Eather One – When Friction is a Good Thing

Tribolectrics

Your editor has long promoted the idea of the Grand Unified Airplane, a vehicle which would essentially power itself from sunlight, piezoelectrics, structural batteries, and even the friction of the air over its surfaces.  He wrote about the concept in the May, 2013 Kitplanes, and has noted an increasing number of articles in scientific journals describing a variety of nanogenerators, including tribolectric types.

Your editor applied Grand Unified Airplane ideas to Richard Glassock’s concept for eight-seat powered sailplane.  (Wish someone would build it.)

Tribolectrics are not new, having been discovered in the 18th century and initially quantified by Johan Carl Wilcke, a Swedish Physicist in 1757.  “Tribo” comes from the Greek for “rub,” and as shown in the following video, even the rubbing of air over a surface can generate electricity.  Note that about the 1:25 point Dr. Wang blows across the nanogenerator and lights up the LEDs.

Taking that idea and running with it, Warsaw-based designer Michal Bonikowski designed the Eather One to run on electricity generated during the airplane’s movement through the air. As exotic as it looks, it’s not as wild-eyed as one might expect, coming as it does from a designer with 20 years experience and numerous awards to his credit.

Dark patches could be triboelectric nanogenerators on aircraft surface. Illustration: Michal Bonikowski

He was inspired partly by Airbus’ Maveric (Model Aircraft for Validation and Experimentation of Robust Innovative Controls) a blended wing body design. Powered by next-generation turbine engines, Maveric would achieve a 20-percent reduction in carbon emissions over current designs.  A 3.2-meter (10.5-feet) span first flew in France in 2019.

But, it’s still burning some form of fossil fuel, unless Airbus manages to economically convert enough McDonald’s French fry oil to aviation use soon.

After being lifted by electrically-powered engines, airplane would maintain forward motion based on friction with air.  Illustration: Michal Bonikowski

Bonikowski  writes about his dream machine.  “I enjoy all attempts to revolutionize flying. I have been thinking a lot about this lately, and what could happen if Airbus (Why not Boeing, or Embraer?) would like to create an electric plane. We all know that the main problem is the weight of a battery, but. The air is full of electricity, which can be recovered by the friction generated by the flying plane. In wings, during the flight, instead of fuel tanks, triboelectric nanogenerators can be installed, which, using the vibrations of the structure and friction generated by the bending of wings during the flight, can generate the energy needed to power several smaller electric motors. The energy efficiency of such systems is already large enough to be used in this kind of machine. In this case, the battery pack needed for carrying should only satisfy the need for takeoff and landing. The flight itself would be able to generate the energy needed to maintain it and most likely to charge the batteries.”

Electric motors, looking like ducted fans, would draw power from batteries, constantly recharged by triboelectric nanogenerators. Illustration: Michal Bonikowski

The elegance of pulling the energy for flight from the very air through which an aircraft passes seems like a wild dream, but coupled with increasingly power dense motors and energy dense batteries, this may not be a decades-out vision.  Could this concept be used with hydrogen fuel cells or advanced supercapacitors?  Certainly, the dream seems worth chasing.

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The Elektro-Weltrekordflug (electric world record flight) team had great success in its flight from Schänis, Switzerland to Norderney, on Germany’s North Sea.  Setting five of its intended seven world records and then flying back to Switzerland, the team and its Pipistrel Velis showed that electric flight can be a reality for light aircraft.  All we need are charging stations along the way.

Your Editor will do something not normal to the blog – repeat most of someone else’s writing with a few comments tossed in.

“The world record flight with the first certified electric aircraft from the Alps to the North Sea in Norderney was a success. The “Pipistrel Velis Electro” landed again in Schänis (Switzerland) on Sunday evening. In addition, five world records were set. The EWF team has ushered in a new era in aviation and has proven that electric flying is possible on long-haul routes.

The electric world record flight team (from left to right): Tom Albrecht,  Morell Westermann, Kerstin Zulechner, Stefan Pieper, Marco Buholzer, Malik Aziz, Tobi Pape

“For most of them, passenger flights with small battery-powered aircraft were a long way off. To prove that it is already a reality today, seven daring electric enthusiasts set off with the first certified electric light aircraft on August 31, 2020 and reached Norderney on September 2, 2020. In the process, five world records tumbled the combustion aircraft: your aircraft used less than a quarter of the energy for the route than conventional planes.

“This required challenging planning: there is no infrastructure for electric aircraft on the entire route. Therefore, two ground crews in electric cars had to drive two chargers in a rabbit and hedgehog game in front of the plane. The aircraft flies at about 120-150 km / h in a straight line, the cars have to adapt to the road conditions. Meticulous planning was necessary to minimize waiting times when loading.

Chargers were carried between landings by team members in cars

“The community of the podcast CleanElectric.de helped in a great way by testing the suitability of the three-phase current connections at airports throughout Germany in the run-up to the flight The mainstream press clearly shows this.  (Editor’s note: the public relations campaign the team managed was world-class itself.)

World Records

“The results documented by the Swiss ElectroSuisse for recognition as a world record with a certified electric aircraft will be submitted to the FAI (Fédération Aéronautique Internationale) in the coming days:

Lowest energy consumption (kWh / 100 km):

  • Overall, the flight consumed 190.951 kWh of electrical energy on the entire route (including losses from the charger, approx. 15%)
  • Total flown distance: 453 nm / 838.964 km
  • This means that the average consumption is 22.76 kWh / 100 km, which corresponds to 2.33 l diesel (energy equivalent diesel: 9.75 kWh / l)
  • (Editor’s note: Europeans had a so-called “three-liter car” ideal of consuming only three liters of fuel for every 100 kilometers in their econoboxes. The little Pipistrel managed to beat that ideal at a much better speed!)
  • Calculated over the entire distance, the Pipistrel Velis consumed the energy equivalent of 19.58 liters of diesel!
  • This puts the aircraft in the range of a Tesla Model S, making it a new benchmark in aviation. Comparable aircraft with internal combustion engines would consume about 4x to 5x more energy.

