Dropping a digit and its Latinate numeration, the recently renamed Sunseeker, a joint collaboration between Eric Raymond and a group of German, Swiss, Polish and Slovenian contributors, is showing progress towards its 2011 test flights. The 23-meter (75.46 feet) span solar-powered sailplane takes its wing from the Stuttgart Akaflieg Icare II, its fuselage from the Stemme basic profiles, is being built at least partially in Poland, and uses an electric motor designed by Slovenian native Roman Susnik, as noted in an earlier entry. The craft’s specifications provide evidence of the care employed in the design and construction of this lightweight marvel. A 75-foot wing aircraft weighing 270 kilograms (594 pounds) empty and 470 kilograms ( 1,034 pounds) when carrying two in its side-by-side cockpit is an achievement. Compare that to the 345 kg (765 pounds) empty weight and 550 kg (1,220 pounds) maximum weight of a “light” Piper Cub, with only a 36-foot, strut-braced wing. The 13.8 pounds-per-foot span loading (compare to the Cub’s 33.9 pounds-per …
Drs. Seeley and Moore Hit One Out of the Airpark
The January 2011 issue of Popular Mechanics resurrects the perennial hope for a flying automobile. The cover taunts, “(Go Ahead, Laugh) But NASA, DARPA & the FAA Are Serious.” Sharon Weinberger taunts some makers a bit in her article, “Driving on Air,” as she looks at a variety of Transformer-style vehicles that can travel by land or air with the fewest inconveniences. She notes the differences between propelling cars and planes, and looks at extremely different modes of giving people personal aerial transport, including the Moeller Skycar (“Inventor Paul Moeller has been developing the concept for nearly 50 years. To date, the M400X has only hovered on a tether.”), the Martin Jetpack, The Cartercopter, and the Terrafugia Transition that’s been getting an enormous press following (and a featured spot in the Hammacher Schlemmer Christmas catalog) lately. She ends with an overview of Dr. Mark Moore’s Puffin, detailed in this blog in January. After explaining that a commuter using the Puffin would rise …
Pipistrel’s Hybrid Cruiser
The Pipistrel folks in Slovenia have been producing some suprising aircraft with surprising names for the last two decades. Their Virus and Sinus motorgliders are well-traveled and well regarded, having won honors in the 2007 Centennial and 2008 General Aviation Technology Challenges sponsored by NASA and managed by the CAFE Foundation. The firm recently announced that it won the European Business Awards prize as the Most Innovative Company in Europe – out of 15,000 entrants. Indeed, their real-time posting of their solar-powered factory’s electrical output is a strong reminder of that drive to create new paths to the future. Another reminder of Pipistrel’s creative juices is the picture of their four-seat hybrid aircraft, which should be flying in the new year, according to Tine Tomazic, part of the company’s research and development team. Tine confirms that the aircraft will cruise on 160 horsepower at 200 knots (230.4 mph), is a hybrid – although not a parallel hybrid, and that its “performance will definitely …
Electric Waiex Makes First Hop
On Friday, December 3, Sonex Aircraft, LLC achieved a long-sought goal at Wittman Field, Oshkosh, Wisconsin, successfully flying their electric two-seater Waiex. Unveiling their craft at the 2007 AirVenture on the same field as part of their E-Flight Initiative, the team quietly and with some back-to-the-drawing-board resolve worked for the next three years to solve the many problems that confront any group reaching for that elusive next best thing. Evidence of this are the version numbers on the motor and controller as noted in Sonex CEO and General Manager Jeremy Monnet’s comment. “We have also already started our motor v4.0 design and motor controller v12.0 to be integrated on N270DC. Many more great things to come on this project!” Having seen Peter Buck’s video of early testing at the Experimental Soaring Association’s fall workshop in 2008, in which the controller self-immolated (later found to be the classic loose wire scenario) this writer was impressed with the openness of the presentation and the reminder that such developments are never as …
Not Your Father’s 172
George Bye, CEO of Bye Energy and head of the Green Flight Project, hopes to test fly the electric Cessna 172 in the spring of 2011. Recent illustrations show the “full-dress” electric craft with Ascent solar cells, a high-tech propeller, streamlined cowling, and vortex collectors at the wing tips’ trailing edges. Each element is intended to extend the range and efficiency of the airplane, a strong selling point, particularly in electrically-powered machines. Ascent Solar’s thin-film cells are thinner than a human hair, and thus will not impede the airflow over the wing’s surface. As the cells’ efficiency grows with development, they will provide greater flexibility of operation. Their resistance to failure, demonstrated in the video, will enhance the reliability of the overall airplane. George Bye has noted an economy of operation that might relight some aviation enthusiasts’ desire to go flying. Standard 172s cost about $35 to $50 per hour in direct operating costs, with those costs climbing as oil …
A Sweet Look Into the Future
Zach Hoisington, an engineer with Boeing Research and Development, proposes an electric airliner concept through the Subsonic Ultra Green Aircraft Research (SUGAR) program. During the CAFE Foundation’s fourth annual Electric Aircraft Symposium in Rohnert Park, California in April this year, he shared an amazing array of alternatives. Making airliners viable in an era of disappearing fossil fuel has caused NASA and aircraft producers to explore different design approaches, including joined wing aircraft, strut-braced wings, and hybrid wing-body configurations. Strategies for doing more with less may include aerial refueling for extended range flight with larger payloads, and formation flights on common routes like those of migrating birds to reduce induced drag. New sources of power may include hydrogen fuel cells and podded or integral batteries. Although the last option filled most of the talk, it came with the caveat that given current levels of battery development, it would take 5.5 million pounds of cells to produce the same energy derived from 60,200 pounds of …
Would You Believe There Are Two Electric Cri-Cri’s?
