Two electric sailplanes come from different ends of the soaring spectrum and each shows its own unique character. Their differences are as noteworthy as their geographic separation. Birdy Birdy is a single-seat, electrically powered motor glider that fits the European Union 120 kilogram class. The 264-pound empty weight puts it 10 pounds above America’s FAA Part 103 254-pound limit. But Euro craft in that category are not as limited in top or cruise speed. Birdy’s light weight required clever arrangement of components to enable a maximum takeoff weight of 280 kilograms (616 pounds) and pilots up to 1.95 meters (6’ 5”) tall. Its 13.5-meter (44.29-foot) wingspan carries only 13.9 pounds per foot, enabling 40:1 glide ratio at around 90 kilometers per hour (55.8 mph). Its 8.3 square meter (89.3 square foot) wing area lifts only 6.89 pounds per square foot, enabling a 63 km/hr (39 mph) stall speed with flaps. Birdy can top out at 180 km/hr (111.6 mph), well …
Project ATOS Wing Explores Ultralight Electric Soaring
Its translucent wing shimmering on the wall above Hall A7 at Friedrichshafen’s 2018 Aero Expo, A-I-R’s ATOS Wing commanded the attention of show goers. A-I-R (Aeronautic Innovation Rühle & Co GmbH) produces a line of ultralight hang gliders and electrically-powered craft based on a common wing design modified for different weight and performance requirements. Note the large wing at about 35 seconds into this perambulation around Hall A7, along with tantalizing glimpses of the other displays that we will cover in the near future. Although ethereal in appearance, ATOS wings can carry significant loads compared to their minimal weight. The 50 kilogram (110 pound) VRS 280, for instance, can carry an all-up weight of 330 kilograms (726 pounds), an impressive structural weight to gross weight ratio. Coupled with the Wing’s 28:1 claimed glide ratio and 0.55 meters per second (108.3 feet per minute) rate of sink, the Wing will allow long, lazy glides from altitude and even permit modest cross-country …