Doing More with Less – BLI on a Big Scale

Hybrid and electric cars sell because they lower operating costs for the owner.  Designers and manufacturers sort out ways to increase efficiency, including streamlining, using low-rolling-resistance tires, and making structures lighter.  An added technology, boundary layer ingestion (BLI) may add to aircraft efficiency.

NASA and industry leaders are working on equivalent solutions for aircraft, and airplanes will end up as different from today’s designs as Toyota Priuses and BMW i3s are from Ford Falcons or Chevrolet Corvettes.  NASA proclaims, “An aviation renaissance, one focused on energy efficiency and economic impact, is on the horizon, and it’s changing how engineers look at aircraft power and design.”

STARC-ABL configuration uses smaller jet engines under wings, electric motor in tail to reduce drag

Jim Heidmann, a manager of NASA’s Advanced Air Transport Technology Project (AATT), says, “I feel we are at a tipping point in commercial aviation.  We are exploring and developing game-changing technologies and concepts for aircraft and propulsion systems that can dramatically improve efficiency and reduce environmental impact and accelerate the introduction of new aircraft.”

Think of incredibly efficient aircraft such as Eric Raymond’s Sunseeker Duo, or Stuttgart University’s e-Genius.  Both fly on low power: (22 kilowatts – 29.4 horsepower) transport Eric and wife Irena around Italy and Switzerland), and both transcend the heights with marvelously little noise.

Now, think about scaling that efficiency to 100-or-more-passenger airliners.  The more efficient craft will look different, be lighter, and use different mechanisms for propulsion.  To achieve the quieter, lower emission, more efficient future aircraft, NASA is working with industry and academia to craft “different fuselage shapes; longer, skinnier and more blended wings; innovative materials and components; and highly-integrated propulsion (engine) systems.”

STARC – Swallowing Its Own Boundary Layer

NASA’s experimental outings include distributed propulsion and low-boom” supersonic aircraft, but we’ll first look at a twin-jet airplane with an electric fan in its tail.  The STARC-ABL (single-aisle turboelectric aircraft with an aft [at the rear of the aircraft] boundary-layer propulsor) looks like a Boeing 737, but with smaller engines under the wings and a noticeable cylindrical bulge under its T-tail empennage.

The wing-mounted engines produce 80-percent of the thrust required for takeoff and 55 percent at cruise.  The tail-mounted boundary-layer ingestion turbofan provides the remaining thrust.  According to researchers, this combination should reduce fuel consumption by around 10 percent.

NASA’s presentation gives a high level of detail about the technology involved.

Smoothing the Way for a Tail Propulsor

Engines hanging under the wings, as they do on most Boeing and Airbus products, present a neat aerodynamic advantage, skimming through undisturbed air.  A turbine at the rear of a fuselage, as on a 727 or DC-10, has to deal with turbulence coming off the fuselage.  Wind-tunnel tests at NASA Glenn are showing how to lower drag with this configuration.

Something counter-intuitive takes place at this point.  NASA explains, “With the engines in this location, the slower, boundary layer air enters the engine – or is ingested, as in boundary layer ingestion – and is then accelerated with the rest of the air passing through the engine and exhausted out the back.

“It doesn’t matter if the incoming boundary layer air winds up being compressed, mixed with fuel and burned to become part of the hot jet exhaust, or if the air flow bypasses around the engine core, through the fans and out the back.”

While this doesn’t create more (or less) thrust, it does reduce drag, allowing the under-wing engines to produce less power and use less fuel.

Testing with a Life-Size Airplane – It’s NEAT

Going beyond wind tunnels, NASA is constructing a full-sized test apparatus, the NASA Electric Aircraft Test (NEAT) test bed at Glenn Research Center.

BLI prototype in NEAT test bed

The 24 megawatt system is not the largest such test bed, but adequate for the needs of the single-aisle tests.

Robert Jankovsky, NASA Engineering and Safety Center (NESC) Chief Engineer, sees future benefits and expanded horizons for this program.  “As we move forward, we’d like to further develop the powertrains for these and any other concepts that may prove viable by building and testing them at NEAT and other NASA facilities.  We’ll identify key performance parameters for components such as motors, generators and power electronics, and any wind tunnel, altitude and other ground tests and flight demonstrations that are appropriate.”

Doubling Down along Similar Lines

Aurora Flight Science’s “Double Bubble” D8 has been tested in an MIT wind tunnel, and uses boundary layer air from the top of its double-wide fuselage to feed its engines.  Boeing recently acquired Aurora, so it will be interesting to see how they meld the technologies.  The video highlights Aurora’s contribution, but can be seen to be a close match to NASA and Boeing’s work on a single-aisle solution.

Aurora explains, “The efficiency gains of the D8 are the result of a tightly integrated design approach. Increased lift generated by the wide “double-bubble” fuselage means smaller wings are needed to carry the vehicle’s weight, resulting in less fuel to fly a given mission. When the engines are integrated into the back of the fuselage, thrust requirements are further reduced due to efficiencies from Boundary Layer Ingestion (BLI). This means that smaller engines can be used, which reduces weight and fuel even further. This cycle of repeated optimization is what gives the D8 such groundbreaking efficiency.”


In the next decade, your new car may not only be electric or hybrid, but solar powered.  A speaker from an Italian auto firm told a symposium your editor attended five years ago that solar roofs on cars could provide up to 30 free kilometers for an electric car each day.  That 18 miles would be a gift indeed, but at least three innovators are working toward making that an underachievement.

Sono Motors and their Sion

Sono Motors, headquartered in Munich, Germany, used crowdfunding to build their prototype and publicize their five-seat, partially solar powered vehicle – Sion.  Sion comprises several surprising elements, including polycarbonate shielded solar cells integrated into the simple, wedge-shaped body design, an interior air-cleaning system based on living plants, and an ingenious group of communications and charging systems.

