{"id":8456,"date":"2013-11-21T22:19:45","date_gmt":"2013-11-22T05:19:45","guid":{"rendered":"http:\/\/cafe.foundation\/blog\/?p=8456"},"modified":"2013-11-21T22:19:45","modified_gmt":"2013-11-22T05:19:45","slug":"if-you-have-to-ask","status":"publish","type":"post","link":"http:\/\/cafe.foundation\/blog\/if-you-have-to-ask\/","title":{"rendered":"If You Have to Ask\u2026"},"content":{"rendered":"

Binder Flugmotoren- & Flugzeugbau is a German firm specializing in high-end single and two-seat motorized sailplanes which offer outstanding performance.\u00a0 Their EB29d Elektro<\/a> is a two-seater with winning lines and ways \u2013 as evidenced by their recent victories in European and American soaring contests.<\/p>\n

\"Open-class<\/a>

Open-class wings up to 28.3 meters give Binder EB29d Elektro high-class performance<\/p><\/div>\n

A self-launcher more intended for climbing and soaring than cross-country touring under power, the airplane shares some characteristics of operation and design with Lange\u2019s Antares and Arcus series and some ASH models.\u00a0 The motor extends and retracts on a long stalk, for instance, and the batteries for power are contained in the wings.<\/p>\n

Binder\u2019s EB28 and EB29 segelflugzeuge<\/i> come in 25.3 meter (82.98 feet), 28.3 meter (92.82 feet), and 29.3 meter (96.10 feet) spans, easily reduced or extended with a set of exchangeable wingtips.\u00a0 Binder\u2019s claim that \u201cNow you can choose the optimum wing span for every weather, in order to fly at the front of the competition or to enjoy great pleasure of flight.\u00a0This concept has been demonstrated by Michael Sommer winning the 2011 German open class championships.\u201d\u00a0 He also won the 2013 German open class and took second place in the 2012 World Gliding Championships in Uvalde, Texas with that ship.<\/p>\n

\"Emrax<\/a>

Emrax motor’s small size visually contradicts its 72 hp output<\/p><\/div>\n

Aerodynamically, the gasoline-powered and electric ships fly much the same after the retractable motor is tucked away in the long, slender tail boom.\u00a0 The Elektro<\/i> mounts a liquid-cooled Emrax motor of 53 kilowatts (72 horsepower) driving a Binder-designed, 1.6 meter- (5.35 feet-) diameter propeller which enables a climb rate of 3 meters per second, or 590 feet per minute.\u00a0 The batteries can loft the airplane to 3,500 or 4,000 meters, (11,480 or 13,120 feet), probably depending on wingtip selection. Once aloft, the two longest wing spans allow a lift-to-drag ratio of 63:1 or 66:1 and a low, but unspecified rate of sink.<\/p>\n

One set of batteries supplies energy to the motor and a second to the avionics and motor controller.\u00a0 The first consists of several strings of Panasonic lithium-ion cells giving 400 Volts, 72 Amps and storing 25 kilowatt-hours of energy, while the second is a Sony lithium-manganese, 14.4 Volt, 56-Amp-hour pack contained in the fuselage.<\/p>\n

\"Panasonic<\/a>

Panasonic Li-ion batteries have flexible connectors to follow bending within eight-piece wings<\/p><\/div>\n

This massive ship weighs 900 kilograms (1980 pounds) with two on board, battery packs and all, and its long wings flex noticeably in flight.\u00a0 With a maximum wing loading for the 25.3 meter ship of 58.5 kilograms per square meter (11.98 pounds per square foot) and for the 28.3 meter EB29 of 54.5 kg\/m2<\/sup> (11.16 lbs.\/ft2<\/sup>), it is definitely a high-speed, high-performance machine, evidenced by Binder billing the airplane as their \u201cracing two-seater.\u201d\u00a0 The EB29, regardless of wing span, is listed as having a maximum speed of 280 kilometers per hour (173.6 mph), fast enough for most powered lightplanes.\u00a0 Because of its clean lines, the airplane has a maximum cruising speed of 160 km\/hr (99.2 mph), using much less than the Emrax motor\u2019s 40 kW (53 hp) continuous power rating.<\/p>\n

\"The<\/a>

The EB29d Elektro’s cockpit reflects the airplane’s high performance capabilities<\/p><\/div>\n

For those seeking an electric self-launching sailplane with contest-winning performance, Germany offers a large number of choices, with the Binder being a top contender.<\/p>\n