Unhappily, we missed seeing Tom Leite at this year’s Electric Aircraft Symposium. Happily, he was at Eurosport Aircraft, his company in Portugal, working on innovative new approaches to making electric and hybrid motor-gliding a reality. He also has a speedster that would give those who desire rapid transit a high-style alternative. As shown in the video from Aero Friedrichshafen, the Crossover will probably trend toward a simpler wing configuration, with a fixed span of 18 meters (59 feet) and flaperons that will replace the multiple flaps on the current short-span version being flown in test flights. It’s uncertain whether the current twin-motors that pop out of the sides of the extremely slender fuselage will be retained, but a new version of the Crossover will feature three power options. As shown at Aero 2014, the airplane has the two options outlined on opposite sides of the fuselage – the port side displaying the Rotax-powered version, with a carbon-fiber shaft transmitting power …
EAS VIII – A Day and a Half You’ll Never Forget
Who would pass up a chance to stay at a nice resort, attend lectures that challenge and inspire, and meet at poolside with speakers who bring some of the sharpest minds in the world to bear on some of the biggest problems we all face? Let’s face it. Global warming probably won’t be going away anytime soon, and aviation seems destined to play a bigger part in polluting our otherwise near-perfect atmosphere. Unless…we learn how to make our favorite activity (in the top five for most of us, anyway), into a more responsible way to travel and recreate. Since solving the problems which go with that responsibility will involve the best in aerodynamics, power systems and new, efficient technology, the CAFE Foundation has invited experts in these fields with demonstrated successes in meeting such challenges. To be held April 25 and 26, 2014 at the Flamingo Resort in Santa Rosa, California, the event will host speakers on everything from practical, …
Airliners Get Better Mileage than Cars, and Trains do Even Better
Airliners beat cars in fuel economy, especially on longer trips. That would not be news to attendees at recent Electric Aircraft Symposia, where speakers like Ilan Kroo, Stanford University professor and aircraft designer, have brought that message home. One of Kroo’s slides, shown below in a 2009 lecture (It’s nearly an hour, but worth a look and listen), lists a “narrow-body” airliner (in this case a Boeing 737-800) as able to fly one passenger coast-to-coast on 29 gallons of fuel, at about 81 passenger miles per gallon. A person carpooling his or her four-passenger Prius and driving responsibly could beat that (although not in the five hours required for the jet to make the total flight), but most trips are solo affairs, especially during commutes. Not anywhere near Green Flight Challenge efficiencies (403.5 ppmg for the winning Pipistrel G-4), such economies are improving with more modern versions of fuel efficient airliners. Cars are also gaining in fuel economy, prompted by government …
Batteries That Heal Themselves
Alert reader Colin Rush provided this breaking development in battery science. Regular readers will remember Dr. Yi Cui’s name. He’s a Stanford University scientist who has worked with paper batteries, much more powerful electrodes, and means of helping batteries stay together under the continuous strain of expanding and contracting during charging and discharging. He explained that at the third annual Electric Aircraft Symposium at the Hiller Aviation Museum, and has since adopted several tactics to overcome that problem. One commercial outgrowth of his work, Amprius, is working on commercial production that benefits from his insights. Since that internal flexing eventually leads to cracking of electrodes, Dr. Cui’s latest announcement brings some hope that such things can not only be overcome, but literally healed. Just as our bodies have internal resources to fight diseases and repair muscle and bone, batteries can be made to be self-healing. Dr. Cui has been a proponent of using silicon as a major component in electrodes, …
Dr. Seeley at AirVenture 2013
Imagine being able to walk one morning from your front door to a nearby small airport, step into an electrically-powered small airplane, point to a destination on an illuminated map on the airplane’s display screen, and be whisked to your destination so quietly that your passage overhead will not wake your neighbors. This is part of the dream that Dr. Brien Seeley, founder and President of the CAFE Foundation, presented to an appreciable and appreciative crowd on Friday, August 2 at the Rotax Pavilion during the Experimental Aircraft Association’s AirVenture 2013. His talk, “The CAFE Foundation’s Green Flight Challenge Program: Toward a New Transportation Mode,” was a roadmap to how the CAFE Foundation, NASA and corporate sponsors will present five new challenges leading to the type of electric short or vertical-takeoff and landing airplane that will enable neighborhood pocket airports. He also challenged EAA members to become involved, using their technical knowledge and talents to further the development of quiet, …
Ultra High Lift Without Flaps