Sono Sion incorporates solar panels into simple design

To keep the cost within the 16,000 euros promised in their fundraising campaign, the designers left out the 30 kilowatt battery, good for 250 kilometers (155 miles).  This seeming lack enables buyers to purchase a pack at current prices (and with current capabilities), or lease a battery pack that would be upgraded regularly with the latest, greatest technology.

A Trans-Australia Cruiser Becomes a Daily Driver

Australia just staged the World Solar Challenge, a cross-country race for solar cars, part of a heritage of 13 solar races dating back to 1987.  The winner in the Cruiser class may be going for commercialization, too.  More swoopy than the Sion, Stella is as five seater as well, and the video from the Eindhoven Technical University in the Netherlands emphasizes its virtues as a family car.

More a purely solar car than the others, Stella has a 12.5 kilowatt-hour battery, and relies on its roof-top solar cells to give it its 130 kilometer per hour speed.  Solar Team Eindhoven shares its design philosophy in this summary:

“Our solar car is unique because she is a five-seater family car which focusses around efficiency without losing practicality. Through a smart charging and discharging system she charges the battery when the demand of energy from the grid is high and vice versa. Any surplus of energy generated can easily be supplied back to the grid. Whilst driving, the car gives subtle feedback on the driving behavior of the user. In addition, through the solar navigator she gives advice on efficient routes, efficient driving speed and the best parking location to generate as much solar energy as possible.”

An American Effort

And in San Francisco, Otherlab is developing a solar-powered vehicle through a subsidiary, Lightfoot Electric.  The project leaders explain the car in this terse form:

“Lightfoot Electric is building the next paradigm in urban transportation, the solar-electric hybrid car. Because cars are built for highways but we live in cities. Because 80% of trips taken in the US are less than 20 miles. Because lithium-ion batteries and brushless motors. Because the sun isn’t going anywhere fast, but you are. Hassle free. Guilt free. Carbon free. 3,500 hundred miles a year free.”

Lightfoot solar car will be boxy, simple, according to sketch

Otherlab describes the car as being “built like a helmet to protect you and your family,” and being “right-sized” and “digitally fabricated.”  They haven’t released photos or other material on the car, but you can sign up for a newsletter to keep abreast of the project.

Application to Future Aircraft

With automobiles showing that solar cells can add range to their daily use, aircraft, with greater surface areas and the ability to fly above clouds, can definitely benefit from lower-cost solar cells such automotive uses may promote.  Developers, with a larger market to promote, will probably invest in increased efficiency for their vehicles.  Automated manufacturing techniques created for ground vehicles may also apply to future flight.  Lighter, stronger, more efficient vehicles will benefit us all, and the planet.


Peter Sripol is part of FliteTest, a group that sells electric model aircraft and components and produces some wild and wooly YouTube videos of their exploits.  The group’s products are mostly budget items, with simple aircraft quickly constructed the norm.  One example, the Simple Solar radio-controlled plane, can be built for under $60, and flies on two coreless motors.  Flite Test has quick build kits and FPV (First Person View) radio systems that allow a pilot to view, through an on-board camera, what a (really tiny) person on board the model would see.  This level of miniaturization and commodity-level pricing allows FliteTest to provide STEM (Science, Technology, Engineering and Math) kits to schools at the grade and high-school levels.

A $60 solar airplane from FliteTest

MTV Meets Howard Hughes

One of its newest members, Peter has jumped on FliteTest’s seeming willingness to try anything at least once.  Putting together extremely large models from foam and tape, it probably was only natural that he would make a modest jump into creating a real airplane.  Like the model products, his design is boxy and a bit steampunk.  Home insulation foam, large chunks of perforated thin plywood, and a pair of large model airplane motors form the basis for the low-budget flying machine.

Peter Sripol with a large foam, radio-controlled twin-motor cargo model


Peter made a series of YouTube videos showing the creative process involved, building approaches and finally the long-awaited flight test (FliteTest?).  Peter’s frenetic pace and MTV-style editing of his project might be almost wearying to the casual viewer.  But he (and his viewers) has breaks in which helpful – and sometimes concerned – viewers provide Tweets of encouragement and caution.  Peter takes the critiques to heart and incorporates the most helpful suggestions into his final product.

The Basis of Design and the Introduction of a Pair of Canine Mascots

Peter’s videos include a pup who literally grows on the viewer, and like his master’s creation, achieves a great screen presence.  (The older black and white dog has to play a supporting role in the drama.) These seven short pieces cover a lot of ground, and show the many little details that confront a person crafting an airplane from “scratch.”  Starting on August 12 and finishing with test flights on October 31, the project is truly a “quick-build” enterprise, with trips to Lowe’s and Home Depot instead of Aircraft Spruce for supplies.

Part 1 introduces the protagonist and a model of his dream ship.  Unfortunately, a final flight causes Peter to lose control and crash the airplane.  In a moment we hope is not prescient, the model pilot’s head is ejected from the cockpit.

Part 2 depicts the rapid pace of laying out, cutting, and assembling the fuselage.  One gets the impression that years of building everything from models powered by spinning Kentucky Fried Chicken tubs (Magnus effect) to models literally made of food (most crashing into edible chunks) has given Peter the impetus to try just about anything at least once.

Part 3 gets into details of the cockpit and expands on the theme of a boy and his dog.  It includes techniques not covered in most handbooks on aircraft construction.  Combining 3D printing and prehistoric fabrication approaches, this section might challenge the builder who’s put together a kitplane following the plans to the letter.

Part 4 gets us through fiberglassing the fuselage and beginning wing construction.

Part 5 shows wing construction and some of the shortcuts Peter uses, including drilling through seven pieces of metal at once.  He also uses stacked boxes of noodles, rather than sand bags to stress test his wings.

Part 6 gets us to the installation of Giant Motors – a pair of Turnigy Rotomax 150’s.  They purportedly replace 150 cc fueled engines, glow-plug fired units that burn a mixture of methanol, castor or synthetic oil and nitromethane.  One can readily see that electric motors will make fewer immediate fumes.  WW I pilots, incidentally, used to have severe bouts of gastric distress from breathing castor oil fumes cast off by their rotary engines.

