OSTIV Prize awarded to Stefan Gehrmann, Axel Lange and Luka Žnidaršič

for their outstanding contributions to the development of electric propulsion systems for sailplanes at XXXIII OSTIV Congress in Benalla, Australia.

For glider pilots and sailplane designers alike, the dream always was to increase the possibilities of motor-less flight by adding a silent, reliable and emission-free propulsion system. Despite early beginnings and first trials to install electric motors and batteries in powered sailplanes it was three people who have forwarded the idea of an electrically powered motor-glider into the reality,  which it has become today.

In 1992 Stefan Gehrmann started studies on electric propulsion systems and found that the new ultra-light sailplane Silent could be a suitable basis for such an electric motor-glider. In 1997 this concept was first flown under the AE-1 designation. After type certification in 1999 under national micro-light regulation the AE-1 became the first serial-produced electric powered sailplane available to the public. Stefan Gehrmann and his company have remained in the business to the present day, developing and producing electric components for different products and projects, with Solar Impulse probably being the largest example. Stefan Gehrmann therefore is honored for making electric propulsion available to customers with his AE-1.

Axel Lange started his path toward electrically powered sailplanes as an engineer in the Glaser-Dirks sailplane company. It soon became obvious to him that electric propulsion would be a suitable alternative to using combustion engines. Axel Lange took his chance to start a new business based on his ideas about electric systems. After founding Lange Flugzeugbau, he developed the Antares 20E as his first own product, combining a completely new electric propulsion system with other state-of-the-art elements like modern structures, excellent crash-worthiness and optimized aerodynamics. It took several years to complete type certification for the Antares 20E in 2006. Today this sailplane has become a familiar sight at glider airfields with more than 60 examples produced. The propulsion system now has also been installed into the Arcus E sailplane from Schempp-Hirth Flugzeugbau, making this the first two-seated electrically powered sailplane available on the market. Therefore, Axel Lange is honored for type-certifying an electrically powered sailplane according to sailplane standards and for opening up serial production of such a system.

Luka Žnidaršič was also fascinated about the possibilities of electric propulsion, being an excellent sailplane pilot and working in his company with electric drives and generators. However, he aimed for a much smaller and more affordable system than those available on the market. By developing a compact electric motor, which fits into the nose of a typical sailplane, and combining this with propeller blades folding to the sides of the cockpit, he created a simple and error-proof propulsion system for a self-sustainer in 2009. He called this system Front Electric Sustainer and under the acronym FES this system is now integrated into several sailplanes produced by different manufacturers. At the time of presenting this award, models of sailplanes from JSC Sportinė Aviacija IR KO (LAK-17B FES), Alisport (Silent FES), Schempp-Hirth Flugzeugbau (Ventus-2cxaFES and Discus-2cFES) and HPH (HPH 304 S FES) have been equipped with the FES system. Accordingly, Luka Žnidaršič is honored for developing a simple electrically powered propulsion system which is comparatively easy and safe to operate, and can be used for a wide range of sailplanes.

The Board of OSTIV congratulates Stefan Gehrmann, Axel Lange and Luka Žnidaršič on their outstanding achievements.

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