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-34 Sikorsky S-34 The Sikorsky S-34 was a 1920s American six-seat sesquiplane, designed and built by the Sikorsky Manufacturing Corporation. Only one was built but the design led to the successful Sikorsky S-38. The S-34 was a sesquiplane amphibian with a boat hull, being powered by two tractor Wright Whirlwind J-4 engines. It had a boom-mounted twin-rudder tail unit and room inside the hull for five passengers. During a test flight in November 1927 one engine failed and the S-34 crashed and sank. Igor Sikorksy and the others onboard escaped without injury but the S-34 was destroyed. It was the first