Sikorsky S-40

Sikorsky Aircraft · United States · first flew 1931 · airliner

The Sikorsky S-40 was an American amphibious flying boat built in the early 1930s for Pan American Airways. It carried 38 passengers, against eight in the earlier S-38.

Recognition (WEFT)

W — Wings	High-mounted, straight
E — Engines	4 × piston, wing-mounted
F — Fuselage	23.16 m fuselage
T — Tail	Twin fin

WEFT is AircraftIQ's four-point recognition method — how it works.

Spot it by:

Large amphibious flying boat with a parasol wing carried above the hull on struts
Four radial engines mounted on the wing
Twin-boom tail with twin fins, and a forest of struts and bracing wires

Look for a large flying boat with a wing held high above the hull on struts, four engines on the wing and twin tail fins carried on booms.

Specifications

The Sikorsky S-40 has a length of 23.16 m (76 ft).
It has a wingspan of 34.75 m (114 ft).
Its maximum speed is 217 km/h (135 mph).
Typical crew: 6.

Figures are for the representative variant described above; marks differ. See how AircraftIQ sources figures.

History

Igor Sikorsky designed it at Pan American's request for a larger passenger aeroplane, and wind-tunnel testing began in October 1928. It was a conservative enlargement of the S-38, and the many flying wires and struts caused a lot of drag. The first flight was on 6 August 1931.

Variants

Three were built. In 1935 all three were rebuilt as the S-40A with supercharged 660 hp Hornet T2D1 engines in place of the original 575 hp Hornet Bs, and the landing gear was removed.

Where you'll see it

Passenger service began on 19 November 1931 on a flight from Miami to the Panama Canal Zone, piloted by Charles Lindbergh. The first aircraft, American Clipper, gave the "Clipper" name to Pan American's large flying boats. The three were retired around 1940 and used by the US Navy as trainers in the Second World War.

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