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-29-A Sikorsky S-29-A The Sikorsky S-29-A was a twin-engine biplane airliner, first flown in 1924. It was the first aircraft that aviation pioneer Igor Sikorsky designed and built after coming to the United States, hence the special "-A" suffix signifying "America". The pilot and mechanic sat in an open cockpit between the upper wing and the tail, while up to 16 passengers were accommodated within the streamlined fuselage. With the airline industry only just emerging in the United States at that time, the S-29 failed to attract the customers that Sikorsky had hoped. It was eventually sold, however, and had a