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 In September 1913 an S-12 became the first Russian aircraft to perform an inside loop at the Kolomyazhskiy hippodrome north of St. Petersburg. Later an S-12 set an altitude record of . During World War I and the Russian Revolution S-12s served with the Russian Air Force and some were still in service until 1922. 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