Typical view of countryside on trip

Highest average speed over 700 km (km / h)

  • Average speed on 838.956 km flown: 125.217 km / h (linear distance Schänis-Norderney: 738.37 km) (Editor’s note: that’s 77.63 mph, much better than speeds one can attain by car through twisty roads.)

Highest flight altitude ever reached with an electric aircraft (meter above main sea level) and fastest climb rate of 0-1000m / 1000-2000m / 2000-3000m (m / s)

  • The two planned records related to the reached flight altitude and the fastest climb rate were planned for Norderney, but could not be flown due to the weather on September 3rd, 2020. This means that the benchmark from the specification remains. (12,000 ft altitude)

Fastest average speed over 100km (km / h)

  • 136 km / h (84.32 nph) on the route from Lahr Airport to Karlsruhe / Baden-Baden Airport

Smallest number of intermediate stops over a distance of 700 km

  • Number of stops: 11 (without start and finish)

Longest electrically flown route in 24/48/56 hours (km)

Velis in flight with a mix of glass panels and steam gauges

  • 24 hours: 326.878 km on the first day (202.66 miles)
    (departure from Schänis airport on August 31, 2020 at 8:00 a.m., landing in Bad Dürkheim on August 31, 2020 at 6:00 p.m.)

The absolutely longest distance in 12 hours was flown on the way back from Mainz-Finthen airfield to Schänis airfield, a total of 382.44 km (237.11 miles) (departure Mainz-Finthen airfield on September 6th, 2020 at 8:19 am, landing Schänis airfield at 7:23 pm )

  • 48 h: 608.382 km on the first and second day (377.2 miles)
    (departure from Schänis airport on August 31, 2020 at 8:00 a.m., landing at Münster-Telgte on September 1, 2020 at 4:36 p.m.)
  • 56 h: 838.956 km, we covered the entire distance in this time!
    (Takeoff from Schänis Airfield on August 31, 2020 at 8:00 a.m., landing at Norderney Airfield on September 2, 2020 at 3:24 p.m.)

Great help from the community and airport operators
This project would not have been possible without the great support from the community of the “ CleanElectric ” podcast , operators and employees at the airfields and airports and the sponsors.
The community has swarmed across Germany to test sockets at airports with their electric cars, to organize welcome events, to inform the local media or to donate money.

Oerlinhasen Flugplatz provided a hearty greeting to the record seekers

Many airports have specially checked or even expanded their electrical installations. The reception and the organization on site were unique. The sponsors not only gave money, but are also consistently committed to the fields of power generation, charging infrastructure or other sustainability issues. Some of them met the team at airfields, traveled with them in person or were on site when they landed on Norderney.

Highlights and obstacles
No pioneering feat without the unexpected: Right at the start, the rainiest day in 15 years in Schänis, Switzerland, was waiting for the team. Therefore, the start had to be postponed by one day, as the runway was 30 cm under water and could only be pumped out overnight. After that, however, further planning went smoothly. There was a brief moment of shock at Baden-Baden Airport when the aircraft’s charger suddenly tested “positive” during the explosives check. Fortunately, this was resolved quickly – after a forklift truck had driven the device to a special X-ray machine. Finally, the fire brigade on Norderney received the electric aircraft with the rare and special honor of a water arc over the runway, then the happy team was welcomed by an enthusiastic crowd .

Broad media interest

The fact that the topic of sustainable mobility hits a nerve was proven not least by the great interest and reports from media such as Tagesthemen, WDR, NDR, SWR, SAT.1, RTL, dpa, Süddeutsche as well as countless local newspapers, blogs, YouTubers and podcasters .

Personal words from the team
“We would like to say thank you very much for your commitment and your time! This success is also your success. You all contributed to the fact that we were able to show a large public how efficient and everyday electric aviation can be! ”

Electric flying is still limited in range and so a lot of logistical effort had to be accepted for this long-haul flight. However, the aircraft was not originally intended for such a use: The Velis is a training aircraft for training pilots close to the airport, and it is ideally suited for this: practically inaudible, locally emission-free and cost-reduced.

Significance
The EWF team was convinced from the start that the flight would herald a new era in aviation – a milestone for aviation. Alex Vollmert, author of the comprehensive work “The golden book of aerospace” sees it that way. He traveled twice to stopovers on the flight so that he could immortalize the entire team in his life’s work – right behind aviation personalities like

  • the family of Otto Lilienthal
  • the grandson of the Wright brothers’ builder of the engine
  • the test pilot of the Concorde
  • 45 astronauts (including Buzz Aldrin and Eugene Cernan, the last person on the moon) and many others who have personally registered there.

The aircraft will be exhibited this weekend at the “Electrifly-In” symposium at Grenchen (CH) airfield (September 12/13, 2020).

All photos courtesy of shapes video production / Elektro-Weltrekordflug.

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It almost stops your editor in his tracks when he reflects that 93 years ago, Charles Lindbergh crossed the Atlantic in his Spirit of St. Louis.  Even more astounding, competitors may win the Freedom Flight Prize by the 100th anniversary of that flight by making a cross-Atlantic and return flight in a 100-passenger, all-electric airliner.

Carbon Footprint Ltd.

Lindbergh’s plane, custom built but derived from a Ryan M-1 mail plane, cost $10,580 ($158,357 in 2019 dollars) and earned the $25,000 Orteig Prize.  Now, an organization in England, “Carbon Footprint Ltd. has launched a competition to encourage sustainable passenger flight. It has created the Freedom Flight Prize, a competition focused on crossing the Atlantic Ocean 100-percent powered by renewable energy — with seating for 100. The first to do so will win the prize, which is expected to be worth millions of British pounds by the time there’s a winner,” according to Cleantechnica.com.

Will the FreedomFlight winner look like Will Doucet’s HERO ZeroEmissions Plane?

“The competition is open to manufacturers, research/academic groups and inventors to design and fly a 100+ seater passenger aircraft powered by 100-percent renewable energy. The plane must complete a return trip from London to New York; each leg of the trip in under 10 hours and must finish the return leg within 24 hours of starting out on the round trip.”

Not even Boeing’s dormant Zunum spinoff or the Electric Aircraft Group’s HERA plan on seating that many.  Jeff Engler’s Wright Electric plans on a 150-seat distributed electric propulsion machine.  Other potential contenders at this point seem to be more interested in creating smaller, lower-range craft.

