Two Battery Fires in Self-Launching Sailplanes

Dean Sigler Batteries, Sustainable Aviation Leave a Comment

Klaus Burhard publishes a wonderful news and blog site promoting ultralight sailplanes.  His German site has been the source for many blog entries by yours truly, and the latest items from Klaus are of concern to anyone involved with electric aircraft. He has reported in the last week on a disturbing incident with a UK-based HPH glass-wing 304eS/Shark FES “self-starter,” or self-launching sailplane.  The airplane is a standard-class 15 meter (49.2 feet) wingspan plane.  As seen in the video below, The FES (Front Electric Sustainer) motor on the nose swings a propeller which folds into the front contours of the sailplane when not powering the plane.  When a pilot engages power, the rotation of the motor pushes the propeller blades out into the airstream. Two battery packs engineered by FES nest in a compact area behind the pilot.  Each pack contains 28 high-power Kokam lithium-polymer batteries of 43 Amp-hours each wired in series to give 2.1 kilowatt-hours of energy.  Packs …

From Ultralight Sailplanes to a Miniatur-Wunderland

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Your editor has several friends who lay claim to the appellation, “ferroequinologist,” (student of the iron horse), meaning they fancy miniature trains and the layouts that support them.  One friend helped construct a layout that takes up most of a good-sized building in Portland, Oregon – but even he would be dumbfounded by the massive installation in Hamburg, Germany – which includes an international airport in its midst that accounts for 180 takeoffs and landings per day and handles 1.2 million “passengers” per year. Blogmeister Klaus Burkhard oversees a wonderful web site based primarily on ultralight sailplanes.  His writings have alerted your editor to the twin-motor self-launching ultralight Holliday Obrecht and his compatriots are building at EAA Chapter 309 in Charlotte, North Carolina; Snow White, an electrically-powered flying wing inspired by the Horton Brothers, and produced an expansive entry on the Volocopter that included detailed photographs and specifications. A recent entry on Hamburg’s Miniatur-Wunderland told of the remarkable airport that …

Snow White – an Electric Flying Wing or a Lifting Body?

Dean Sigler Electric Aircraft Components, Electric Aircraft Materials, Electric Powerplants, Sustainable Aviation 2 Comments

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 …

Klaus Burkhard and the Archaeopteryx

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Klaus Burkhard is a sailplane pilot exploiting the air currents over his native Germany in 120-kilogram (264-pound) ultralight machines (most of which weigh far less) – which may become a part of an increasingly electrified sport.  He wrote this to your editor in response to recent coverage of the electric version of a record-setting ultralight sailplane. “I just came over your interesting website, reading your blog about the Swiss Archaeopteryx, where you described the Archaeopteryx as a high-end hang-glider, publishing a picture from an older version in ‘open’ variety. “Of course the Archaeopteryx is classified as hang-glider in the OLC (on-line competition)  and also as Class-2 hang-glider within FAI-regulations, as it´s foot-launchable and foot-landable as well, both basic requirements for FAI Class-2. “Since the Archaeopteryx is -contrary to normal hang-gliders- three-axis aerodynamically controlled by elevator, rudder and flaperons, it´s an Ultralight-Glider of the best with fantastic flying-abilities, outstanding flying-performance and uncritical in any situation. L/D is 29 in race-covering. “In 2012 …