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 …
Solar Impulse – Swiss Pride
Andre’ Borschberg, CEO of the Solar Impulse project, has been flying the giant airplane over many scenic and civic sites in Switzerland, crossing from its home field at Payerne to Geneva International Airport on September 21, and then returning the same day to Payerne. The next day, Borschberg cruised to Zurich International Airport and returned to the plane’s home base. As quoted in the project’s press release, Borschberg was happy about the chance to view Switzerland from his rare and lofty perch. “’These flights are just amazing! Thanks to the plane’s low speed, I was able to discover Switzerland from a completely new angle, fully taking in the beauty of our country!’ said André Borschberg, CEO and Co-founder of Solar Impulse, from the cockpit of HB SIA in Zurich. ‘The Swiss solar flights represent a major step forward for our team, taking us away from our customary airspace. We have learned to work together with international airports, merging in with …
Solar Sailer Seeks Companionship
Until now, all solar flight has been solo. This is understandable, given the need for light weight and large wing areas. But Eric Raymond is about to change this with Sunseeker III, the world’s first two-seat solar-powered airplane, shown at last weekend’s Green Aviation Show at Le Bourget Field near Paris, France. Indoor displays were in the Musee’ de l’Air et de L’Espace (the Air and Space Museum). Sunseeker III has a roomy side-by-side seating arrangement in a fuselage derived from the Stemme sailplane. The wing is crafted from the molds (on long-term loan) for Stuttgart University’s 25-meter (80 feet) Icare II, flown in 1996. As Raymond explains in his blog, “Professor Nitschmann’s design firm www.sfl-gmbh.de is very friendly to our project, and we hope to work together in the future on solar powered aircraft.” The 20 kilowatt motor is being developed by Slovenian Roman Susnik, and fabrication of the wings is taking place in Slovenia, making the effort a virtual European Union assemblage. In his blog, Raymond …
Many Happy Hours in Sunny Skies
Eric Raymond, over the last 20 years, has accumulated more solar-powered flying hours than any other pilot. And what hours these have been. Having met Gunther Rochelt and flown Rochelt’s Musculair human-powered airplane in 1986, Eric was inspired to apply the light construction techniques to the building of a solar-powered airplane. In 1990, he flew Sunseeker I across the United State in 21 hops totaling 121 hours in the air, going from California to Kitty Hawk, North Carolina, the birthplace of powered flight. He upgraded Sunseeker over the years, improving the powerplant and aerodynamics of the amazingly light aircraft. Even with solar cells, batteries, and a 2.5 kW motor, the airplane weighed little more than a legal ultralight. Sunseeker II came to have a new wing, a motor twice as powerful as that on Sunseeker I, and improved battery and solar panel controls designed by Alan Cocconi. Eric made several flights in the new craft, one from Ramona, California to …