7 The 100 Most Influential Inventors of All Time 7Corporation, occupied a large modern plant at Bridgeport,
Conn., and was producing S-38 twin-engined amphibians
in considerable numbers. In 1931 the first S-40, the
“American Clipper,” pioneered Pan American World
Airways mail and passenger routes around the Caribbean
and to South America. By the summer of 1937 Pan American
began transpacific and transatlantic service with the first
four-engined S-42 “Clipper,” the last of the Sikorsky series,
the ancestor of which had been “Le Grand” of 1913.
By the late 1930s changing requirements for military
and commercial air transport forecast the termination of
the large flying boat, and Sikorsky returned to his first
love, the helicopter. Once again he was involved in
“advanced pioneering work... where extremely little
reliable information and no piloting experience whatever
were available.” The essential aerodynamic theory and
construction techniques that had been lacking in 1910,
however, were now available. Early in 1939, with a well-
trained engineering group at his disposal, he started the
construction of the VS-300 helicopter. As he said later,
“There was a great satisfaction in knowing that, within a
short period of time, good engineering along a novel line
produced encouraging results.” On Sept. 14, 1939, the
VS-300 lifted off the ground on its first flight. Its designer
was at the controls; during his entire career Sikorsky
always insisted on making the first trial flight of any new
design himself. On May 6, 1941, in an improved machine,
he established an international endurance record of one
hour 32.4 seconds.
It is doubtful that Sikorsky at that time fully envi-
sioned the remarkable development of the vertical-lift
machine in the next 30 years. Certainly he did not antici-
pate widespread use of the helicopter as an offensive
military weapon. He regarded it as a useful tool for