Only seven months after the Green Flight Challenge, this year’s CAFE Foundation Electric Aircraft Symposium had a stellar lineup of presenters, some hopeful signs of progress in battery development and some challenging new visions that will apply in the kit aircraft world.
JoeBen Bevirt, manufacturer of motors that Patrick McLaughlin describes as “the best,” chats with Tine Tomazic, designer for Pipistrel Aircraft.
Santa Rosa, California, is Wine Country central, with abundant sunshine, nearby geysers generating electricity and a lively and supportive interest in aviation. Close to Silicon Valley, the University of California at Berkeley, Stanford University and other centers of research and learning, the symposium draws on local resources. Couple those learned presenters with experts willing to travel from Europe and Asia to be part of the program or the audience and you have a world-class gathering. The smart crowd is betting on some exciting developments this year. Highlights included new battery chemistries including IBM’s lithium-air 500-mile project; the F-22 designer’s 300+ mph electric homebuilt; a kitbuilt, five-seat, high-performance hybrid; and the FAA’s planned regulations to regulate electric Light Sport Aircraft. Supporting that, Ron Gremban of ForSites Corporation, who developed the first plug-in Prius, suggested forming a non-binding industry consortium to promote electric-aircraft safety.
Jack Langelaan, team leader, and Tine Tomazic, designer of the Pipistrel G4, told how they built and flew the GFC winner.
Bill Dube and Eva Hakansson (second and third from right) display the Killajoule electric motorcycle with sidecar. It has gone 151 mph and will go faster soon.
Taking Winona for a Winged Mercy Trip
Brien Seeley, founder and president of the CAFE Foundation, had a Wobegone presentation (as in Lake Wobegone) to set the tone and agenda. Taking his cue from Garrison Keillor’s popular stories about the mythical town, Seeley told of Winona, who, in a 2021 update, needs to visit her sick sister Lena in Lincoln, Nebraska. Airlines don’t serve her town, buses are irregular and expensive, and Winona is beside herself. Then she sees an ad for the Anytime Ford Sky Pony, an electric-aircraft taxi alternative. It costs only 10 cents a mile, and she ends up sharing the ride and expenses with a fellow traveler. The airplane’s triple-redundant GPS and auto-landing capabilities allow it to fly into Peter Pan Airpark, near Winona’s home.
After a 90-foot ground roll and a steep, nearly silent climb, Winona is heading toward Lincoln, where she is eventually reunited with her sister.
Seeley emphasized that the scenario is doable with today’s technology, and it takes only the will to make it real. He also promoted quiet propellers to help neighborhood airports be good neighbors.
Jack Langelaan (second from left), Pipistrel G4 GFC team leader, makes a point with Tom Gunnarson of the FAA and Mark Moore of NASA.
Cell Meetings
Three battery presentations promoted different technical approaches; all promised greater range and power for electric vehicles. First, Cary Hayner from Northwestern University spoke on “Engineered Graphene Electrodes for Lithium Batteries,” explaining how wrapping electrodes with atom-thick graphene can help increase energy density in batteries. Using half-cells with a known electrode on the cathode and experimental electrode on the anode, researchers can test variables and determine best combinations of ingredients. Hayner and his researchers poke 20-nanometer holes in the atom-thick material to make “holey graphene,” which diffuses ions more efficiently and increases energy density 60%—and up to 130% with a nickel magnesium cobalt (NMC) cathode. At least experimentally, Hayner has produced a 600-watt-hour-per-kilogram cell and a graphene “paper” that might allow it to be manufactured more easily.
The happiest couple at the event, Dube and Hakansson gave a synchronized presentation spilling over with good spirits and astonishing information on the Killacycle and other projects.
Bruce Katz from PolyPlus Battery Company brought back his water-immersed battery, which, in seawater, can provide nearly 1000 hours of energy—ideal for underwater Seal teams. For aerial transport, his batteries use LISICON (lithium super-ionic conductors) and NASICON (sodium super-ionic conductors), solid electrolytes to seal the electrodes and give an energy boost, which, with lithium-sulfur chemistry, could be five times greater than current lithium-ion cells. Time Magazine chose Katz’s creation as one of the 50 best inventions of 2011.
