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
Igor Sikorsky Kiev Polytechnic Institute. After the academic year, Sikorsky again accompanied his father to Germany in the summer of 1908, where he learned of the accomplishments of the Wright brothers' Flyer and Ferdinand von Zeppelin's dirigible. Sikorsky later said about this event: "Within twenty-four hours, I decided to change my life's work. I would study aviation." By the start of World War I in 1914, Sikorsky's airplane research and production business in Kiev was flourishing, and his factory made bombers during the war. After the Bolshevik revolution began in 1917, Igor Sikorsky fled his homeland, because the new government threatened to