Sikorsky R-4 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 States Coast Guard and the United Kingdom's Royal Air Force and Royal Navy. In U.S. Navy and U.S. Coast Guard service, the helicopter was known as the Sikorsky HNS-1. In British service, it was known as the Hoverfly. The VS-316 was developed from the famous experimental VS-300 helicopter,
Igor Sikorsky with an international reputation, and an ardent Russian nationalist. Igor Sikorsky was an Orthodox Christian. When questioned regarding his roots, he would answer: "My family is of Russian origin. My grandfather and other ancestors from the time of Peter the Great were Russian Orthodox priests." Sikorsky's mother, Mariya Stefanovna Sikorskaya (née Temryuk-Cherkasova), was a physician who did not work professionally. She is sometimes called Zinaida Sikorsky. While homeschooling young Igor, she gave him a great love for art, especially in the life and work of Leonardo da Vinci, and the stories of Jules Verne. In 1900, at age 11, he