The Rules

“Must be powered 100% by renewable energy (e.g. Electricity generated by solar, wind or hydro power; hydrogen made by electrolysis using renewable energy).​

Wright Electric could carry requisite passengers, but could it make the distance?

“Note: Aircraft using bio-fuels and synthetic aviation fuels are excluded from this Prize.

  1. “Must be able to carry at least 100 passengers.
  2. “Must be able to fly each leg in under 10 hours.
  3. “Must be non-stop – without the need to land to refuel between London and New York.
  4. “Must land back at London* within 24 hours of originally leaving for New York*.
  5. “The aircraft must meet the current safety standards in the US and UK and have complied with current approval processes for such a demonstration / test flight.
  6. “Participants must be registered with the Freedom Flight Prize before completing the historic flight.

“A representative of Carbon Footprint Ltd must be on-board the aircraft to validate the legitimacy of the flight.

​“The first person, company or team to do this will be awarded the Freedom Flight Prize Fund and take their rightful place in aviation history.”

The Small Print…

Boeing offshoot Zunum was not planned to be over 50 passengers

“Carbon Footprint Ltd holds the right to update the rules from time to time. This may include clarifications and corrections, but will never change the ultimate goal of the Freedom Flight Prize which is enabling zero carbon aviation.

​“*Airports must be within a 50 mile radius of these cities. The route can also be the other way round i.e. New York to London to New York.”

Details for how to enter the competition can be found here.

 3,462.42 miles

The shortest air distance between London and New York is 3,462.42 miles, the great circle route distance Charles Lindbergh achieved in his 1927 flight.  That means the aircraft can cruise at around 350 miles per hour (perhaps a little more to make up for altitude gain and approach descent), enough to complete the trip in the 10-hour limit.  This is 63-percent of the average 550 mph of current jetliners.

These are important points.  Doubling the speed of an airplane increases the drag by the square, meaning an equivalent airplane traveling twice the speed of another will generate four times the drag.  Even worse, from what your editor understands, Power required for that doubled speed goes up by the cube factor.  The faster airplane will require eight times the power.

Pipistrel HY4 is a hydrogen-powered derivation of Green Flight Challenge winner – but only four seats and regional range

This probably helped set the rules for the 2011 Green Flight Challenge, batteries being what they were back then.  The 200 mile route and 100 mph cruising speeds led to extraordinary passenger miles for energy equivalent to that of gasoline.  Interestingly, the four craft that took part in that competition are still flying and achieving new levels of economy and performance.

Who’s Behind This?

Carbon Footprint Ltd. is an international operation that seems to be on every continent except Antarctica, promoting carbon reduction projects from clean stoves for developing nations to reducing deforestation and implementing clean energy projects.  They seem well connected and fully capable of managing this project to fruition.

John Buckley, Managing Director of Carbon Footprint Ltd, is an aerospace engineer, and founder of the Freedom Flight Prize.  He explained, “This is the revolution that I have been waiting my whole career for – the Freedom Flight Prize puts 100% renewable flights right in the spotlight in order to address the climate emergency we face. The Prize does not accept the compromise that long haul travel produces a high carbon footprint – in fact it recognizes that the technologies to power flights solely on sustainable renewable energy are available. We anticipate that the Freedom Flight Prize will propel the travel industry to deliver on the needs of the people and the planet.”

This might be an answer to the spate of “flight shaming” that held sway before the pandemic made such concerns moot.  If airlines can “clean up their act” in a significant way, many objections to their CO2 emissions and contrails may literally go away.

Just as the Orteig Prize drove Lindbergh to talk a small aircraft company in San Diego into building his Spirit, and the Green Flight Challenge inspired Tine’ Tomazic at Pipistrel to come up with the winning G4, today’s Freedom Flight Prize may cause the best designers and builders to come forth with something just as revolutionary as those past prize winners.  Luck to all.

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Today’s Entry comes from Great Britain, courtesy of Jenna Bose, a young writer eager to explore the burgeoning world of electric aviation.  Your editor thinks you will find her outlook refreshing, open-minded and mind-opening.   We look forward to more of her contributions.

Electric Aviation Group’s HERA, an electric airliner for the future.                  Image Credit: pikist.com

Sustainability has been the driving factor behind most technological innovations, and aviation is no exception. A new report by the Environmental and Energy Study Institute (EESI) states that aircraft alone contribute at least 12 percent of the U. S. transportation emissions, which is currently at 1,091 million metric tons. Globally, the numbers aren’t too inspiring, either. After all, the same EESI report informs that aviation was responsible for 2.4 percent of total carbon dioxide on the planet two years ago. Numbers are still being computed for 2019, but they don’t look promising.

The Solution? Electric Aircraft

Fortunately, manufacturers around the world have made great strides to make aviation greener with reverberating success. Just this July, an electric aviation group in the UK went big by topping last year’s design with an even better machine: the Hybrid Electric Regional Aircraft (HERA). Other countries like France and Slovenia are also making huge strides in electric aviation.

Zunum Aero’s regional electric airliners may be held up by Boeing’s financial difficulties

As one of the leading aircraft manufacturers in the world, the US has produced promising machines, too. The Zunum Aero from 2017, the Bye Aerospace eFlyers from 2018, and last year’s Ampaire are some of the country’s top designs. But they were all funded by private companies and donors.

However, local efforts for electric aviation could speed up as the federal government has expressed interest in pushing this innovation through. Last month, the Department of Energy announced that it would be releasing $33 million to fund 17 different electric aviation projects. This move was made as part of their Advanced Research Projects Agency-Energy’s Aviation-class Synergistically Cooled Electric-motors with iNtegrated Drives (ASCEND) and Range Extenders for Electric Aviation with Low Carbon and High Efficiency (REEACH) programs.

ASCEND and REEACH

ASCEND’s goal is to create lightweight all-electric powertrains with advanced thermal management systems to

enable net-zero carbon emissions for single-aisle passenger commercial aircraft. Meanwhile, REEACH’s aim is to come up with cost-effective ways to power sub-systems for electric aircraft, without losing anything on the performance aspect. The $33 million will be split into $14.5 million for ASCEND (nine projects) and $18.5 million for REEACH (eight projects), respectively.

