Sikorsky R-4 end of the boom near the tail rotor while others had it positioned at the midpoint of the boom. Additionally, some had short "stub" exhaust pipes from the engine while others had a much longer one which extended vertically and then aft above the main landing gear struts. Sikorsky R-4 The Sikorsky R-4 is a two-seat helicopter designed by Igor Sikorsky with a single, three-bladed main rotor and powered by a radial engine. The R-4 was the world's first large-scale mass-produced helicopter and the first helicopter used by the United States Army Air Forces, the United States Navy, the United
Igor Sikorsky designed the first heavy bomber for Russia. In 2013, "Flying" magazine ranked Sikorsky number 12 on its list of the 51 Heroes of Aviation. On March 22, 2018 the Kiev city council officially renamed Kiev airport "International Airport "Kyiv" (Zhulyany) named after Igor Sikorsky". Sikorsky was a deeply religious Russian Orthodox Christian and authored two religious and philosophical books ("The Message of the Lord's Prayer" and "The Invisible Encounter"). Summarizing his beliefs, in the latter he wrote: Igor Sikorsky Igor Ivanovich Sikorsky (, "Ígor' Ivánovič Sikórskij"; May 25, 1889 – October 26, 1972), was a Russian-American aviation pioneer in both