Klaus Burkhard publishes a wonderful web site and blog on ultralight sailplanes, with special attention to the Banjo sailplane, one of which he owns and flies. His interest in other craft is broad, though, and he recently shared news of a flying wing sailplane that can be electrically powered. Its designer and builder, Dr. Andre’s Chavarria-Krauser explains: “Schneewittchen (Snow White) is designed to fulfill the requirements of LTF-L, a class of very light airplanes with up to 120 [kilograms] (264 pounds – 10 more than U. S. Part 103 limits) empty weight. The requirements are quiet stringent, including not only the extremely low empty weight, but also a very low stall speed below 55 km/h (corresponds to 30 [knots] or 34 MPH).” The stall speed is still six mph faster than Part 103 rules allow. Snow White’s all-wing configuration suits this class well, according to its builder. Its thick center section, which could be seen as a lifting-body layout, allows lighter spar weight …
Silent 2 Electro Certified in Germany
Luka Znidarsic shared this happy message this morning. “We are very proud to inform you, that the SILENT 2 Electro, equipped with our FES system, has been awarded Type Certification by the German Aero Club (DAeC). “This is the very first electric powered Ultralight sailplane certified, by DAeC. This represents a significant milestone in gliding history, which marks a new age of technology!” We hope this breakthrough in Germany encourages our own Federal Aviation Administration to review their schedule for electric aircraft certification. Such rule making would allow sales of existing electric motorgliders and light aircraft and encourage others to step up development of these alternatives to fuel-burning lightplanes. The Type Certificate gives some clear ideas of the technology incorporated in the very elegant little bird. The 13.2 meter-span airplane has a 22 kilowatt (peak power) motor and electronic speed controller of the Znardnic’s own design for instance. This motor can run at 20 kilowatts continually and swing a one-meter propeller at 4,500 …
The Archaeopteryx E
Two Swiss students, David Braig and Thomas Hewel at the ZHAW Zurich University of Applied Sciences, have adapted a pair of small electric motors to the Archaeopteryx ultralight hang glider. A Swiss, high-end product by Ruppert Composite GmbH Hittenberg, the motorless version has recently achieved a flight of 407 kilometers (252.3 miles) from a foot-launched start! Braig and Hewel, probably realizing that not all locales provide mountain peaks from which to hop off, developed a simple, detachable system to allow self-launching from flat terrain. The system has two carbon fiber wing “I-pods” that hold the motor, aluminum motor mounts and batteries, and an “E-box” in the cockpit, with cables connecting the elements. Total weight is 16.6 kilograms (36.52 pounds), which is a significant boost in the normal airplane empty weight of 54 kilos (118.8 pounds). One writer noted that the 100,000 Euro cost for the airplane meant a price over $1,000 per pound – high end indeed. You get what you pay …
Jerry Booker – A One Man CAFE Foundation
An engineer retired to southern Illinois farm country, Jerry Booker has designed and built several airplanes, his latest being the Red Tail Hawk, a Part 103-compliant self-launching ultralight sailplane. He has flown 15 times in his new creation, maintaining meticulous notes and downloading data for review by others. His empirical approach to testing the limits of his electric powerplant (a Randall Fisher 18 horsepower brushed motor/controller combination) and airframe represent a thorough and careful examination of a type of airplane that other homebuilders might be able to make with currently available systems. Jerry’s flight reports are dispassionate and carefully logged, following much of the approach and including many of the criteria developed over the years by the CAFE Foundation. He uses an EagleTree flight data recorder that was developed for model aircraft to track the ups, downs and other parameters of his flights. He checks his airspeed against an Etrex GPS. Jerry posts the results of each flight in the …
Ultralight and Electric – The Red Tail Hawk
Many of us dream of retiring and pursuing the dreams that sustained us during our careers. One man has done that with the kind of work ethic that makes retirement highly productive. He maintains two web sites; a Yahoo group dedicated to his latest homebuilt electric sailplane, and a more inclusive overview of his many aeronautical projects. Jerry Booker took early retirement from the architectural technology profession, and having grown up on a farm, “enjoyed ‘green’ living, with a lot of physical activity, and now [lives] in the farm country in central Illinois.” Designing and building even a simple airplane is a task that requires the willingness to learn and explore new ideas, and if that craft includes an electric powerplant, a willingness to experiment at a fairly high level. Jerry reports, “I always had an interest in research, design, and development, and am mostly self-educated from reading and trying things. “In addition to Alex Strojnik, I got a lot from the …