Part 7 ends with some triumphant test flights.  Peter dresses in the style of Howard Hughes with a leather jacket and thin necktie, appropriately Aviator-like for his moment of truth.  Tracking shots made from drones hovering overhead would make Martin Scorsese proud.

Peter shows that one can build and fly an electric airplane on almost steampunk technology, with a little help from 3D printers and CNC cutters.  His willingness to accept advice from a large number of followers is to his credit, and we hope his GoFundMe requests for ballistic parachute money will help him clear the field’s perimeter and attain greater than ground effects heights.


UAVs Push Endurance Limits

Three unpiloted aerial vehicles of wildly different configurations recently set endurance marks, each a “personal best,” with some achieving world records.  The varying designs show what can be achieved by careful aerodynamic design and efficient powerplants.

Aerovel Flexrotor Sets VTOL Endurance Mark

Not just a fair weather UAV, Aerovel’s unmanned Flexrotor, named for the sea nymph Actaea, “lifted off into a grey and rainy morning with 7.5 kilograms (16.5 pounds) of fuel onboard”.  According to the company, “It transitioned from hover to wing-borne flight, and soldiered on through a showery day, a blustery night, and then another day in the breezy and unsettled air behind a cold front. As dusk fell it transitioned back to hover, and dropped gently down onto a 12-foot square helideck underway at 8 [knots] (9.2 mph). Time from launch had been 32 hours and 8 minutes. More than 3 hours’ worth of gasoline remained in the tank.”

The press release doesn’t say where the flight took place, although the firm’s Columbia Gorge home often has weather approximating the event’s description.

Dr. Tadd McGeer, founder of the White Salmon, Washington firm, explained that, “the first day was a little turbulent, and after going through the cold front we had 20-30 kt wind and lots of convection. A sailplane pilot would have used it to good effect, but Actaea was holding constant altitude and so gave up a few percent of range fighting the ups and downs.  Performance was otherwise right on expectation.”

Actaea photographed by another Flexrotor flying formation with it during record flight

Not only sporting a more powerful diesel engine, but showing its tail feathers that spread out to form a landing platform, Actaea does not need the comb-like landing platform necessary for Flexrotor operation previously.  The tail-landing setup allows launching from an area as small as a four-meter (13 feet) skiff, even in turbulent waters.

Able to carry a wide range of sensors and cameras, Flexrotors provide a versatile platform for a variety of applications.  The demonstrated ability to take off and land vertically, coupled with  high endurance, makes the machine a useful tool for exploration and surveillance.

AtlantikSolar Checks out Arctic Glaciers

AtlantikSolar, a product of The Autonomous Systems Laboratory (ASL) at Switzerland’s ETH Zurich (the Swiss Federal Institute of Technology), was originally, and probably still is, intended to make an autonomous flight across the Atlantic Ocean.  It’s made flights up to 81 hours, and been used to find refugees in tough situations with its suite of miniaturized sensors and cameras.

On June 20th, as part of ongoing testing of this “perpetual” flying machine, team members from the Autonomous Systems Laboratory (ASL), designers of the drone, and glaciologists from ETH Zurich combined forces to monitor glaciers in Greenland.  Unfortunately for the planned 24-hour test, fog rolled in at the six-hour mark, and persisted until after 13 hours in the air, the drone had to be retrieved.  Enough charge was left in the battery to have allowed a full 24-hour flight.

AtlantikSolar faced the strongest winds and gusts of its career on July 3, flying into a research area while confronting up to six meters per second (1,181 feet per minute) vertical gusts and a sustained tailwind of 15 meters per second (2,953 feet per minute – 33.5 mph).  After flying for five hours and covering 230 kilometers (142.6 miles), the drone landed still nearly fully charged.  Even in the high latitudes, with the sun on the horizon, AtlantikSolar’s solar cells apparently managed to keep its batteries topped up.

A view down the wing of the drone – solar cells in full view.  AtlantikSolar over Greenland’s Arctic wastes, the six-kilogram (13.2 pound) craft surviving high winds and turbulence

During the flight, “AtlantikSolar’s mapping revealed a large crevasse upstream at the front [of the glacier]. A few days later, some glaciologist colleagues went to Bowdoin and kept monitoring the propagation of the crack, until it suddenly collapsed.

Data collected during the flight may enable scientists to anticipate other such events.  “All together, we now have a unique set of data – describing all the fracturing phases – for improving the numerical modeling of calving, a complex and still not fully understood mechanism, which plays a major role in the sea level rise.”

Vanilla VA001

A design that would have delighted Bruce Carmichael, one of the leading experts on low Reynolds number aerodynamics, Vanilla’s VA001’s 36-foot, high-aspect-ratio wing and carefully streamlined laminar-flow fuselage does all it can to reduce drag to an irreducible minimum.  Two pylons hold the wing above the fuselage, reducing interference drag between the two largest components on the aircraft.

Designed, built and flown by a five-person team, Vanilla’s VA001 lives up to its “vanilla” name as a generic unmanned air system that can be customized for different missions.  Propelled by a small diesel engine, the craft can carry a 1.1 cubic foot, 30-pound payload, and power on-board needs with up to 800 Watts.

Its sleek shape allows planned-for trips of up to 10 days at altitudes up to 15,000 feet, the airplane can loiter at 55 knots (63.25 mph) and “dash” at 75 knots (86.25 mph).  In its tenth flight starting October 18, the plane covered 7,000 miles in the next five days.  VA001 landed autonomously on October 23 following a “quite boring” flight.  According to Chief Engineer Neil Boertlein, “The plane did what it was designed to do and landed ready to go right back into the air again.”

Cruising for five days above Wallops Island, Vanilla’s VA001 etched great circles in the sky

Test Director Jeremy Novara added, “Previous flights had already validated our performance predictions, but this flight really demonstrated the reliability and ease of operation that a low-cost persistent unmanned aircraft can obtain.”

