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 was crushed by an engine that fell off a single-seat Morane aircraft during a landing. Sikorsky decided not to repair the seriously damaged Russky Vityaz and began working on his next brainchild — the Ilya Muromets. 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