Some of the projects associated with both include Texas A&M’s Multi-Physical Co-Design of Next Generation Axial Motors for Aerospace Applications and Hyper Tech’s Cryo Thermal Management of High-Power Density Motors and Drives. Electric aviation leaders like General Electric and Wright Electric are also receiving funds.

The Future of Electric Aviation

But it’s not just projects involved with ASCEND and REEACH that are seeing advancements this year. In 2018, Tesla and SpaceX announced that they were planning to develop an electric vertical take-off and landing aircraft, but never followed through on the announcement. The design for the aircraft involved a sophisticated power delivery system design, with billions of transistors demanding an incredible power supply that Tesla was not equipped to develop.

Speculative, but coming from Elon Musk, possible. The Model V is a one-passenger electric eVTOL (electric Vertical Takeoff and Landing) vehicle

However, a few days ago, Elon Musk announced that he saw that batteries enabling his design could come to market within “three to four years” and that he was putting the project back in action.

Air taxis may also become commonplace, as research is abundantly being pooled into this field as well. During last January’s Consumer Electronics Show, Uber and Hyundai Motor revealed a concept electric aircraft that’s able to fly on trips of up to 60 miles, with speeds at 180 miles/hour. Boeing proclaimed last year that they were working with Porsche to create an urban electric flying vehicle as well.

Overall, electric aviation is seeing more activity now than ever. Indeed, between national interest and advancements in technology, the future could be arriving no less than a decade later.

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On to the North Sea, Electrically

Elektroweltrekordflug

A team in Switzerland attempted an elektroweltrekordflug, an electric world record flight, hoping to set seven world records in one 700-kilometer trip. Flying a new, certified Pipistrel Velis, the team of Marco Buholzer and co-pilot Morell Westermann hoped to find their way into the Guinness Book of World Records for the following:

• Lowest energy consumption (kWh / 100 km -62 miles) over 700km (434 miles)
• Highest average speed over 700 km (km / h)
• Highest flight altitude ever reached with an electric aircraft (meters – 3.280 feet – above main sea level)
• Fastest climbing performance from 0-1000m / 1000-2000m / 2000-3000m (m / s)
• Fastest average speed over 100km (km / h)
• Smallest number of intermediate stops over a distance of 700 km (number of stops)`
• Longest electrically flown route in 24/48/56 hours (km)

The team made much the same point that Gabriel DeVault made in accepting the MacCready Prize at last year’s Sustainable Aviation Symposium. “Anyone who drives an e-car knows that the route Zurich-Norderney is no longer a problem with an electric car. With the electric airplane, however, it is a modern adventure, a flying expedition from the Alps to the North Sea.”

Pipistrel Velis braves a wet Monday morning to head north

Following a one-day weather delay, the trek went fairly uneventfully. On Sunday morning, August 30, over 100 people and 50 electric cars crowded the airfield at Schänis (LSZX), with a pop-up e-mobility show and a Futuricum e-truck on display. Planned to start around 10:00, the world record flight was primed to head for Donaueschingen (EDTD), where it was scheduled to land around 2:30 local time. Weather, unfortunately, was damp and dismal, but didn’t dampen the crowd’s enthusiasm. The party went on, but the flight didn’t – until the following morning, when the little Velis hopped into the air and made its way north.

First Landing in Germany

After a recharging stop in Birrfeld on Switzerland’s northern border, the pair of pilots navigated to Donaueschingen airfield. Hans-Jürgen Götz reported from the flight’s first stop in Germany that, “Anyone who thought airplanes were loud and only burn fossil fuels was taught a different story on Monday. Shortly after eleven o’clock the first civilly registered electric airplane landed… almost silent and purely electric.”Buholzer and Morell were met by “around 50 electric vehicle enthusiasts from the region.”

Marco Buholzer and Morell Westermann from Schänis stop to charge their electric airplane Pipistrel Velis Elektro at Donaueschingen airfield. | Image: Hans-Jürgen Götz

At Bad Dürkheim (EDRF) the team was promised “serious” hospitality and “a great audience program.” They were not disappointed. Food and beverages and dozens of electric cars and their owners were on hand. The team held forth with a mini lecture about the trip up to that point and the project.

That busy afternoon saw stops at Lahr airfield (B140), Karlsruhe / Baden-Baden Airport (FKB), and a well-deserved overnight stay at the Flugplatz Bad Dürkheim.

Tuesday to Munster-Telge

An early departure from Bad Dürkheim took the team to the Mainz-Finthen Airfield. After recharging with the gear the support crew carried in their automobiles, the airplane departed for Siegerland Airport in Burbach. Three hours later, the Pipistrel and the small convoy of support cars left for Meschede-Schüren Airfield, on the well-named Otto-Lilienthal-Strasse. A final arrival at the Flugplatz Münster-Telgte was followed by a community celebration.

Wednesday to the North Sea

Another early departure took the pilots to the civil part of the Diepholz Air Base – ETND. A short stop there enabled a takeoff for Westerstede-Felde Airfield, a lovely field in the midst of sylvan greenery.

A last short hop ended the trek at Norderney Airfield, where they were greeted by the local fire department and a welcoming committee that included the local mayor.

A proper welcome for a new sight at this airport – an electric record setter (we hope)

Electric Cars and Chargers

Much like Gabriel DeVault’s flight around central California, the crew included a team that drove ahead with chargers and a special pair of data recorders for the record declaration. They describe their coordination. “As soon as we got out, the charging cable was immediately plugged in. After all, it should move on quickly. Since there is no charging infrastructure for electric aircraft at any airfield, a team with the electric car and a charger will each drive ahead to the nearest landing site.”

The Team takes a bow at journey’s end

The Return Trip

The flight back to Schanis simply reversed the stops going home. After all, the team was available to charge things, and there was even a Green Motion charging station at Birrfeld’s Flugplatz.  We don’t know if Guinness has validated the seven records for which the flight was destined, and we will be reporting that outcome as it becomes known. Congratulations to all who made this historic flight possible.