Like the Flexrotor and AtlantikSolar, VA001 can carry a complement of electronics, including electro-optical and infrared imagers, synthetic aperture radar, SIGINT systems (for gathering SIGnal INTelligence from enemy communications), and a variety of communications nodes.  Its ability to stay aloft for days makes it a good candidate for military missions where persistence is a premium, and for hovering over fires or disaster zones where real-time imaging will be invaluable.

The flight crew with the airplane after landing, October 23, 2017. From left to right: Shannon Cardin, Daryl Perkins, Phillip Barnes, Jeremy Novara, Daniel Hatfield, Kyle Cantrell & Neil Boertlein. Photo credit NASA/Terry Zaperach

CEO Tim Heely stated, “We have begun to fully demonstrate the viability of this ultra-long endurance aircraft system and are anxious to test new payloads and realize capabilities heretofore unimagined. We are excited to bring a new affordable, easily sustainable capability to the quickly expanding Unmanned System environment.”

The company plans to begin production in the coming months, and is open to teaming with payload providers.


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Hoversurf and OTSAW Patrol the Skies of Dubai

Hoversurf’s recent announcement of its use by Dubai police to patrol the streets and skies of the capital city brings forth several questions.  With Dubai and other Emirates readily encouraging new modes of transport, including sky taxis and possibly Hyperloop trains, the country seems set to lead a transportation revolution in the 21st century.

Already, style leaders and plutocrats crowd the streets with Lamborghinis and Bugattis: the police force fielding equally formidable patrol vehicles to control over-eager drivers.  Police inventories include a Brabus-tuned 690 horsepower Mercedes Geländewagen capable of off-road desert sorties, and at least one $1.6 million Bugatti Veyron for on-road speeders, along with a Porsche 918 and various Aston Martins.  Several other supercars ensure a fairly even pursuit against Dubai’s party crowd if necessary.

Not so fast and furious after October 15, speed limits on Sheikh Mohammed bin Zayed Road (311) and Emirates Road (611) have been reduced to 110 kilometers per hour (68.2 mph) hardly sufficient to clear carbon-laden valves in the country’s supercars, and making it much easier to ride herd on the eager throngs.

Which brings us to the nation’s potential overflight and oversight problem.  With eHang’s 184 and Volocopter’s 18-rotor 2X in trials around the impossibly high skyscrapers, how will their limits be enforced?  First, since most flights will be autonomous, what’s the need?  Second, since the Dubaian police will limit their Hoversurfs to 70 kilometers-per-hour (43.4 mph), how can they be of any use chasing down errant Fast-and-Furious wannabes?

Apparently, the police version of the Hoversurf Scorpion 3 will be limited to about five meters altitude (16 feet), and have only 25-minute’s endurance.  This will limit its use to hopping over traffic jams and delivering an officer to the scene.

Bigger Hoversurfs on the Way

Larger Hoversurfs are on the way, with one able to carry a 90 kilogram (198 pound) load, roughly equivalent to the weight of a pilot.  With no redundancy in the power system, a ballistic parachute might be the only means of a less-than-tragic crash, although your editor does not want to be caught under the 400 pounds total weight (estimated) coming down at even reduced speeds.

Interestingly, the company claims to have developed larger vehicles.  “Our company designs and manufactures cargo drones for various purposes that have already proven their efficiency in transport and premises monitoring, Arctic and terrain reconnaissance, geological exploration, delivery of equipment to remote locations, rescue & evacuation operations with the units’ carrying capacity ranging from 90 to 2,500 kg.”

Hoversurf Drone Taxi

With the same power layout (four motor-driven propellers at the corners), but with added wings and a pusher propeller, the Drone Taxi version, according to the makers, should be able to hit 300 kilometers per hour (186 mph) and travel 400 kilometers (248 miles), enough for a quick trip to neighboring Emirates.

Hoversurf Drone Taxi has a rotor at each corner, but also wings and a pusher propeller

Purposes for Hoversurf’s machines could diverge in a dark wood, heading toward either Jetson or Bladerunner futures.  As with most technology, the ethical construct surrounding its use depends on the depth of understanding of the user.

Hoversurf’s floating piston engine for possible hybrid arrangement in Drone Taxi. Few details are otherwise available

OTSAW and New Ways to Telecommute

In a related development, Dubai police are deploying OTSAW Digital’s O-R3 patrol vehicle, a self-driving, sensor-laden machine that carries its own quadrotor drone.

OTSAW O-R3’s myriad cameras and sensors

According to the firm’s Linked In page, “About the size of a child’s electric toy car, the driverless vehicles will patrol different areas of the city to boost security and hunt for unusual activity, all the while scanning crowds for potential persons of interest to police and known criminals.  Even with facial recognition attaining ever-better levels, one must still question probable cause or presupposition of guilt from evidence captured by a drone’s camera.

For that matter, will we feel “free” while knowing we are under constant oversight.

Not a Total Digression

OTSAW has a nifty item for those who might want to sleep in on meeting day.  Its Double is a roll-around dolly with a flat screen perched atop a stalk.  A person’s face can double for the missing person, making a sales pitch or fielding questions.  Perhaps, as with some court hearings these days, Double could fill in for the accused, electronically make bail and roll out of the courtroom – with the accused literally having never faced justice.  Trying it out will cost a purchase price of about $3,300.

OTSAW’s Double will double for user, taking his or her place in meetings. On-board camera allows visual interaction with real people in room – or other Doubles

Plunging Into the Uncanny Valley

Your editor tosses this seeming digression in response to a similarly related story in the day’s news.  Saudi Arabia has declared a robot to be a citizen (Interesting in a country that has just given its women the right to drive).  Sophia is almost charming, even with the weird “hairdo.”  She speaks clearly, although a bit mechanically.  One wonders if we’ve come to the “uncanny valley” referred to by robot experts, in which robots become just “real” enough to attain a certain creepiness. See what you think of Sophia, and ask yourself about the implications of her treating us as nicely as we treat her.  Do we want our automated machines to be all that emotional?  What if those emotions are included in the programming for surveillance drones or traffic cop avatars?  Or in the automated cars or sky taxis we trust with our lives?


