After the war, he earned a physics degree at Yale University and a doctorate in aeronautical engineering from California Institute of Technology in Pasadena. At the same time, he took up soaring, that is, flying sailplanes or gliders as they are often called. He won U.S. soaring championships in 1948, 1948 and 1953, and represented the U.S. in international competition on four occasions. In 1956, he became the first American to win the world championship. He was the inventor of the MacCready Speed Ring, used by glider pilots the world over to select optimum flight speed.
MacCready founded his first company, Meteorology Research, Inc., in 1951, to pursue weather modification and atmospheric research. In 1971 he founded AeroVironment, Inc., in Monrovia, California. The company consults on environmental issues and wind power. It also designs remote-controlled electric planes, as toys and as reconnaissance tools for the Department of Defense.
Kremer offered another prize of 100,000 British pounds for the first human-powered crossing of the English Channel. In 1979, the Condor's successor, the Gossamer Albatross, flew across the Channel, and won the second Kremer Prize. MacCready's Bionic Bat won a third Kremer Prize for human-powered air speed. The bat (short for battery) uses human power not only to power the aircraft directly, but to continually recharge a battery, which stores power for continued flight.
In addition to these, MacCready created the Gossamer Penguin, the world's first successful totally solar-powered airplane, and the Solar Challenger. Unlike MacCready's previous creations, the Solar Challenger was not designed to win a competition, but to awaken the public to the possibilities of solar energy. In 1981, the Challenger flew from Paris, France to Canterbury, England, a distance of 163 miles, rising to an altitude of 11,000 feet.
MacCready did not limit himself to the development of unique aircraft. His interest in environmentally sound technology led him to develop innovative surface vehicles as well. In 1987, he built the solar-powered Sunraycer, to compete in a race across Australia. In 1990, a collaboration with General Motors resulted in the Impact, an electric car that could accelerate from zero to 60 mph in eight seconds.
Paul MacCready playfully demonstrates how wind currents
can propel a paper model of a stealth B-2 bomber.