Today, let's look for the first helicopter. The
University of Houston's College of Engineering
presents this series about the machines that make
our civilization run, and the people whose
ingenuity created them.
It's frustrating to try to
find the first helicopter. Leonardo da Vinci had
the idea of pulling himself into the air with a
vertically mounted propeller, and the idea was
seductively simple. But for the next four and a
half centuries one inventor after another ran into
terrible problems when he actually tried to do it.
There're three kinds of heavier-than-air flight. An
airplane lifts off the ground when its propeller or
jet pulls a lifting wing through the air. An
autogyro also works like that. A propeller pulls it
forward; but instead of a wing it has another large
propeller on top. The second propeller is
free-wheeling -- it's not powered. It just whirls
in the wind and lifts the plane up. But a
helicopter propeller is powered, and it lifts the
machine directly upward. It combines both power and
lift in the same propeller.
After Leonardo, the idea of the helicopter
resurfaced in France in 1784 in the form of a
working model driven by a bow-string -- about the
same time ballooning also got its start in France.
During the 19th century, all kinds of ingenious
helicopter models were built throughout Europe.
In 1877, for example, Enrico Forlanini flew a large
steam-powered model to a height of over 40 feet in
Milan. But it wasn't until 1907 that the Frenchman
Paul Cornu hovered just off the ground for 20
seconds in a strange 32-bladed helicopter. Cornu,
like the Wright brothers four years earlier, was a
bicycle-maker.
Several other early helicopters were made, but they
were all underpowered and hard to control. When the
more manageable autogyro was developed in the 20s,
helicopters were abandoned. In 1936 the Germans
built a successful hybrid helicopter-autogyro whose
engine drove both lifting and pulling propellers.
Igor Sikorsky built the first real helicopter in
the United States in 1939. He'd tried to build one
in Russia 30 years before but had failed. Now after
designing airplanes for 30 years, and with vastly
improved technology, he succeeded. Then the Germans
dropped the forward propeller on their model,
making it into a pure helicopter. The Russians soon
copied the Germans, and -- we all had military
helicopters during WW-II.
The helicopter was in people's minds long before
the airplane. But it was a hard dream to fulfill.
Its history is littered with half-successes. The
very simplicity of combining power and lift in one
big propeller leads to awful design problems.
Leonardo was drawn in by its simplicity 500 years
ago. He couldn't see how hard it would be to
control motion with a single propeller. This
complexity, masking as simplicity, kept right on
teasing and misleading designers until 1939.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
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