Triplanes were popular in World War One because they allowed great maneuverability for dog-fighting, a supreme survival necessity.  Their success in designs by Fokker and Sopwith, among others, gave them a certain panache.  Now, a Bristol, England-based company hopes to revive the triplane as a commuter aircraft ready to fly from regional airports.

Triplanes – not just an antiquated bit of nostalgia

Faradair®, named after English physicist Michael Faraday*, hopes to craft an airplane that will allow flight from smaller regional airports and compete with even well-established rail service.  Their craft, BEHA – Bio-Electric Hybrid Aircraft, will fly six to eight lucky passengers on a quiet inter-city ride powered by a 300-horsepower internal combustion engine and two electric motors in a parallel-hybrid arrangement.

Neil Cloughley, Managing Director and Founder of Faradair, wants to return Britain’s regional air services to a point where they were between WWI and WWII, when a small group of passengers could board a DeHavilland Dragon Rapide for a leisurely and sight-filled journey over England’s green land.  Cloughley notes the passing of regular national air service with this hoped-for result of his new airplane design: “But most importantly, we remember the likes of the de Havilland Dragon Rapide and Dove, these were early airliners that carried passengers between cities more regularly than aircraft operate today and yet these aircraft operated over 80 years ago.  So all of us at Faradair believe that we need to return to the skies on a regional basis, to improve quality of life, reduce congestion, reduce journey times, reduce emissions thereby increasing competition and choice within commuter networks to lower costs.”

The web site explains, “In the UK between 2015 and 2016, 4.5 million rail journeys were made per day, delivering over £9billion in revenue, as compared to just over 56,000 passengers using air terminals each day for national or domestic flights.”  Faradair concludes, “We can do better.”

Powering BEHA

Faradair partners with Prodrive to develop an internal-combustion core unit for BEHA.  Prodrive is a world-class racing engine producer, fielding cars at the highest levels of performance.  “Since 1984 Prodrive has won six World Rally titles, four Le Mans 24 Hours titles, three FIA WEC titles, four British Touring Car Championships and the Le Mans Series among many other national and international race and rally series.”  The group recently ran a sub-seven-minute lap of Nurburgring’s Nordschleife in a Subaru WRX STI.

They are intent on producing a “clean sheet” 300-horsepower engine that can run on Jet-A or biofuels, with all the reliability of conventional aircraft engines and at similar prices.  This unit will be teamed with twin electric motors which will produce an additional 300 horsepower.

Batteries will be a small part of the package, enabling only ten minutes power on their own, a bit like smaller hybrid packages such as Axter and several similar systems of varying sizes.

Electric takeoffs could hush operations to make them amenable to close-in urban airports, and provide a safe let-down if the ICE failed for some unforeseen reason, much like the Axter and other hybrids.  The fixed landing gear removes one item from the landing checklist in emergencies.

A Staggering Arrangement of Wings

One advantage biplanes and triplanes have is that their wings can be staggered, offset along the fuselage to prevent aerodynamic interference between the pressure distributions of upper and lower wings.  It also helps locate the center of gravity in the most advantageous spot.  Usually, the wings have different angles of attack (decalage) to allow them to stall at different speeds.  This provides an early stall warning and a gentle break, wing by wing before all lift is lost.


Great amount of open space between wings allows for undisturbed airflow over each

The three wings of the BEHA are positively staggered (top wing foremost, lowest wing rearmost) with ample space for their solar cells to collect rays while the wings operate in mostly undisturbed airflow.  Flights in several biplanes have convinced your editor that decalage provides a stable pitch “feel” to the airplane.

With a projected cruise speed “faster than a Chinook helicopter” (165 knots or 190 mph), BEHA should have excellent slow-speed capabilities.  “The aero engineers and professors at Cranfield University were surprised at the configuration performance capability, especially with the impressive slow speed flight capability and low stall speed characteristics.  The airframe is currently in the final phases of airframe optimization and the results will be revealed in the next 12 months.”

 An interesting Tail

“Shrouding” the propeller in a duct that can also vector thrust sideways or up and down, the tail section augments thrust and adds pitch and yaw control.  The ducting may reduce propeller noise and make the airplane’s passage a quiet one.

Faradair BEHA quietly overseeing the veldt. Note segmented sections of tail shroud for directional control

Beyond its planned role in commuter flight, BEHA could be useful for sneaking up on poachers and performing other wildlife conservation functions.  It might also find favor as a VIP transport, or for uses in police work, or on floats as a low-cost alternative to helicopter transport to oil rigs.  The designers see a larger variant holding up to 30 passengers and providing longer-range trips.

Certainly, the idea of regional, low-hassle flights has occurred to many designers, and we’re seeing the potential for a highly-competitive market in this arena.  BEHA is an interesting addition to this renewed market.

 *Wikipedia lists the following attached to the inventor’s name:

Faraday’s law of induction (part of the invention of the induction motor)
Faraday effect
Faraday cage
Faraday constant
Faraday cup
Faraday’s laws of electrolysis
Faraday paradox
Faraday rotator
Faraday-efficiency effect
Faraday wave
Faraday wheel
Lines of force


Better Battery Materials – Asphalt?

Asphalt, Graphene, and a Lithium Coating

Mike Williams, reporting for Rice University in Houston, Texas, writes, “A touch of asphalt may be the secret to high-capacity lithium metal batteries that charge 10 to 20 times faster than commercial lithium-ion batteries, according to Rice University scientists.”

We’ve written about James Tour and his laboratory before.  He and his students come up with a plethora of new energy ideas and are able to demonstrate some exciting outcomes.  His latest effort mixes asphalt with conductive graphene nanoribbons, and then electrochemically coats the composite with lithium metal to form a battery anode.