Dr. Gecheng Zha, an Associate Professor with the University of Miami has an impressive set of credentials, culminating in a Ph.D.from the University of Montreal, Ecole Polytechnique. That, and his impressive body of work helped impress the audience at the seventh annual Electric Aircraft Symposium this last April. His work over the last decade has focused on generating high lift and low drag through circulation control on wings – even leading to the concept that wings can generate thrust instead of drag. This integration of aerodynamic forces would lead to highly efficient aircraft capable of flying on little – or even no power. Earlier attempts to increase lift and decrease drag have relied on sometimes complex, multiply flapped and slotted wings which require powerful mechanical actuators to work their magic. Others have used rotating cylinders laid spanwise on wing leading and trailing edges, or active suction or blowing to achieve their goals. Zha has looked at these and other …
A Milestone on the Road to Dr. Cui’s 10X Battery
Seeing the Amprius web site, one would never know that some “dramatic improvements” promised in the terse announcement might mean so much in terms of true breakthroughs. Neatly centered, Amprius’ total web site is a few lines of discrete text. Amprius is a leading Lithium-Ion battery developer Amprius’s silicon technology was originally developed at Stanford University and enables dramatic improvements in the energy density and specific energy of Lithium-Ion batteries. Amprius is backed by some of the world’s leading investors, including Trident Capital, VantagePoint Venture Partners, IPV Capital, Kleiner Perkins Caufield & Byers, and Dr. Eric Schmidt. Amprius, Inc., 225 Humboldt Ct. Sunnyvale, CA 94089 But the battery manufacturer has two first-generation product offerings with volumetric energy densities of 580 Watt-hours and 600 Watt-hours per liter. Most lithium batteries fall into a range from 250-500 Wh/l., putting the new cells at the upper limit of such batteries. Both Amprius batteries are now in production and available to original equipment manufacturers, …
Avoiding Propeller Strikes on Electric Aircraft
At last year’s Electric Aircraft Symposium, Ron Gremban, developer of the Prius plug-in hybrid, shared several questions about promoting safety in electric aircraft. One aspect that provoked deep thought was that of safety for those working around an electric airplane, whose propeller could start quietly and possibly strike an unaware bystander. During the Green Flight Challenge, it was noteworthy that unlike their gasoline-powered counterparts which idled while awaiting takeoff, the Pipistrel G4 and e-Genius awaited their turn to launch with propellers at rest, only spinning when commanded – and very quietly at that. The question of avoiding prop strikes found at least one answer at EAS VII. Karl Kaser demonstrated, in model form, his ePropeller Safety Device (eSD), noting “the risk to people, animals or objects in the propeller disk area and that they can be injured or damaged accidentally during the run-up of the propeller.” He first noted that issue in the case of e-Genius, on which he was …
Flying e-Genius for Two Years
At this year’s Electric Aircraft Symposium, Rudolf Voit Nitschmann, Len Schumann, and Ingmar Geiss shared their well-documented experiences with e-Genius, second place winner in 2011’s Green Flight Challenge. Flown by Erik Raymond and Klauss Ohlmann, the airplane managed 397.5 passenger miles per gallon on its 200-mile trek around a closed circuit between Santa Rosa, California and the distant geothermal power plants that provided the electricity for its flight. As Voit Nitschmann, leader of the e-Genius team since 2005 noted, one must design electric aircraft around the beneficial aspects of such vehicles to gain the greatest performance. Originally slated to be hydrogen powered, e-Genius mounts its 59-pound motor on the leading edge of the vertical rudder, more difficult with a heavier internal-combustion engine. This permits ample propeller clearance, provides blade protection and allows a short, retractable landing gear that is light and simple. With no turbulent flow over the nose, the cockpit can be streamlined like that of a sailplane and …
Pipistrel Shares Three New Products and Springs a Surprise
Slovenia, a tiny country which can be seen in its entirety from a light airplane, makes an astonishing array of such vehicles at the Pipistrel factory, awarded a European Union prize as the epitome of green manufacturing facilities. The company uses solar energy to power its operation and reports the number of kilowatts flowing through its plant on its web site. Naturally, we’d expect an environmentally responsible firm to build environmentally responsible products, and Pipistrel is committed to going green. Dr. Gregor Veble, Head of Research in the Research and Development Department; and Tine Tomažič, researcher and designer, shared a multiplicity of new products and gave an all-too-brief glimpse of a surprising future project with participants at the seventh annual Electric Aircraft Symposium at Santa Rosa, California. With over 300 of their two-seat Sinus and Virus aircraft in service, and 50 Taurus G-2 recreational motor gliders surfing the high mountain waves, Pipistrel has a growing customer base, and seems to …