Sikorsky S-37

S-37
First S-37 with Gnome-Rhône 9A Jupiter engines
Role	Long-range aircraft
National origin	United States
Manufacturer	Sikorsky
First flight	1927
Number built	2
Developed from	Sikorsky S-35

The Sikorsky S-37 was an American twin-engine aircraft built by the Sikorsky Manufacturing Corporation. Both examples of the series were completed in 1927. The S-37 was specifically designed to compete for the Orteig Prize and would be the last land based fixed-wing aircraft Sikorsky would produce.

The S-37 was a two bay sesquiplane using parallel interplane struts and bracing wires. Based on the S-35 its construction was very similar, an all metal fuselage and main wing made of Duralumin and covered with fabric. The empennage featured a triple tail with the rudders placed in the slipstream of each engine and a center vertical stabilizer that was adjustable from a lever in the cockpit. The first S-37 was initially powered by 500 horsepower (373 kilowatts) Gnome-Rhône 9A Jupiter engines with the main fuel tanks located in the fairings behind each engine. A small two-cylinder hand-started auxiliary power unit mounted in the fuselage below the cockpit generated compressed air used to start the main engines. Main wheel brakes were hydraulically controlled with differential braking. The nose of the fuselage was hinged and concealed an opening 30 in (76 cm) wide by 48 in (120 cm) tall that could be used for baggage or an auxiliary fuel tank.

After the S-35 crashed and was destroyed in September 1926, Sikorsky built the first S-37 registered as X1283 for Rene Fonck to make another attempt at a non-stop Atlantic crossing and win the Orteig Prize. The aircraft was designed specifically for the transatlantic flight and was completed in the spring of 1927. Christened Ville de Paris, flight testing revealed it had sufficient payload and range to make the flight. When Charles Lindbergh won the Orteig prize the planned attempt was abandoned and the S-37 was converted into a passenger airliner for commercial use. The Jupiter engines were exchanged for 525 horsepower (391 kilowatts) Pratt & Whitney Hornet's, then Fonck's sponsors sold it to American International Airways of Argentina where it was renamed the Southern Star and re-registered as R1283. During its delivery flight on 30 June 1929, it became the first commercial transport to cross the 18,700 feet (5,700 m) high Andes mountains between Buenos Aires and Santiago carrying a payload of 5,100 pounds (2,300 kg) including eight people. Sometime afterward the aircraft was acquired by Pan American World Airways, and in 1930 was scrapped.

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