Po-2: the slower you go, the farther you get

Like many successful aircraft, the story of the U-2 (short for ‘training aircraft 2’) began with its engine. In the 1920s, flight crews of the fledgling Soviet Union were training on outdated planes, and the lack of domestic engines forced the country to buy decommissioned engines from abroad. By July 1926, with the development of the excellent domestic M-11 engine, Polikarpov finally had the chance to design a new training aircraft. Drawing from his previous experience, he completed the design in just a few months. Just two years later, on January 7, 1928, the U-2 took its first flight. This was the plane we now recognize: a plywood biplane with a top speed slower than the stall speed of the Bf 109 fighter, yet free from many of the issues usually seen in new designs, and ready to show its capabilities.