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Like the TV commercial of the obviously wealthy couple requesting an architect design a kitchen around their choice of designer faucet, Pipistrel may have designed a cargo aircraft around the ubiquitous EUR-pallet.  Its extraordinary Nuuva V300 can hold three of these 1,200 mm × 800 mm × 144 mm (47.2 in × 31.5 in × 5.7 in) platforms laden with items destined for distant places.  The common dimensions enable planning a load (also considering total weight) that can be inserted into the Nuuva with a standard forklift.  The cargo hold can manage up to 460 kilograms (1,000 pounds) within three cubic meters (106 cubic feet) of space, a little more than an Escalade.

Cargo hold of Nuuva V300 can hold three E-Pals, as they are called

Electricity to Lift, Gasoline to Push

It takes a big vehicle with loads of power to hoist this kind of cargo.  Pipistrel sticks with proven systems for vertical and horizontal flight.  “The Nuuva V300 takes-off and lands using eight independent battery-powered Pipistrel E-811 electric motors, already Type Certified. This revolutionary zero-emission powertrain is entirely liquid-cooled, including the batteries, and has demonstrated the ability to withstand faults, battery thermal runaway events, and crash loads as part of the EASA certification process.  Using eight of the same motors as a Velis, which this last weekend demonstrated its capabilities on a 700-kilometer record attempt, counts as a confidence builder.

Pipistrel reports, “Nuuva V300’s batteries can be charged by simply plugging-in to a SkyChargeTM by Pipistrel and Green Motion charging station.”

Pushing it along is a certified four-stroke fossil-fuel powered engine, quite possibly a Rotax that seems to power much of European aviation.  Fuel consumption of 30 liters (eight gallons) per hour can use a “typical” fuel load of 65 kilograms (143 pounds) to move a load for just under three hours. At a “fast cruise speed” of 220 kilometers per hour (119 knots or 137 mph) that would give a no-reserve range of about 625 kilometers (387 miles) – rounding down for safety’s sake.  A more reasonable economy cruise would allow 165 km/hr or 89 knots (102 mph).  That would still allow 480 miles range or just under 300 miles.  (Note: these calculations are very “loose” and subject to scrutiny.)

Nuuva V300s will be able to land and take off at 2,500 meters (8,200 feet) above sea level helped by the craft’s 13.2 meter (43 feet, 4 inch) wingspan.  They will be able to cruise at 6,000 meters or 19,700 feet ASL.  Of course, all this will depend on total weight, which can top out at 1,700 kg or  3,750 pounds.

Unpiloted operation will enable hazardous missions without danger to humans

Pipistrel claims an operating cost “10 times lower” than helicopters, which should make these vehicles advantageous for non-profit organizations needing access to remote locations. An illustration shows a Nuuva over stormy seas heading away from an oil platform – reducing hazards for human crews.  As with eHang and Lilium, this fully autonomous flight will be remotely surveyed from the ground, and experience will probably determine the relative proportions of human/machine control.

Not an 801

Pipistrel hastens to note that the Nuuva is not an eVTOL 801, the passenger-carrying Uber-centric Urban Air Mobility machine.  The Nuuva comes from a clean sheet and different design parameters.

Despite having lifting and tractor propellers the Nuuva V300 and 801 are totally different

A Smaller Cousin

A Nuuva V20 will accommodate up to a 20 kilogram (44 pound) package and haul it up to 1,000 kilometers (620 miles) with auxiliary fuel tanks.  Like the V300, it has eight lifting propellers and one internal-combustion-engine-powered propeller.  It can carry its load at a fast 100 kilometers per hour (54 knots or 62 mph), or a more leisurely 75 km/hr (41 knots or 47 mph).

Shown on a tarmac, the V300 and V20 display their relative sizes

One wonders what Pipistrel has coming next.  Will there be intermediate capacity Nuuvas, hybrid Velis’s, or some other even more advanced technology on its way?

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Amazon PrimeAir FAA Approved

St. Paul gave us the idea that there are several heavens, a layered set of spiritual levels increasingly sublime with altitude.  That’s why there’s a “seventh heaven” of love, tranquility and bliss.  Then there are earthly regulations to consider.

The FAA’s approval meets with Amazon’s approval.  “We’re excited about Prime Air — a future delivery system from Amazon designed to safely get packages to customers in 30 minutes or less using unmanned aerial vehicles, also called drones. Prime Air has great potential to enhance the services we already provide to millions of customers by providing rapid parcel delivery that will also increase the overall safety and efficiency of the transportation system.”

Such services will be limited to the range available with drones.

Jeff Wilke introduces Amazon drone at re:MARS

One such unit, introduced by Jeff Wilke (Chief of Consumer Business) at Amazon’s  re:MARS Conference (Machine Learning, Automation, Robotics and Space) last year, seems large enough to pick up more than the five pounds listed in Amazon’s goals.  Wilke describes its abilities in an Amazon blog entry.

The drone’s design includes shrouded propellers, necessary to protect small children and animals at the drop zone, and perhaps grabby adults anxious for their new sneakers.

A video of Amazon’s first delivery using a different aerial vehicle shows an idyllic country setting and a clearing large enough to ensure safe drop-offs.

How this might work for suburban housewives and their broods requires some preparation by the home’s occupants.  Wilke’s blog entry explains the necessities.  “For the drone to descend for delivery, we need a small area around the delivery location that is clear of people, animals, or obstacles. We determine this using explainable stereo vision in parallel with sophisticated AI algorithms trained to detect people and animals from above.”

In Jeremy Clarkson’s depiction, one might want to lock that dog in the garage until the drone has departed.  In the meantime, artificial intelligence algorithms will help detect power, telephone and clothes lines as the drone makes its descent on the pre-marked landing zone.

Amazon is trumpeting its intention to make the company emission free within the next decade, and to achieve “Shipment Zero, the company’s vision to make all Amazon shipments net zero carbon, with 50% of all shipments net zero by 2030.”  This aspect of the program would certainly be welcome.

This could be a truly disruptive technology, with social and economic consequences might be felt by having fewer driver jobs for human intelligence platforms.  Ultimately we might see massive unemployment and limited need or opportunity to leave our dwellings. What will happen when the sky is dark with drones and we have no meaningful ways of making our homes our own private fulfillment centers?

