Birds of the Same Tail Feather Configuration Prof. Dipl.-Ing. Rudolf Voit-Nitschmann (emeritus) had a lot to do with designing the 1996 Icare II solar-powered sailplane and the 2011 e-Genius. Icare II set several world records in its 20 years, most under the guidance of pilot Klaus Ohlmann. e-Genius won the award for being the quietest airplane at the Green Flight Challenge held in Santa Rosa, California, and was a close second to Pipistrel’s G4 in passenger miles per gallon (equivalent) energy use. Dipl.-Ing. Voit-Nitschmann was kind enough to explain to your editor how the propeller center came to be at the top of the tail on e-Genius. It’s a similar configuration to that on the Icare II*, and one he …