Winfried W. Wilcke is the senior manager of Nanoscale Science and Technology at IBM’s Almaden, California, research center. He founded and still heads the Battery 500 Project, which, with several industry and academic partners, has the goal of creating a 500-mile battery for electric vehicles. He said that if all cars in the U.S. were electric, 73% of them could be charged at night with the excess energy in the existing power-supply grid.
In a typical week for a car driven by the 500-mile battery, a 4-kilowatt home charger, used five nights during that week, would provide all the energy necessary for the week’s travels, and “range anxiety” would be eliminated.
The Volta Volaré’s roomy cockpit includes room for full IFR instrumentation.
His lithium-air battery could give five times the energy storage of a lithium-ion battery. IBM’s goal is to achieve 1000 watt-hours per kilogram in cells, with the theory showing this could go as high as an astonishing 6000 wh/kg.
He ended his talk with the unsurprising but sobering news that batteries are not yet anywhere near the energy density of fossil fuels. Filling his Beech King Air with 384 gallons of Jet A (2575 pounds) would only be matched by 6233 pounds of 1200-wh/kg batteries, leaving no ability to fly at all.
The Volaré can land and take off in 1500 feet, allowing use of various airports.
With worldwide energy demands doubling every 15 years and a current lithium-ion battery market of $8 billion (projected to be $30 billion by 2017), the impetus to bring high-performance, high-quality batteries to market becomes readily apparent.
At a more “practical” level, Bill Dube and Eva Hakansson shared their secrets for wiring high-powered battery packs that take world records in motorcycles, and perhaps soon in Le Mans racers. The couple talked about building and racing Killacycle, a 500-hp two-wheeler that catapults Dube from 0 to 60 mph in less than 1 second and until 2010 was the undisputed electric drag-racing champion. Hakansson is campaigning Killajoule, an exotic sidecar racer in which she hopes to top 400 mph on the Bonneville salt flats—and she’s already done 151 mph in a machine that her husband describes as “an electric drill motor with a big battery pack.”
Patrick McLaughlin of Mountain High Oxygen discussed his promising motor controller, which can command any type of electric motor, and proposed an open-source organization to develop and promote the design.
Carlo Treves showed FlexSolar panels that could be wrapped around an aircraft’s surface to allow electric recharging of an e-plane’s batteries while it’s parked.
Charging Ahead
Two Pauls caught attendees’ attention with high-speed approaches to electric flight. Paul Schlein, retired chief scientist on the Lockheed F-22 Raptor, has been getting scientific in his garage, designing and building a streamlined 4-foot diameter fuselage, inspired by Bruce Carmichael’s teaching and derived from revolving a NACA 66-series airfoil. Extremely small Hershey-bar wings would carry 33 pounds per square foot, and an inverted V-tail, attributed to Molt Taylor, would slope away from interference drag. Now testing a small-block Chevrolet V-8, he looks forward to powering his two-seater with electricity.
The structure for this projectile will weigh around 230 pounds, with propulsion system adding another 800, and 150 pounds of ice water chilling the motor and batteries, possibly by melting through skin-mounted radiators, a la the Schneider Cup racing seaplanes of the 1930s. Cooling drag will be zero, with a fuselage drag coefficient at a phenomenal 0.02. He hopes to achieve 700 kph (434 mph) with low trim drag, high stability and little thought for stall speed—but great concern for stall behavior.
Less extreme, but extremely attractive, Paul Peterson’s Volta Volaré GT4 is a four-seat (five with optional rear-bench seating) canard, hybrid electric craft that can cruise 210 knots (240 mph) on just over 7 gph. Peterson plans later versions that will be all electric, and one variant will be a twin-motor, six-seat, high-altitude business craft competitive with much more expensive turboprops at a much lower fuel burn—essentially zero fuel burn when the all-electric version is introduced with virtually maintenance-free motors.
