stall speeds could be reduced to as low at 25 knots (28 mph) – far more survivable.  After all, impacts get worse at greater speeds.

He adds, “There is no known data on the relationship of stall speed to fatality rate. However, car fatality rates are instructive. At 52 mph, about 85% of car head-on accidents are fatal. At 28 mph this drops to 20% with 65% serious injury. Thus, if the analogy holds, IDEAL can potentially reduce the fatality rate significantly.”

Willard Custer in one of his early research craft

Some of David’s inspiration came from Willard Custer, father of the CusterWing, who said, “It’s the speed of the air, not the airspeed.”  Passing air through large channels wrapped around the propellers helped lift the aircraft and shortened takeoff and landing distances.

David points to a NASA research vehicle, the four-engine QSRA, shown here in a 1987 demonstration at Moffett Field.  Air blown over the top of the wing accounts for a great deal of the rather astonishing performance seen here.  One can understand why Cub Crafters is adding funds to David and Vince’s privately financed project.

We will have follow-ups on the airplane, including a breakdown of equipment and costs.   David is presenting at the upcoming Sustainable Aviation Symposium at the University of California at Berkeley.


Clean Hydrogen from Dirty Sources

Proton Technologies of Calgary, Canada has a startling approach to obtaining clean hydrogen – extraction from some of the dirtiest sources on earth.  Considering the company plans to pull hydrogen from fairly filthy tar sands, their Hygenic Earth Energy almost seems like a misnomer.

Tar sands oil extraction has been enormously controversial, with issues including arboreal forest destruction, native tribal displacement, and air and water pollution.

Proton hopes to ameliorate these problems in Alberta and elsewhere with adherence to this mission statement: “To rapidly transform energy systems worldwide—profitably and sustainably—might sound like a dream.  However it is entirely reasonable, perhaps inevitable, if you accept…

“Four Key Premises:

“1. Hydrogen is the foundation to a sustainable energy future

“2. The high cost and carbon emissions from hydrogen production are the only remaining obstacles

“3. Proton’s hygenic earth energy eliminates these obstacles

“4. The massive existing hydrogen market allows for rapid commercialization.”

Testing Their Premises

To develop their dream and test the real-world implications of their process, Proton acquired the Superb (the trade name) air injection test facility near Kerrobert, Saskatchewan.  The facility will enable Proton to “de-risk” technology development and improve timelines and cost efficiencies.

The site will enable Proton to steam heat residual carbon deposits (oil, natural gas) and extract only hydrogen while leaving fossil fuels in the ground.  Seeming a bit like fracking, the process is not intended to crack underground rocks, but to extract hydrogen.  Proton describes is thus: “By injecting oxygen into oil wells to combust the trapped hydrocarbons, Proton can generate enough heat in the process to produce hydrogen gas. This process leaves carbon sources trapped beneath the Earth’s surface in the form of carbon dioxide, carbon monoxide, methane, and other gases, while removing only hydrogen gas.

Proton’s Dr. Ian Gates, also of the Department of Chemical Engineering at the University of Calgary, explains, “There are vast oil sand reservoirs in several countries, with huge fields in Alberta in Canada, but also in Venezuela and other countries.”

Grant Strem, CEO of Proton Technologies says “This technique can draw up huge quantities of hydrogen while leaving the carbon in the ground. When working at production level, we anticipate we will be able to use the existing infrastructure and distribution chains to produce H2 for between 10 and 50 cents per kilo. This means it potentially costs a fraction of gasoline for equivalent output”. This compares with current H2 production costs of around $2/kilo. Around 5% of the H2 produced then powers the oxygen production plant, so the system more than pays for itself.”

With greater public availability and such low prices, companies such as ZeroAvia would be able to offer low-cost aerial taxis at previously unheard of rates while avoiding the 100LL smog that threatens private aviation’s future.

