As America's leading propeller engineer and designer during the aeronautical design revolution of the 1920s and 1930s, Frank Walker Caldwell (1889-1974) was a significant contributor to the development of propulsion technology. Caldwell oversaw the invention, development, and innovation of the metal, ground-adjustable pitch propeller and the hydraulically-actuated two-position controllable-pitch and constant-speed propellers during his tenure as the United States government's chief propeller engineer (1917-1928) and his work in industry (1929-1938). In the process, he pioneered …showed first 75 words of 636 total…

…showed last 75 words of 636 total…present day AIAA, awarded Caldwell the Sylvanus A. Reed Award in 1935 and an honorary fellowship in 1946. He also served as the institute's president in 1941. During World War II and the early Cold War, Caldwell was the corporate director of the United Aircraft Corporation Research Division until retiring in 1955. On December 23, 1974, Caldwell passed away at his home in West Hartford, Connecticut, at the age of 85. Visit the United States Profile for more information on American pioneers.