Scanning electron microscope images show an anode of asphalt, graphene nanoribbons and lithium at left and the same material without lithium at right. The material was developed at Rice University and shows promise for high-capacity lithium batteries that charge 20 times faster than commercial lithium-ion batteries. Courtesy of the Tour Group

The anode, when combined with a sulfurized-carbon cathode, was used in full batteries for testing.  The results seem a bit incredible, with the ability to charge 20 times faster than commercial lithium-ion batteries.  Being able to “refill” your electric car or airplane in five minutes rather than two hours or more would make electric vehicles practical alternatives to their fossil-fuel-powered cousins.

After 500 charge-discharge cycles, the batteries demonstrated a high-current density of 20 milliamps per square centimeter and a high-power density of 1,322 Watts per kilogram and high-energy density of 943 Watt-hours per kilogram (compared to 250 Watt-hours per kilogram for “conventional” Li-ion cells).  This nearly four-fold increase in energy density would enable longer range or light battery weights for aeronautical applications.

Coulombic efficiency is relatively stable over a range of high discharge rates, but appears to develop fluctuations after the 60th cycle.  Courtesy of the Tour Group

To sweeten this already candied deal, the carbon-lithium combination prevents the formation of dendrites, those tooth-like growths that puncture separators in more conventional lithium cells and cause shorts and even fires.

Icing on an already well-frosted sweet, the new composite is simpler than other approaches, according to Tour.  “While the capacity between the former and this new battery is similar, approaching the theoretical limit of lithium metal, the new asphalt-derived carbon can take up more lithium metal per unit area, and it is much simpler and cheaper to make.  There is no chemical vapor deposition step, no e-beam deposition step and no need to grow nanotubes from graphene, so manufacturing is greatly simplified.”

Simplification of manufacturing, combined with extremely high performance, improved safety, and quick charges, makes this new battery something to watch.

ACS Nano Paper

Tuo WangRodrigo Villegas SalvatierraAlmaz S. JalilovJian Tian, and James M. Tour authored a paper on their accomplishment for the ACS Nano journal.

The abstract sums it all up.  “Li metal has been considered an outstanding candidate for anode materials in Li-ion batteries (LIBs) due to its exceedingly high specific capacity and extremely low electrochemical potential, but addressing the problem of Li dendrite formation has remained a challenge for its practical rechargeable applications. In this work, we used a porous carbon material made from asphalt (Asp), specifically untreated gilsonite, as an inexpensive host material for Li plating. The ultrahigh surface area of >3000 m2/g (by BET, N2) of the porous carbon ensures that Li was deposited on the surface of the Asp particles, as determined by scanning electron microscopy, to form Asp–Li. Graphene nanoribbons (GNRs) were added to enhance the conductivity of the host material at high current densities, to produce Asp–GNR–Li. Asp–GNR–Li has demonstrated remarkable rate performance from 5 A/gLi (1.3C) to 40 A/gLi (10.4C) with Coulombic efficiencies >96%. Stable cycling was achieved for more than 500 cycles at 5 A/gLi, and the areal capacity reached up to 9.4 mAh/cm2 at a highest discharging/charging rate of 20 mA/cm2 that was 10× faster than that of typical LIBs, suggesting use in ultrafast charging systems. Full batteries were also built combining the Asp–GNR–Li anodes with a sulfurized carbon cathode that possessed both high power density (1322 W/kg) and high energy density (943 Wh/kg).”

Tour’s Astounding Repertoire – Science You Can Dance To

James M. Tour has a wide-ranging set of accomplishments, including over 630 research publications and over 120 patents.   According to Rice University, he “was inducted into the National Academy of Inventors in 2015. Tour was named among “The 50 Most Influential Scientists in the World Today” by in 2014; listed in “The World’s Most Influential Scientific Minds” by Thomson Reuters in 2014; and recipient of the Trotter Prize in “Information, Complexity and Inference” in 2014; and was the Lady Davis Visiting Professor, Hebrew University, June, 2014. Tour was named “Scientist of the Year” by R&D Magazine, 2013. He was awarded the George R. Brown Award for Superior Teaching, 2012, Rice University; won the ACS Nano Lectureship Award from the American Chemical Society, 2012; was the Lady Davis Visiting Professor, Hebrew University, June, 2011 and was elected Fellow of the American Association for the Advancement of Science (AAAS), 2009. Tour was ranked one of the Top 10 chemists in the world over the past decade….”  The list of accomplishments and awards goes on at length.

Nanokids used to help teach nanoscience, technology to K – 12 grades

Not content to guide few lucky graduate students through the intricacies of exploration, he’s expanded his teachings into new areas.  “For pre-college education, Tour developed the NanoKids concept for K-12 education in nanoscale science, and also Dance Dance Revolution and Guitar Hero science packages for elementary and middle school education: SciRave( which later expanded to a Stemscopes-based SciRave. The SciRave program has risen to be the #1 most widely adopted program in Texas to complement science instruction, and it is currently used by over 450 school districts and 40,000 teachers with over 1 million student downloads.”

Let’s just hope his batteries become commercialized soon.


Partnering with easyJet, a UK-based budget airline, to build an electric airliner capable of carrying 150 passengers on sub-two-hour flights, Wright Aero will substitute electrons for liquid fuel on one-fifth of EasyJet’s trips.  Finding a ready collaborator in easyJet’s Carolyn McCall, Engler has a partner who is already making inroads into making jet flight cleaner.  “’We can envisage a future without jet fuel and we are excited to be part of it. It is now more a matter of when not if a short haul electric plane will fly,’ said EasyJet CEO McCall,” in an interview with The Guardian.

Wright Electric’s airplane for easyJet will cover one-fifth of the airline’s short-range flights

Engler added, in his latest Wright Weport:

“First, the context is on Wednesday easyJet announced a partnership with us during their Innovation Day….  We could not be more excited!