Hidden (So Far) Distribution

With only 50 (up from 31 three years ago) publicly-available hydrogen fueling stations in the US – mostly in California – and one in Canada, finding H2 for your fuel cell car or airplane may seem a dim prospect.  Commercial and municipal sources seem to abound, though, according to an Energy Department publication, State of the States: Fuel Cells in America 2016, 7th Edition Fuel Cell Technologies Office.

The current administration has not updated this report, which used to be updated on a more regular basis.

Extending the future of far-flung oil and gas fields without expanding their polluting influence on the atmosphere would certainly seem worth exploring.  A seemingly unlimited resource awaits, along with a cleaner future.


ZeroAvia Counts on Hydrogen

Tucked away in the quiet little airport at Hollister, California, ZeroAvia has stealthily been developing a hydrogen-powered Piper Malibu, and flying it for the last six months.  It sounds like a regular aircraft taking off and passing overhead, even with its two 130 kilowatt (174.26 horsepower) electric motors. ZeroAvia claims 275 kW (369 hp) for the pair.  From the videos, propeller noise seems to be much the same as a conventional, internal-combustion powered Malibu, but lacks the added noise of the engine.  Piper M-series aircraft are normally powered by a Teledyne Continental Motors TSIO-520BE engine rated at 310 hp (230 kW).

ZeroAvia’s 2-ton, 6-seat test platform is the largest zero-emissions aircraft flying, according to the company

Valery Miftakhov, ZeroAvia’s founder and CEO announced, “Right now we have an aircraft that’s six seats and 2 tons as an R&D demonstrator. Next year we’ll have a 20-seat aircraft and we’ll submit the design for [Federal Aviation Administration (FAA)] certification.  That’s what drives the 2022, 2023 timeline. At that point, we’re expecting to have certification and put the system into commercial service.”  The aircraft will have a range of 500 miles – commuter liner specs.

In response to your editor’s queries, Dr. Miftakhov (he has a PhD in physics) wrote that we will learn more about ZeroAvia’s partners (including motor suppliers) in the next few weeks.

Twin motors drive single propeller, provide redundancy for safety

An even bigger problem faces H2-powered aircraft, however, and ZeroAvia has a plan to counter it.

The Big Hangup – From Where Do We Get H2?

Dr.  Miftakhov explained, “…Providing a path to clean hydrogen is one of the key components of our vision. We are working with a number of fueling partners to set up a network of on-site hydrogen electrolysis facilities powered by on-site or near-site renewable electricity. In Southwestern USA, it would likely be solar, in Norway – hydro, in UK – wind, etc, etc.”

He has already worked with distributed electric power systems, founding and leading eMotorWerks, “a world leader in EV charging stations and grid-smart charging.”  Enel acquired the company in 2017.  Many of ZeroAvia’s team members were with eMotorWerks, with others bringing expertise from Tesla, BMW, gas producer Air Liquide and NVIDIA, a firm specializing in computer hardware, software, and artificial intelligence development.  Peter Fairley, writing in IEEE’s Spectrum, notes that this leadership gives credibility to the enterprise.

A Unique Business Plan

The Spectrum article explains the firm’s unique business plan.  “Rather than build airplanes, ZeroAvia plans to lease its powertrain and also supply hydrogen fuel to aircraft manufacturers or airlines. ‘We’re targeting power levels that are in use today and we are able to utilize the airframes that exist today, with minor modifications,’ says Miftakhov.”

Larger Hw-fueled craft might store hydrogen in pressurized tanks on wing-mounted pylons

With hydrogen weighing in at one pound for the equivalent energy of a gallon of gasoline (which weighs about six pounds), the potential weight savings is an obvious draw for the elemental fuel.  Storage containers can reduce some of that advantage, but modern carbon fiber or other composite materials can reduce that weight.

After sorting out development of the Malibu-sized craft, ZeroAvia plans on powering a larger craft in the commuter-liner size range.  Miftakhov’s schedule is a rapid one, and we can look forward to seeing his leased powerplants flying overhead in the next few years if all goes well.


