The Bo 103 Ein Mann- Ein Blatt (One Man - One Blade) had a single main rotor blade and a single tail rotor blade (more details of the aircraft can be found in the following reference - "MBB's Helicopter History - Based on a Solid Heritage", Christina Gotzhein, Vertiflite May/June 1984, Page 95).

Only one aircraft was built. It can be seen in the German Helicopter Museum in Bückeburg.

Source: AHS Calendar September 2015