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DOE Promotes Carbon Neutrality Aeronautically

Both GreenCarCongress.com and CleanTechnica share information about the Department of Energy’s funding of 17 projects in two Advanced Research Projects Agency – Energy (ARPA-E) categories.  Prepare for the inevitable rush of acronyms.  All the projects seem to be reserved for applications on single-aisle short- and intermediate-range airliners, with emphasis on economy of operation, carbon neutrality and lowest possible emissions.

ASCEND

Powertrain related, ASCEND (Aviation-class Synergistically Cooled Electric-motors with iNtegrated Drives) will fund nine projects with $14.5 in Phase 1 money.  Funds will help recipients, “Work to develop innovative, lightweight, and ultra-efficient all-electric powertrain with advanced thermal management systems that help enable efficient net-zero carbon emissions for single-aisle passenger commercial aircraft.”

  • Raytheon Technologies Research Center has three projects in two ARPA-E categories, including their own Ultra-Light, inTegrated, Reliable, Aviation-class, Co-Optimized Motor & Power converter with Advanced Cooling Technology (ULTRA-COMPACT) for which they received $2,330,13.  Their system will incorporate advanced materials and techniques in permanent magnets, drive topology, thermal management, and composite gearboxes.
  • Marquette University has been given $1.600,000 to develop a next-generation High Power Density Motor Equipped with Additively Manufactured Windings Integrated with Advanced Cooling and Modular Integrated Power Electronics.
  • General Electric Global Research adds its own acronym. $2,300,000 goes to an Electric Flightworthy Lightweight Integrated Thermally-Enhanced powertrain System (eFLITES) for Narrow-body Commercial Aircraft.  Their 2 megawatt, fully integrated all-electric aircraft powertrain will, GE claims, “Lead to significant mass reduction and thus increase in specific power density while maintaining a very high electrical-to-mechanical energy conversion efficiency.”
  • Honeywell’s Advanced Electric Propulsion System (AEPS) will receive $1,800,000.  Their “novel high-voltage 500 kW advanced electric propulsion system (AEPS) with a high efficiency and a high-power density,” and be cost effective. One feature to look for will be the intrinsic cooling system.
  • University of California, Santa Cruz is developing a Flux-Switching Machine Based All-Electric Power Train for Future Aircraft, for which they are granted $854,495. Their flux-switching motor and superconducting field coils sound advanced, and their cryogenic cooling follows suit.
  • Texas A&M Engineering Experiment Station fields a Multi-Physical Co-Design of Next Generation Axial Motors for Aerospace Application, worth $1,300,000 in ARPA-E funds.  Their carbon fiber axial-flux motor, GaN multilevel inverter, nanocomposite electrical insulation, and “two phase thermal management system with zeolite thermal energy storage” will allow high power and subdue high temperatures.
  • Hyper Tech Research Inc.will receive $2,910,479 to design and demonstrate Cryo Thermal Management of High Power Density Motors and Drives.   “If successful, the system will allow for a cost-effective motor capable of operating at a higher current density compared with existing conventional non-cryogenic motors without using superconductors.”

  • Wright Electric receives $647,039 for its Second Generation Motor for Large Electric Aircraft Propulsion Systems. “The team plans to use an aggressive cooling strategy coupled with a high frequency inverter.”  Phase one will see the detailed design and subcomponent testing, with phase two leading to the actual construction and testing of the system.
  • Advanced Magnet Lab, Inc.has  $655,354 to develop its High Power Density Dual Rotor Permanent Magnet Motor with Integrated Cooling and Drive for Aircraft Propulsion.  AML seeks to develop motors with an integrated SiC drive with an “overall specific power beyond 12 kW/kg.

REEACH

Eight projects will split $18.5 million in funding to develop Range Extenders for Electric Aviation with Low Carbon and High Efficiency (REEACH).

  • Raytheon Technologies Research Center focuses on a unique supercritical carbon dioxide (sCO2) working fluid in their Compact Propulsion Engine Optimized with Waste Heat Recovery (CO-POWER). This earns them a $2,815,760 grant.  Their sCO2 power generation and waste recovery systems are claimed to enable, “Up to a 20% fuel burn savings. The system can operate with any carbon neutral liquid fuel to achieve net-zero GHG emissions.”
  • Raytheon Technologies Research Center gains$2,652,778 to create a Zero-carbon Ammonia-Powered Turboelectric (ZAPTurbo) Propulsion System. This system, “Uses green ammonia as both a fuel and a coolant via regenerative cooling. Coke-free heating of this carbon-free ammonia fuel enables a high level of waste-heat recovery that will be used for the endothermic cracking of ammonia prior to its combustion, significantly increasing the cycle efficiency.”  The system includes battery boost for takeoffs and climbs.  Perhaps most surprising, in cruising flight, the system would have a 66-percent energy conversion efficiency.
  • General Electric Company, GE Research will use its $2,529,340 to develop its FueL CelL Embedded ENgine (FLyCLEEN).  FLyCLEEN uses “solid oxide fuel cells… integrated with the combustion chamber of a gas turbine engine-generator, yielding a hybrid system operating on synfuel with performance that maximizes the power density and energy efficiency of each component.”