Skilled team assembled Wright Electric’s model in time for Innovation Day unveiling

“(Note: if you have a second, would you mind posting the article on facebook/twitter? We’re hoping it reaches as many battery researchers’ eyes as possible! Thank you in advance!)

“Second, our main takeaway is easyJet is committed to green. In addition to the partnership with us, they announced:

  1. “Electric aircraft tugs for their fleet of 60 planes at Gatwick airport.
  2. “A partnership with Safran to trial hydrogen fuel cell tugs.
  3. “An order of 98 A320 neos with 15% fuel savings.”

EasyJet seems to be committed to cleaning up all aspects of its operations.  By going to electric tugs, easyJet benefits from lower operating costs and increased reliability.

easyJet’s use of TPX-100e electric tugs will help overall emissions at Gatwick Airport

The TPX-100-E, an electric towbarless tractor designed for pushback of most commuters, and single-aisle aircrafts up to 100 tons, from SAAB 2000 to BOEING B757 (100 tons max.), uses a “unique AC/DC technology,” and fits all nose landing gears (NLG).

Beyond that, easyJet is seemingly interested in cost-saving technology that also allows cleaner operations.  The airline seems to be succeeding in its efforts, including being able to bring forward Engler’s ambitious development program.  Starting a few years ago with early attempts to electrify a Piper Cherokee, a simple four-seat light aircraft, Engler realized that it was more worthwhile and potentially lucrative to go after a larger market.  Let’s hope that his and Ms. McCall’s approach pays off.  It will mean even cheaper, cleaner short-range flights for all.

easyJet’s distributed electric power system

And all that technology will come back in future EAA homebuilt aviation projects.  For many of us, that might be the greatest benefit.  We’ll see those electric Cherokees and Cessnas sooner than we might believe.  After all, NASA is working with similar programs on its X-57 Maxwell program and David Ullman is crafting a two-seat distributed thrust machine in his home hangar.


Boeing made two announcements this week that show the maker of large aircraft willing to investigate niche markets at smaller scales and with more personal service for flyers.  Both involve electric power and the potential for automated flight.

Zunum To Fly by 2020, In Service by 2022

Zunum Aero, the Boeing- and Jet Blue-backed regional airliner startup, will begin development of a 10-to-12 passenger airplane, hybrid powered with large electric ducted fans at the rear of the fuselage.  Having flown on earlier examples of 10-passenger “airliners,” your editor welcomes this smaller package.  Ford Trimotors and DeHavilland Dragons carried passengers in the 1930s, with simple accommodations and window seats for all.  The single-aisle made boarding and deplaning easy and quick, and the low altitudes and slow speeds gave a great sense of engagement with the passing scene.

Zunum sees a broad range of smaller airfields as ideal for its short-haul machines

Zunum provides a modern adaptation of this personalized service and opens many otherwise underused airports for new use.  It brings back the regional airport as a hub for smaller cities and enables simpler, more efficient travel.  Zunum sees a rare opportunity for its airplanes to reinvigorate such markets.  “Our stock of 13,500 airports is the largest in the world, yet just 140 of the largest hubs carry over 97% of air traffic. This has left many of us with long drives to catch a flight, while on shorter trips we skip air travel altogether. Communities without good air service also struggle to attract investment and create jobs.”

Zunum sees its products reducing emissions.  Short-haul flights account for 40 percent of all aviation emissions, according to Zunum.  They see their electric aircraft eliminating those “within twenty years.”  Beginning with hybrid systems, the aircraft will become more fully battery powered as advanced energy storage devices become available. Whether hybrid or fully electric, Zunum craft will have quickly swapped battery packs in their clean wings.

Zunum’s 10-12 seat regional airliner will initially be a hybrid, with increasing reliance on batteries as technology improves.  Operating cost of 8 cents per seat mile should make it highly attractive to operators

The system will drive high-efficiency, low-pressure fans, which “sport variable pitch for strong off-cruise performance, and feature regenerative braking to replace noisy spoilers. Meanwhile, 40% shorter runway requirements, 75% lower community noise, and highly responsive power without altitude lapse are key to door-to-door times.”

Quiet electric fans will have variable pitch rotors to allow “40 percent lower runway requirements, 75-percent lower community noise,” and “highly responsive power without altitude lapse.”

Development of this range of aircraft, which will eventually comprise 10-through-50-passenger machines, will put Boeing and its subsidiary in a largely uncontested market niche, serving 100 to 700-mile routes at 340-mile-per-hour cruising speeds.  The other Boeing niche market is more widely served, with Airbus and a variety of European and Chinese competitors vying for market share.

Acquiring a Specialist in Autonomous Flight, Innovation

In a joint press release, Aurora Flight Sciences and Boeing announced their hopes for a new melding of each company’s strengths.

“Manassas, VA, October 5, 2017 – Boeing [NYSE: BA] plans to acquire Aurora Flight Sciences Corporation, a world-class innovator, developer and manufacturer of advanced aerospace platforms under an agreement signed by the companies. Aurora specializes in autonomous systems technologies to enable advanced robotic aircraft for future aerospace applications and vehicles. ‘The combined strength and innovation of our teams will advance the development of autonomy for our commercial and military systems,’ said Greg Hyslop, chief technology officer and senior vice president of Boeing Engineering, Test & Technology. ‘Together, these talented teams will open new markets with transformational technologies.’”

Aurora has been developing an autonomous flight vehicle that would fulfill Uber’s plans for a flight-sharing service that would emulate the ride-sharing programs Uber provides for ground-bound commuters.  Their system, already demonstrated in quarter-scale model form, allows vertical takeoffs and landings, with the transition to horizontal flight aided by high-aspect-ratio wings to reduce energy consumption and allow swifter flight.  Aurora hopes to demonstrate full-scale flight in 2020, joining eHang and Volocopter in Dubai for Uber flights.

