Igor I. Sikorsky’s S-39 was built to meet the demands of the individual pilot-owner. Following the success of the S-38, Sikorsky felt that a market existed for a smaller amphibian intended for the sportsman and executive. The aircraft had a wing span of 52 feet, a wing area of 350 square feet and a gross weight of 4,000 pounds. The aircraft was capable of carrying one pilot plus four passengers. It sold completely equipped for $20,000.

The design of the S-39 started in mid 1929 as a twin engine aircraft powered by British Cirrus “Hermes Mark I” 100 horsepower engines. First flight was December 24, 1929. On December 30 the aircraft crashed due to lack of power from one engine. The twin engine concept was abandoned in favor of the small Pratt & Whitney 300 horsepower Wasp Jr. engine. First flight was early February 1930 and test pilot Boris Sergievsky commented; “During the first test flight I looped the aircraft.” More than twenty-three S-39’s were produced in spite of the depression. The little amphibian established an enviable service record. The “Spirit of Africa”, Osa and Martin Johnson’s S-39 logged more than 60,000 miles of exploratory flights in Africa. The S-39 established two Aviation World Records, was the first aircraft to use the Pratt & Whitney Wasp Jr. Engine, the first aircraft mounted on a private yacht and the first aircraft designed and produced by Sikorsky after it moved from Long Island to Connecticut.