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,
Sikorsky S-29-A Sikorsky S-29-A The Sikorsky S-29-A was a twin-engine biplane airliner, first flown in 1924. It was the first aircraft that aviation pioneer Igor Sikorsky designed and built after coming to the United States, hence the special "-A" suffix signifying "America". The pilot and mechanic sat in an open cockpit between the upper wing and the tail, while up to 16 passengers were accommodated within the streamlined fuselage. With the airline industry only just emerging in the United States at that time, the S-29 failed to attract the customers that Sikorsky had hoped. It was eventually sold, however, and had a