EADS, the Airbus people, gained a high degree of publicity with their four-motor Cri-Cri, as reported here previously, but a new contender has outraced it. Didier Esteyne flew the EADS plane for the press and showed it to good advantage. His mount was powered by four 15-horsepower electric motors, paired in pods on either side of the plane’s nose. The contra-rotating propellers gave a good performance judging from the in-flight video. EADS’ 60 total horsepower gave it a top speed of 141 miles per hour, but that was eclipsed by another electric Cri Cri, this one with a single 25-horsepower Electravia brushed motor on each stalk. Bigger motors swinging bigger propellers gave it a speed advantage and a world record of 262 kilometers per hour (162.44 miles per hour) , easily topping the Italian ENFICA-FC’s 135km/hr (83.7 mph) set earlier this year. Propellers were made by E-Helice, a part of Electravia, headed by Anne Lavrand, who also founded APAME, the French Association For the Promotion of Electric Aircraft. …
163 Horsepower from 25 Pounds
ThinGap, LLC is well known for small motors with excellent performance characteristics, eliminating the use of iron and its resultant “lossiness” and depending instead on copper foil, rather than wire windings for its internally clean structure. The design leads to a lack of “cogging,” that notched feeling found when turning over some motors by hand. Each individual magnet causes the rotor to stop, or “cog,” sometimes making low-speed operation a bit hesitant and smooth transitions difficult. That, the unique ring design and an aluminum housing help carry heat away and allow for an internal controller. ThinGap have focused on smaller unmanned aerial vehicle applications for many years, but have moved into larger automotive and aircraft products, with one model in particular capturing our attention. The non-production 14090 ring motor is 14 inches in diameter, weighs 25.6 pounds and can deliver 122 kilowatts (163 horsepower) – about 6.4 horsepower per pound and close to the Halbach array motors of Geoff Long …
The Verticopter® , an Adaptable and Expandable Convertiplane
Oliver Garrow, founder, designer, and President of Garrow Aircraft LLC, says it right up front, “My design is completely counterintuitive.” Pilots are used to counterintuitive thinking. Push the nose down and add power when you’ve stalled and are heading groundward anyway, for instance. But the logic of what Garrow is doing becomes apparent only when you see the Verticopter® flying. Adaptable for varying flight characteristics, the Verticopter can be powered by one or more motors. A single motor, for instance, would provide a simple solution for a conventional takeoff and landing (CTOL) aircraft. A short takeoff and vertical landing (STOVL) airplane might use two or more motors. Full vertical takeoff and landing (VTOL) would require four to six motors. Motors can be pivoted on all models, providing vectored thrust that makes the most of the airplane’s unique configuration. Garrow sees electric power as ideal for this application, and the use of one or multiple motors simplifies the problem of vectoring the …
Getting Wired on the e-Spyder
Stephan Boutenko of Alternair passed this along, and it is worth a read. Jason Paur of Wired Magazine’s Autopia web site reports on flying Tom Peghiny’s e-Spyder, a combination of Tom’s Flightstar ultralight with a Yuneec motor, controller and battery. Paur’s impressions are highly positive, with the desire to continue the experience. He notes, “Flying on battery power is about the unique experience of flying without the noise, vibration and smells of a traditional engine pulling you along. It’s an entirely different sensation. And like gliding, it is about the challenge of flying within the limitations of the aircraft and maximizing your time aloft. “’It’s like hypermiling a flight,’ Peghiny says.” Hypermiling in automobiles is the act of conserving fuel by tactics such as accelerating gently to a speed somewhat above the average desired, then coasting to a point below that average and accelerating again. Electric aircraft may require such tactics for at least the immediate future until battery technology …