Researchers at University of California at Berkeley announced a record in thermophotovoltaic efficiency, now at 29 percent, but with a few tweaks, soon to be at 50 percent.  This is great news for small drones, which could stay up for days, but possibly not a be-all, end-all for larger, more conventional electric aircraft.  Let’s examine the potential and the pitfalls involved.

Berkeley researchers think their breakthrough could result in “new photovoltaic engine”

The researchers’ “groundbreaking physical insight” and “novel design” applies thermophotovoltaic principles that are “an ultralight alternative power source.”  Eli Yablonovitch, professor of electrical engineering and computer science (EECS), wrote in a paper published in the Proceedings of the National Academy of Sciences, ““Thermophotovoltaics are compact and extremely efficient for a wide range of applications, from those that require as little as 100 watts, [such as] a lightweight unmanned aerial vehicle, to 100 megawatts, [providing] electricity for 36,000 homes. In comparison, a 100-megawatt combined cycle power plant is massive,”

Expanding on work he and his students published in 2011, Yablonovitch took a counter-intuitive approach to making more efficient solar cells.  Past efforts focused on increasing the number of photons that a cell absorbs. The paper notes, “Absorbed sunlight in a solar cell produces electrons that must be extracted from the cell as electricity. Those electrons that are not extracted fast enough, decay and release their energy. If that energy is released as heat, it reduces the solar cell’s power output. Miller’s calculations showed that if this released energy exits the cell as external fluorescence, it would boost the cell’s output voltage.”

It’s All Done with Mirrors

Berkeley reflective solar cell.  Graphite ribbon (glowing bar) heating the thermophotovoltaic cell sitting under it. (Photo by Luis M. Pazos Outόn, UC Berkeley)

“This is the central counter-intuitive result that permitted efficiency records to be broken,” Yablonovitch says.  In current efforts,   Heat generated by the absorption of photons lowers the efficiency of the solar cell – so Berkeley researchers exploit the heat rather than trying to get rid of it.

Mirror bounces heat to thermal emitter and recovers power

They place a “highly reflective” mirror within the cell and reflect low-energy infrared photons back to their source, extracting the otherwise wasted energy these photons possess.  It increases the voltage of the cell, but also generates heat at around 1,207° C (2204.6° F).  The current 29.1-percent efficiency can be raised to 50-percent, according to researchers.

It Won’t Fly Your Airplane – Yet

About 93 Watts of solar energy fall on each square foot of the earth’s surface, according to answers.com.  That’s if the sun is directly overhead and the sky is clear, of course.  Engineers use an average of 1,000 Watts per square meter for calculating solar panel sizes.  Let’s look at factors that lower that number.

Martin Koxxy (l) and Richard Steeves with Martin’s Quark e-Gull.  Both their e-Gulls are powered by Zero electric motorcycle motors

As an example, friends Richard Steeves in Madison, Wisconsin and Martin Koxxy built, own and fly Zero Motorcycle-powered e-Gulls designed by Mark Beierle.  They have investigated putting solar cells on the wings (both use the 28-foot version offered by Beierle).  Their aircraft have about 133 square feet of wing area.  120 square feet of 29.1-percent efficient solar cells would collect 11,160 Watts (11.16 kilowatts) and under the best possible conditions generate 3.25 kilowatts.  Your editor has seen Richard’s rough calculations for the e-Gull, showing the 28-foot span requires about 8.1 kilowatts to remain in level flight at its best lift:drag ratio.  (We’ll have an expanded and updated set of calculations soon.)

50-percent efficient solar cells promised by Berkeley would go a long way toward increasing range for these small machines, but would not keep them in sustained flight.  If the design’s liquid cooling can contain the high heat these cells generate, they would be very helpful in extending the range of aircraft, automobiles, and boats.  Smaller machines would seem to have an advantage at this point in the development cycle.