New Developments
The gasoline engine of the 1880s made helicopters possible. In 1907, French inventors Paul Cornu and Louis Breguet built machines that hopped briefly into the air. That same year, a French helicopter did lift a man off the ground, but only while it was held steady by four men with long poles.
At this time, Russian engineer Igor Sikorsky was also investigating helicopters; he built his first in 1910. Meanwhile, in the United States, Emile and Henry Berliner were also building helicopters. None of these machines, however, could fly very well, and they did not rival the fixed-wing aircraft that were developing rapidly in this period.
During the 1920s-1930s, interest in helicopters was spurred by the appearance of the autogiro. This was an airplane with fixed wings and a propeller, with a large four-bladed rotor on top for takeoff, landing, and steering. It demonstrated the advantages of an aircraft that can take off and land vertically-landing in city centers, for example.