With a builder assistance center in Sebastian, Florida, and a “skunk works” type hybrid and electric-power-system development program underway in Hillsboro, Oregon, Peterson’s ambitious undertaking is drawing worldwide attention and orders. It will be interesting to see how the Volaré compares to Pipistrel’s Panthera, another high-performance hybrid.
Peterson also plans a ViVolaré Familia (Green Flying Lifestyle Club), a limousine-type usage plan in which members would fly with a professional pilot. There’s more than just aerodynamic or power-train innovation at work here.
A dazzling image in flight, the Volaré shows off its twin vertical stabilizers.
Smaller, Lighter Hopefuls
Gene Sheehan’s motorcycle and aerodynamic expertise once produced a streamliner shell with a drag equivalent frontal area of 0.1317 square feet, about the size of a small sticky note.
The all-new e-Quickie has achieved similarly remarkable figures, both for development and performance. Sheehan and his crew crafted 41 carbon-covered molds from leftover 11-ounce-per-square-yard carbon fiber—too heavy for flight, but just right for molds. CNC-routed blocks of foam provided the forms, and the carbon fiber provided the rigidity. All parts on the airframe are a carbon-foam-carbon sandwich, with the exception of the vertical tail, made from Kevlar to allow radio waves to escape and get through to the antennas hidden within. Resin was minimized through one-step molding, and pre-manufactured model-aircraft carbon strips created a 2-inch wide, 1/15-inch-thick spar cap on the canard. (For more on Sheehan, see “Mojave.”)
A new version of a proven German brushed permanent magnet motor, which Sheehan claims is as efficient as a brushless, provides motive power, with an Alltrax controller from golf carts throttling through a slider potentiometer normally used on electric guitars. One of two battery packs is run through the controller to allow takeoffs and landings, while the other is wired straight to the motor for cruise. Sheehan cautions that changing phase when changing motor speed can cause fires because of electrical noise.
Stephan Boutenko of Alternair presented details of his two-seat electric Light Sport Aircraft now under development. The Alternair Amp-100 is designed to fight the expense of internal-combustion-powered airplanes with 2.5 hours of endurance and a 200-mile range possible on its 29-kWh, all-aluminum-encased battery pack. This is calculated, based on 2009 batteries, to allow flying to a nearby airport and returning home on one charge, with a 30-minute reserve.
With an empty weight of 880 pounds with batteries and useful load of 440 pounds, the Amp-100 fits neatly into the LSA market. Its 35-kW (47-hp) LaunchPoint motor will make it a good neighbor, with a 65-dBa maximum noise output. The prop limit is 1600 rpm, and 1400 rpm makes for quiet cruising. Wireless access will allow the iPad generation to check the health of the plane’s advanced electronics. A BRS rescue parachute and five-year limited warranty should provide a sense of security. Boutenko says first deliveries will take place in 2014.
Seriously Now?
Tom Gunnarson from the FAA and Ronald Gremban from ForSites Corporation had similar goals and different approaches to making electric flight a safe experience in both LSA and Part 23 aircraft.
Gunnarson discussed assessing emerging technology, taking a risk-based approach and considering public safety to develop regulations that will apply first in the Experimental category, then LSA and finally for Part 23.
As electric aircraft garner increased public attention, there will be added concern. An audible sigh was heard through the meeting room when he announced that new regulations could be feasible in five to 10 years, but that new rules would seek to reduce fatal accidents and certification costs by 50%. He ended by promising the FAA could fast-track these with public encouragement.
Gremban talked about new safety concerns for electric aircraft and proposed an industry consortium to help develop operating protocols and standards.
For more information, visit the CAFE Foundation’s blog at www.blog.cafefoundation.org.
Dean Sigler has been a technical writer for 30 years, with a liberal arts background and a Master’s degree in education. He writes the CAFE Foundation blog and has spoken at the last two Electric Aircraft Symposia and at two Experimental Soaring Association workshops. Part of the Perlan Project, he is a private pilot, and hopes to get a sailplane rating soon.