Opportunities abound in Aviation for exploring new ways to traverse the lower heavens.  Boeing is testing at least two of these and may help to bring about a revolution in short-range flight.


David Ullman: Flying on Multiple Tiny Motors

David Ullman, a professor emeritus at Oregon State University, predicted electric flight’s future in articles in 2009* and 2010**.  His predictions have come (mostly) true and David is working to fulfill the rest.  His background in mechanical and aeronautical engineering provides credibility for his prognostications, and he’s taking practical steps to take electric aviation to a next, very creative level.

While Uber’s Elevate Summit in Dallas earlier this year focused on big-money players in the vertical aviation world, David and co-creator Vincent H. Homer promoted their paper, “The IDEAL for Near-VTOL Aircraft.”  IDEAL represents “Integrated Distributed Electric – Augmented Lift” flight, using “thrust from distributed electric propulsion to improve the lift and drag performance of the aircraft during takeoff, cruise and landing.”  As their paper explains, VTOL flight requires power equal to 1.25 times the weight of the aircraft to ensure secure takeoffs and landings.  An IDEAL aircraft would require thrust equaling about one-third of the STOL craft’s weight to provide excellent performance.

It doesn’t look much like a four-seat Jabiru, but that’s the donor plane for the DW-1 – the realization of an IDEAL

Because so little relative power is necessary, the IDEAL aircraft would have greater range “using current batteries,” or would be able to reduce battery weight for the same range as that of a comparable VTOL craft.

The Ullman wind tunnel in his Independence, Oregon Hangar/garage.

Even better, though, the design can provide management of the lift distribution on the wing, and the 16 to 20 motors David proposes would provide a high level of reliability.  When he first saw the design concept last year, your editor was a bit skeptical, but having seen David’s large wind tunnel and well-defined testing techniques, that outlook has been replaced by the attitude that David and Vincent are on to something with great promise.

Similar but Different

Similar to NASA’s X-57 Maxwell, the DW-1 (real-world version of IDEAL) is a distributed thrust machine, with 16-to-20 small electric ducted fans spread across the front of the wing.  The X-57 has tractor (forward-facing) propellers, though, pushing air over the top and bottom surfaces of the wing.  DW-1’s propellers are housed in ducted fans blowing only over the top of the wing.

Electric ducted fans blow air over only the top of DW-1’s wing

According to the presentation on the DW-1, the redesigned wing has only 60 square feet compared to the original’s 100.5, and the aspect ratio goes from 9.8 to 15.  That would reduce the overall chord of the wing to about two feet, requiring a good low-Reynolds number airfoil, something accommodated by the Riblett 37 A6 18 used in initial wind-tunnel tests.

Maxwell visits future DW-1. Mary Maxwell takes in David Ullman’s explanation .about future for rebuilt Jabiru: red and green beard helped David direct traffic at fly-in that day


The Jabiru, which David is resuscitating from a wreck, has its six-cylinder Jabiru 3,300 cc engine in place for initial flight testing, which should take place soon.  After that, the new wing and distributed power system will take the old wing’s place, and the Jabiru will give way to a newly streamlined nose, which will also make the fuselage a lifting body.

16 or 20 Tiny Ducted Fans

David has selected an electric ducted fan that in the current design, will populate 16 places across the leading edge of the wing.  Each 50-millimeter (almost two-inch) diameter fan can produce 4.2 horsepower and nine pounds of thrust – 67.2 horsepower and 144 pounds of thrust total.   David notes that Airbus’s E-Fan’s two EDFs produced 86 horsepower peak.  At $375 each, the little powerhouses total $6,000 and weigh only 21 pounds total (including 11 pounds of 10 AWG wire).  Admit that it’s a bit noteworthy that the wiring weighs more than the motors.

16 of this two-inch diameter EDFs can produce 144 pounds of thrust

Besides the extremely redundant power system, the blowing adds to the lift coefficient for the wing.  A plain wing without flaps can take off at 51knots (58.65 mph), and the same wing with 10 degrees of flaps can leave the ground at 44 knots (50.6 mph).  30 degrees of split leading-edge flaps yields a 37 knot (42.55 mph) lift off, but David’s ducted wing drops that to 24 knots (27.6 mph) – ultralight speed.

Predicting Again

A great deal will depend on available batteries.  David keeps an optimistic outlook about that, the chart below detailing current realities and projected, realistic assessments of the near future.  He sees batteries as evolving rapidly, with an annual rate of improvement in energy density, for instance, of seven to eight percent.  Costs are dropping, making future costs even more of an incentive to go electric.  DW-1’s 16 motors cost $6,000, but compare that to a $17,000 Rotax 912, which weighs 171 pounds and consumes about $25 per hour in gasoline.

We’ll be following up on the DW-1.  David’s history as a designer, teacher, and President of EAA Chapter 292 shows that he can organize and carry out significant programs.  His progress on what last year was a basket-case Jabiru shows his practical capabilities.  This could be a contender at STOL events in the near future.

Book Review:  What Will Your Grandchildren See When They Look Up?

Amazon explains a book edited by David Ullman this way.

“This book explores the future of aviation. It was developed by students in a class titled “The History of Aviation 1800-2200” offered through the Honors College at Oregon State University. The course reviewed the history of atmospheric flight and, in parallel worked with the students to generate a vision of the future, specifically at a time when their grandchildren become aware of objects in the sky – about 2050. The students make predictions about the future of drones, autonomous flight, supersonic passenger flight, the use of new materials and other topics driving the evolution of aviation in the twenty-first century.”

Your editor read the first edition, and aside from a few quibbles (former English teacher, you know) found the work of the young people involved to be a great reflection on David’s teaching skills.  The second edition, quibble-free, is available for a modest price and is well worth the time of any forward-looking reader.

*“Hear the Hum? An electric airplane may be coming soon to an airport near you.” KITPLANES, November 2009, pp 15-19.

**“The Electric Powered Aircraft: Technical Challenges“, EAA Experimenter, May 2010.