Sikorsky Aircraft and soon increased prize money to US$25,000. In 2010, Sikorsky Aircraft pledged to increase the prize sponsorship to US$250,000. The Canadian engineers Dr. Todd Reichert and Cameron Robertson developed the world's largest ever human powered helicopter with a team from the [[University of Toronto]]. The first flight of AeroVelo Atlas was achieved in August 2012, the 64-second, 3.3-m-flight that won the prize on June 13, 2013. Sikorsky designates nearly all of its models with S-numbers; numbers S-1 through S-27 were designed by [[Igor Sikorsky]] in the Russian Empire. Later models, especially helicopters, received multiple designations by the military services using
Sikorsky S-12 Sikorsky S-12 The Sikorsky S-12 was a Russian single engine trainer aircraft completed in the spring of 1913 by the Russian Baltic Railroad Car Works while Igor Sikorsky was the chief engineer of the aircraft manufacturing division. The S-12 was a single seat mid-wing monoplane with wire-braced wings and powered by a Gnome Lambda air-cooled rotary engine rated at . It was smaller and lighter than the S-11 on which it was based, and was specifically designed to be highly maneuverable. The S-12 was the most successful monoplane Sikorsky designed during his time in Russia and twelve examples were produced.