  • University of Maryland receives $2,798,489 for its Hybrid SOFC-Turbogenerator for Aircraft.  (What? No acronym?)  A solid oxide fuel cell (SOFC) in the flow path of a gas turbine that also drives an electrical generator and recovers waste heat and unused fuel from the fuel cell.  The system operates on carbon-neutral, liquefied bio-methane.
  • University of Louisiana at Lafayette’s High Performance Metal-Supported SOFC System for Range Extension of Commercial Aviation garners $2,263,000.  This energy storage and power generation (ESPG) system for aircraft propulsion will consist of metal-supported solid oxide fuel cells (MS-SOFCs) and turbogenerators using carbon-neutral synfuel.  The team promises “innovative” manufacturing techniques.
  • University of California, San Diego earns $2,131,246 for its High-Efficiency and Low-Carbon Energy Storage and Power Generation System for Electric Aviation.  The school,  “Aims to develop a high-efficiency and low-carbon energy storage and power generation (ESPG) system operating on bio-LNG for electric aviation.”  Their stacked SOFCs will be arrayed in electrical and gas flow parallel and series connections.  They claim their system will employ “exceptional high power density direct methane cells made by sputtering thin-film deposition process.”
  • Fuceltech Inc.’s  Extremely Lightweight Fuel Cell Based Power Supply System for Commercial Aircraft, which earns them a $1,656,438 grant employs a “monopolar wound fuel cell potentially as high as 10kW rating and a novel stacking approach to deliver hundreds of kWs of power from a single small and lightweight stack.”  The system will be fueled by ethanol.
  • Precision Combustion, Inc. intends to provide SOFCs for FLIGHT in return for its $1,750,590.  The system includes an “exceptionally power-dense solid oxide fuel cell” powered by “energy-dense carbon neutral liquid fuels.”  “Hybridized system architecture” should provide “ultra-high” system efficiency.

ARPA-E Director Lane Genatowski explains, “Millions of Americans travel on single-aisle aircraft every year, contributing to continued increases in energy use and emissions by commercial airlines.  REEACH and ASCEND teams will work to lower these burdens by creating innovative new systems to enable more cost-effective and efficient flight systems for commercial travel.”

REEACH and ASCEND teams will attempt to reduce passenger-distance-specific CO2 emissions for commercial single-aisle aircraft from “nearly double that of any other individual widely used transportation source, including by rail, bus, or car.”  All of the systems hope to reach that aim through the use of carbon neutral liquid fuels.

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SolarStratos Announces First Solar Free Fall

If you happen to be in Payerne, Switzerland tomorrow morning around 7:00 a. m. Tuesday morning, August 25, you might want to visit the local airport.  There, the SolarStratos team will stage a demonstration flight with a free fall parachute jump by the project’s founder.

Miquel Iturmendi will pilot Raphael Domjan to an unspecified height, from which Domjan will depart the aircraft and free fall, open his parachute, and join the gathered throng.  Iturmendi will presumably return the airplane shortly thereafter.

We hope SolarStratos will allow viewers to play along with the cockpit virtuel

We’re not sure whether this flight will be available for Cockpit Virtuel viewing, but future expeditions should have that feature, much like the Perlan Project’s world altitude record ventures.   Iturmendi was co-pilot on one run to 65,000 feet.

This video, just a few days old, shows the airplane ready for its dual-occupant flight.  In true cinema verite’ style, it forgoes narration and soundtrack music, allowing us to hear the ambient sounds of SolarStratos.

A retrospective of past trials and triumphs for the program, this video includes the dramatic breaking of the wing in a stress test.  Calin Gologan,  a master of lightweight structures, designed a replacement that is ready for whatever comes.  Although only available in French, the message about climate change near the end is unmistakable.

Short Notice

The announcement hit your editor’s inbox just this morning, and the events take place tomorrow morning, Payerne time, or 1:00 am eastern daylight time and 11:00 am Pacific daylight time.

LIVE TV will be available on the SolarStatos website, as well as at: https://livestream.com/swisslivehd/solarstratos

Flight details will be posted on the project’s Facebook account: https://www.facebook.com/SolarStratos/

On Thursday, August 20, Iturmendi took project founder Domjan for his first solar flight, making it only the second time a sun-powered airplane has carried two people aloft.  Eric and Irena Raymond were first with their Sunseeker Duo several years ago.

Miguel Iturmendi (front seat) takes Raphael Domjan for his first solar-powered flight

After the 48-minute flight Domjan reflected, “What a long way I have come since I dreamed of flying with solar energy during my Pacific crossing aboard my solar boat PlanetSolar, it’s incredible! Thank you to all my team, our partners and all the people who have supported us for all these years.”

SolarStratos explains the grander goals of the project. “Beyond these technological and human feats, SolarStratos’ priority objective is to promote solar energy in order to protect the climate of our planet from greenhouse gases, by demonstrating that concepts and projects that seemed inconceivable a few years ago are now possible thanks to the technologies available today.”

As they become available, this blog will include the videos and photos of tomorrow’s event.

And It Really Happened!

True to plan and seemingly without impediment, Domjan and Iturmendi made a leisurely climb of about one meter per second (about 197 feet per minute) up to the jumpoff point of 1,520 meters (5,000 feet).  Their press release this morning tells it all.

Payerne, 25 August 2020 – Raphaël Domjan and the SolarStratos team achieved two world firsts this morning in Payerne.

“Exclusively powered by solar energy, the experimental aircraft took off from the Broyard airfield at 7.40 am, with test pilot Miguel A. Iturmendi and Raphaël Domjan, initiator and future pilot of SolarStratos.

‘After a short climb and after reaching an altitude of 5000 feet (1520 metres), Raphaël Domjan threw himself into the void, freefalling several hundred metres and reaching a speed of more than 150 km/h before landing in front of the team base and an array of guests.

‘Two world firsts were achieved during this historic flight: Raphaël Domjan made the first jump in history from an electric plane and also accomplished the first solar free fall, without any CO2 emissions.

Free as a bird, Raphael Domjan departs a perfectly good solar-powered airplane

“I am very proud of this achievement”, said the Neuchâtel explorer and lecturer. “Our aim is to demonstrate the potential of solar energy and electric mobility. It is a message of hope for future generations: tomorrow they will still be able to dream and carry out activities such as parachuting, for example, but without greenhouse gas emissions and in absolute silence. I have always been fascinated by aeroplanes and I hope that this will continue to make the young people of tomorrow dream, thanks to aircraft that are more respectful of our planet and our climate.”

“Very impressed by the recent progress of SolarStratos, and sensitive to the image conveyed by the SolarStratos project, Nicolas Bideau, Director of Presence Suisse, said he was very moved. “One of my roles is to find ambassadors for Switzerland, who convey a positive image of our country. Historically, Switzerland was built by pioneers who took risks. This project reflects the power of dreams, turned into a concrete project for our country.”

“Passionate about the SolarStratos adventure, Bertrand Piccard is “always happy to see people realize their dreams.  What Raphaël does is fantastic’, he says. ‘His project illustrates the new cycle that now characterizes aviation, which must imperatively adapt to renewable energies.'”

