ENGINEER'S DRAWING OF THE SIKORSKY S-40 FLYING BOAT.

ENGINEER'S DRAWING OF THE SIKORSKY S-40 FLYING BOAT.
Linsrery, J. "Sikorsky 4 Engined Passengers & Mail Amphibion. Type S-40." Sikorsky Aviation Corp, dated 5/23/29. An early original engineers drawing of the S-40 Sikorsky airplane, with 28 seats, in pencil on drafting paper. 815 x 1490 mm. Showing 5 elevations and angles of the plane, drawn at a 1:40 scale. A few rust marks on verso, small chips from the upper left and right corners, presumably where it had been previously fixed to a wall.

THE LARGEST AMPHIBIOUS AIRCRAFT OF ITS TIME,the S-40 was Pan American's first large Flying Boat, of which only 3 were built. Its maiden voyage was on November 31st 1931, from Washington D.C. with Mrs Hoover christening the plane and with Charles Lindbergh at the helm. Despite being large and cumbersome, they served as the flagships of Pan Am's clipper fleet, notching up over 10 million miles flown before they were retired in 1943.

The S-40 was originally conceived in late 1928, and this drawing shows the design both as a seaplane with floats and also with landing wheels for land use. The plan came about with the collaboration of Sikorsky Aviation and Juan Trippe, the President of Pan American Airways, who was looking for a larger passenger carrying airplane to carry hia passengers around the world. In many ways the S-40 was the prototype for the later S-42. In the 1935 S-40A the landing wheels were eliminated.