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 VS-44 Sikorsky VS-44 The Sikorsky VS-44 was a large four-engined flying boat built in the United States in the early 1940s by Sikorsky Aircraft. The VS-44 was designed primarily for the transatlantic passenger market, with a capacity of 40+ passengers. Three units were produced: "Excalibur", "Excambian", and "Exeter". In the early 1930s, the primary mode of long-distance air travel over oceans was in flying boats, due to the ease of constructing docking facilities on shore without having to construct runways, and the possibility of malfunction forcing a sea landing. One flying boat designer was Russian immigrant Igor Sikorsky who had founded