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
Sikorsky S-8 Sikorsky S-8 The Sikorsky S-8 "Malyutka" (baby) was a small Russian single engine aircraft built by the Russian Baltic Railroad Car Works shortly after Igor Sikorsky became chief engineer of the aircraft manufacturing division in 1912. The S-8 was a two bay biplane trainer powered by a Gnome air-cooled rotary engine with the main wings and landing gear of similar design to the S-6-A. Completed early in the summer of 1912, the aircraft featured a side by side seating arrangement with controls that could be moved between the instructor and student. For improved downward visibility the lower wing had no