“Representing the International Aeronautical Federation, Alphons Hubman, states that he is ‘always on the lookout for new technologies. The SolarStratos project illustrates this new trend with a pioneering spirit. What they have achieved is extraordinary”.

“The world premieres of the SolarStratos team were broadcast live on live TV, and can be viewed on the website www.solarstratos.com.”

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Oxis Batteries to Fly in Two Airplanes

While we wait yet another five years for commercial development of each newly announced but promising battery chemistry, one company has its cells ready to fly in Bye Aerospace’s eFlyer 2 and in Texas Aircraft’s Colt S-LSA.  Oxis Energy has managed to leapfrog lithium-ion makers with its lithium-sulfur battery packs packing 400 Watt-hours per kilogram.  Considering the best announced pack-level li-ion performance has been 260 W-hr/kg, the leap is significant.

Batteries, for now, are at the heart of electric aircraft.  Until Doc Brown’s Flux Capacitor or a hydrogen fuel cell with Dollar Tree refills comes along, batteries are battling it out for our airborne dollars.  Lithium-ion remains in the forefront, with Tesla staging its shareholders’ meeting and its long-anticipated “Battery Day” on September 22.  Elon Musk has been dangling the promise of a million-mile battery for the last year, which may tie in with Chinese manufacturer Contemporary Amperex Technology (CATL).   According to Bloomberg, CATL’s, “Chairman and founder Zeng Yuqun said the company is ready with a battery pack that’ll last 1.2 million miles before needing to be replaced.”  Ostensibly, Tesla is a customer.

Discounting the lack of performance data and despite a ten-percent price differential over existing Li-ion cells, CATL’s batteries may be good investments for the long haul.  Most electric vehicles currently come with an eight-year, 120,000-mile warranty, so ten percent more for 10 times the mileage and a potential eighty years’ usage is a bargain.  (Your batteries will outlast you and your parrot.)

Overcoming the Longevity Gap

Longevity has been a big issue with lithium-sulfur so far.  Mark Crittenden, head of battery development and integration at Oxis Energy, explains that lithium-sulfur cells tend to degrade in a different way than lithium-ion cells, described concisely in his IEEE Spectrum article.

Oxis in cell, pack and casing formats, adding weight to provide protective shielding to cells

The Oxis Energy Technology page indicates a cell life of 250 charge/discharge cycles (the company hopes to double this to 500 cycles “within the next two years.”  Even given the low number, the average light aircraft in this country flies only about 80 hours per year (a terrible utilization rate) and the average light aircraft pilot flies only 40-80 hours.  Even business craft average only about 30 hours per quarter.  This would give about three years’ use at 250 cycles or six years at 500.  If as claimed Oxis batteries are substantially less expensive than Li-ion equivalents, this may be to their advantage.

Other Benefits

Oxis demonstrates their batteries’ ability to take bullets and nail punctures while remaining fully active and not bursting into flames – something with which Li-ion cells don’t fare so well.

Their environmental friendliness comes from their being made of sulfur rather than cobalt and nickel.  Lithium-sulfur cells are claimed by Oxis to be more easily recycled, a major problem for Li-ion cells, which are blamed for major recycling center fires.  Cobalt also bears the burden of being a conflict mineral, extracted in places like The Congo using child and slave labor.

Sulfur is far more abundant and not subject to battles for ownership.  Tenth most common element in the universe and fifth most common on earth, sulfur is found everywhere and has played a part through the history of materials development.

Cells can be fully charged and discharged, unlike lithium-ion cells that cannot be fully charged or discharged without potential damage or shortened service life.

Oxis Powered Aircraft Arriving Soon

Oxis cells are being incorporated in the design of two new craft coming to market soon.  Bye Aerospace, which previously had lithium-ion packs capable of 260 Whr/kg will now have Oxis packs that promise 400 Whr/kg to begin, 470 recently demonstrated and 500 “within a year.”  Oxis hopes for 600 Whr/kg by 2025.

Bye and Texas Aircraft will power their craft with electric motors.  “The all-composite eFlyer 2 is powered by a 120hp (90kW) Rolls-Royce RRP70D electric motor coupled to a 750V battery system. It delivers speeds of over 135 knots (250km/h or 155 mph) and has an endurance of over 3 [hours],” according to Flight Global.  The craft was designed from the start to be electrically powered.

Texas Aircraft’s Colt was introduced at  AirVenture 2019 as a Light Sport Aircraft with the ubiquitous Rotax four-cylinder engine.  It was also shown with a Siemens SP-55D producing 72 kilowatts (96.5 horsepower) AT 3,000 rpm.  Siemens electric aircraft division was purchased by Roll-Royce, so the Bye eFlyer2 and the Colt will share the same motor heritage and similar powerplants.

One can make a reasonable guess as to whether the Rotax or electric version of the Colt is an approximation of the other.  The Rotax engine weighs around 135 pounds and the R-R motor about 62 pounds.  The gas version carries 31.7 gallons of fuel – about 192.5 pounds.  The electric version’s 90 kilowatt-hour battery pack will weigh about 225 kilograms, or 495 pounds.

495 pounds of batteries minus the 192.5 fuel weight gives 302.5 pound difference.  Discount the electric motor weight vs. the gas engine and that gives up 73 pounds, ending up with a roughly 230 pound penalty for the electric Colt.  We have seen, though, that electric motor torque might be an equalizing performance factor, although this editor needs more study on the matter.

Texas Aircraft and Pipistrel will have electric and gas versions of three different models (the Alpha and Velis for Pipistrel).  These craft should provide excellent points of comparison.

Related Uses

Oxis sees its batteries as plausible in ground, air, and unmanned aerial vehicle applications, and others having experimented with lithium-sulfur have demonstrated reliable use.

A Parting Gift

Oxis has a 2018 brochure on line, extolling the virtues of their product.  One promise is eye-opening, comma splice and all.  “OXIS will be instrumental in moving the aviation sector away from lead-based fuel, the objective is to extend flight time eight fold by 2025, without increasing the weight of the aircraft.”

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