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 Russky Vityaz Sikorsky Russky Vityaz The Sikorsky Russky Vityaz (), or Russian Knight, previously known as the Bolshoi Baltisky () "(The Great Baltic)" in its first four-engined version, was the first four-engine aircraft in the world, designed by Igor Sikorsky and built at the Russian Baltic Railroad Car Works ("Russo-Baltiiskyi Vagonnyi Zavod" or "R-BVZ") in Saint Petersburg in early 1913. Sikorsky conceived the S-21 design in 1911, when no known aircraft could lift more than . The carrying capacity record belonged to the French pilot Ducis, who had flown with a load of . On hearing about the construction of the "Russky